Patent Application
20220283182
The disclosure relates to a kit and a method for combined detection of procalcitonin (“PCT” herein) and a soluble CD14 subtype (“sCD14-ST” or “Presepsin” or herein) in a sample to be tested, and the use thereof.
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. It is reported in literatures that the incidence of sepsis is increasing year by year, and the fatality rate remains high, which has seriously threatened human life and health. According to the treatment guidelines for sepsis, early diagnosis is an effective way to improve the survival rate of patients with sepsis. Blood culture is the “gold standard” for diagnosis of sepsis; however, it has a low positive rate and a long culture time. Therefore, there is an urgent need to find a biomarker with high specificity and sensitivity for early diagnosis and accurate prediction of sepsis.
Therefore, the disclosure provides a kit for combined detection of PCT and Presepsin in a sample to be detected and a method for combined detection of PCT and Presepsin in a sample to be detected. In addition, the disclosure also provides use of combined detection of PCT and Presepsin in a sample to be detected in the diagnosis and prognosis of sepsis in a patient.
A first aspect of the disclosure relates to a kit for combined detection of PCT and Presepsin in a sample to be tested, the kit comprising: a capture antibody mixture, the capture antibody mixture comprising a procalcitonin capture antibody coated on a solid phase and a soluble CD14 subtype capture antibody coated on a solid phase; and a detection antibody mixture, the detection antibody mixture comprising a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody.
A second aspect of the disclosure relates to a method for combined detection of PCT and Presepsin in a sample to be tested, the method comprising:
mixing a sample to be tested, a procalcitonin capture antibody coated on a solid phase, and a soluble CD14 subtype capture antibody coated on a solid phase to obtain a the mixture of the sample to be detected the sample to be tested, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody, so that the procalcitonin capture antibody coated on the solid phase binds to the procalcitonin in the sample to be tested, and the soluble CD14 subtype capture antibody coated on the solid phase binds to the soluble CD14 subtype in the sample to be tested;
washing the mixture of the sample to be tested, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody to remove unbound substances;
adding a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody to the washed mixture of the sample to be tested and the capture antibody mixture, so that the labeled procalcitonin detection antibody binds to the procalcitonin bound on the procalcitonin capture antibody to form a sandwich complex, and the labeled soluble CD14 subtype detection antibody binds to the soluble CD14 subtype bound on the soluble CD14 subtype capture antibody to form a sandwich complex;
washing the sandwich complexes to remove unbound substances;
adding a detection substrate to the washed sandwich complexes to detect the combined concentration level of the procalcitonin and the soluble CD14 subtype in the sample to be tested.
A third aspect of the disclosure relates to use of a soluble CD14 subtype antibody and a procalcitonin antibody in the preparation of an analysis reagent for identifying whether a patient suffers from sepsis, where a sample to be tested from the patient, a procalcitonin capture antibody coated on a solid phase and a soluble CD14 subtype capture antibody coated on a solid phase are mixed, and then a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody are added to detect the combined concentration value of the procalcitonin and the soluble CD14 subtype in the sample to be tested, and the increase in the combined concentration level relative to a reference value is associated with an increase in possibility of the patient suffering from sepsis.
A fourth aspect of the disclosure relates to use of a soluble CD14 subtype antibody and a procalcitonin antibody in the preparation of an analysis reagent for evaluating the prognosis of a suspected sepsis patient, where a sample to be tested from the patient, a procalcitonin capture antibody coated on a solid phase and a soluble CD14 subtype capture antibody coated on a solid phase are mixed, and then a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody are added to detect the combined concentration value of the procalcitonin and the soluble CD14 subtype in the sample to be tested, and the increase in the combined concentration level relative to a reference value is associated with an increase in risk of death in the suspected sepsis patient.
The kit, method and use provided in the embodiments of the disclosure may detect a combined signal value of PCT and Presepsin in a sample in a reaction system, the comparison between the combined signal value and a reference value may be used for evaluating the possibility of a patient suffering from sepsis and evaluating the prognosis of a suspected sepsis patient, and comparing to respectively detecting PCT or Presepsin in a sample, the method has a more efficient diagnosis and a better prognostic power. In addition, for combined detection of PCT and Presepsin in a sample, only one detection is required, so that the economic cost and time cost of the sample testing may be reduced, the blood consumption may be decreased, and also the effect of reagents of different production batches on the detection results may be reduced, which is conducive to reagent production and instrument automatization.
Embodiments of the disclosure are described below with reference to the accompanying drawings. The objectives and advantages of the disclosure will be further understood from the following detailed description and accompanying drawings. The accompanying drawings show the following:
The disclosure will be described below in more detail by way of specific embodiments. However, these embodiments are only representative and the disclosure should in no way be construed as being limited to these embodiments.
Currently, in the diagnosis of sepsis, clinically widely used biomarkers are interleukin 6 (IL-6), C reactive protein (CRP) and procalcitonin (PCT). CRP is an acute phase protein synthesized by the liver. It has strong sensitivity to bacterial infection, but has low specificity, long half-life and no clear correlation with the progression of sepsis. The peak values of IL-6 appear early and can rise before clinical symptoms appear, which is beneficial for early diagnosis of sepsis, but has low sensitivity. PCT is widely used in the diagnosis of infection and sepsis. PCT is often not elevated in nonbacterial infections. PCT is often not significantly elevated in certain types of infections, such as skin and soft tissue infections. PCT is not suitable for determining the prognosis of septic shock infection in perioperative abdominal infections. In addition, in some non-infectious diseases, there is also an elevation in PCT. Although PCT has been shown to have a clear correlation with infection, false-positive diagnoses are prone to occur in some cases such as trauma, surgery, and burns. Therefore, PCT is not a perfect marker for the diagnosis of infection and sepsis, and PCT alone is not reliable for the diagnosis of infection and sepsis.
Soluble CD14 subtype (referred to as sCD14-ST or Presepsin for short), as a new biological indicator of sepsis, has potential application value in the diagnosis and prognosis of sepsis and in the guidance of the use of antimicrobial drugs in sepsis. Presepsin is an N-terminal fragment of sCD14 after being cleaved by proteases such as cathepsin D in the plasma, and has a relative molecular weight of about 13 kDa. Shirakawa et al. established an endotoxic shock model and a cecal ligation and perforation model (CLP model) in rabbits and found that the former did not result in an elevation in the concentration of Presepsin, whereas the CLP model resulted in a significant elevation. Therefore, it is believed that the elevation of Presepsin is resulted from phagocytosis caused by bacterial infection, rather than by physiological resistance to inflammation. At present, Presepsin is considered to have high specificity in evaluating the severity and prognosis of sepsis, and can accurately guide the use of antimicrobial drugs in sepsis. Nonetheless, Presepsin remains deficient as a diagnostic label in certain infection scenarios.
Therefore, provided in the embodiments of the disclosure are a kit and a method for combined detection of PCT and Presepsin in a sample to be tested with a more efficient diagnosis and a better prognostic capability, and the use thereof.
In the context of the disclosure, when these expressions, characteristics, values or ranges are referred to in conjunction with expressions such as “about, substantially, generally, at least, at a minimum”, the disclosure also includes the exact or precise expressions, characteristics, values or ranges.
In the disclosure, the term “detection” may be used interchangeably with the terms such as “determination”, “quantification” and “analysis”, and is meant to encompass both quantitative and qualitative determinations. The test in the disclosure is performed in vitro.
In the scope of the disclosure, the term ROC (receiver operating characteristic) curve refers to a curve obtained by dividing the diagnostic test results into several critical points, using the sensitivity corresponding to each critical point as the ordinate and the specificity as the abscissa, and plotting. The ROC curve is an effective tool for comprehensive and accurate evaluation of diagnostic tests. Another effect of the ROC curve is to determine the optimal threshold for detection. In most cases when a critical point is determined by an ROC curve method, a point as close to the upper left as possible on the curve is selected, and is determined as the optimal critical point in combination with the professional situation. In the application, according to the ROC curve, combined with the sensitivity and specificity results of each point of tangency, a point of tangency with the largest Youden index as close to the upper left as possible on the curve is selected as the optimal critical point, so that the sensitivity and specificity of the test are high, and the misdiagnosis rate and missed diagnosis rate are low.
In the disclosure, the kit for combined detection of PCT and Presepsin in a sample to be tested is also referred to as a “combined detection kit”.
The first aspect of the disclosure provides a kit (a combined detection kit) for combined detection of PCT and Presepsin in a sample to be tested, comprising: a solid phase component, the solid phase component including a procalcitonin capture antibody (a PCT capture antibody) coated on a solid phase and a soluble CD14 subtype capture antibody (a Presepsin capture antibody) coated on a solid phase; and a labeling component, the labeling component including a labeled procalcitonin detection antibody (a PCT detection antibody) and a labeled soluble CD14 subtype detection antibody (a Presepsin detection antibody).
In some embodiments of the first aspect of the disclosure, the solid phase component is present in the kit in the form of a capture antibody mixture, where the capture antibody mixture is mixed with a procalcitonin capture antibody coated on a solid phase and a soluble CD14 subtype capture antibody coated on a solid phase. In other embodiments, the solid phase component may also include a procalcitonin capture antibody component coated on a solid phase and a soluble CD14 subtype capture antibody component coated on a solid phase that are separately packaged from each other.
Similarly, in some embodiments of the first aspect of the disclosure, the labeling component is present in the kit in the form of a detection antibody mixture, where the detection antibody mixture is mixed with a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody. In other embodiments, the labeling component may also include a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody that are separately packaged from each other.
In some embodiments of the first aspect of the disclosure, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody are separately coated on different solid phases. Certainly, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody may also be co-coated on the same solid phase.
In some embodiments of the first aspect of the disclosure, the mixing ratio of a PCT capture antibody to a Presepsin capture antibody is determined according to the principle of maximizing the diagnostic efficacy for diagnosing sepsis, that is, the mixing ratio is selected according to the principle of maximizing the AUC of the ROC curve. The mixing ratio of a PCT capture antibody to a Presepsin capture antibody in a solid phase component may be in the range of about 5:1 to about 1:5, preferably in the range of about 3:1 to about 1:5, more preferably in the range of about 3:1 to 1:3, in particular about 3:1 or 1:1 or 1:3, and more particularly preferably about 1:3.
In some embodiments of the first aspect of the disclosure, the mixing ratio of a PCT detection antibody to a Presepsin detection antibody is determined according to the principle of maximizing the diagnostic efficacy for diagnosing sepsis, that is, the mixing ratio is selected according to the principle of maximizing the AUC of the ROC curve. The mixing ratio of a PCT detection antibody to a Presepsin detection antibody in a labeling component may be in the range of about 5:1 to about 1:5, preferably in the range of about 3:1 to about 1:5, more preferably in the range of about 3:1 to 1:3, in particular about 3:1 or 1:1 or 1:3, and more particularly preferably about 1:3.
In some embodiments of the first aspect of the disclosure, the mixing ratio of a PCT capture antibody to a Presepsin capture antibody in a solid phase component may be equal to the mixing ratio of a PCT detection antibody to a Presepsin detection antibody in a labeling component, and the mixing ratios are preferably 1:3.
In some embodiments of the first aspect of the disclosure, both a PCT capture antibody and a PCT detection antibody are commercially available, where the PCT capture antibody is, for example, Anti-hPCT 4003 SPTN-5 (Medix Biochemica), and the PCT detection antibody is, for example, Anti-hPCT 4051 SPTN-5 (Medix Biochemica).
In some embodiments of the first aspect of the disclosure, the soluble CD14 subtype capture antibody specifically recognizes an epitope composed of the amino acid sequence of SEQ ID No.42, and the soluble CD14 subtype capture antibody the soluble CD14 subtype capture antibody comprises:
(i) heavy chain variable region (VH) complementarity determining regions (CDRs):
VH CDR1: X1X2X3MX4;
VH CDR2: YIX5X6ADX7;
VH CDR3: X8X9X10AX11;
and
(ii) light chain variable region (VL) complementarity determining regions (CDRs):
VL CDR1: KX12X13X14N;
VL CDR2: LX15X16;
VL CDR3: VX17X18X19;
where X1 to X19 are one or more of the amino acid sequences listed below as options:
X1=any one of the amino acids;
X2═F or V; X3=A, E or K; X4=A or L;
X5=SYMGS, SSGSS, AYTMY, TYSGS or SSKSS;
X6=GAYY, TIYY, AKYY, TKAS or SNLA;
X7=AKLG, TVKG, SYTA, MTKG or YGNT;
X8=A or Q; X9=G or Q; X10=Q or F; X11=M, Y or V;
X12=YYAS, SSAT, SSQS or SGSS;
X13=AAKL, LLAT, LLYS or KAAS;
X14=YRNIKL, TWAKGN, NGKTYL or YTNGAL;
X15=VQS, KTS, QTS or VSK;
X16=LAS, LDS, LTA or DSK;
X17=G, A, S or Q;
X18=GTH, GNT, GTA or TAI;
X19=FITA, FPRT, YGHV or NYGH.
In some embodiments of the first aspect of the disclosure, the soluble CD14 subtype capture antibody comprises VH CDR1, VH CDR2 and VH CDR3, as well as VL CDR1, VL CDR2 and VL CDR3, where VH CDR1, VH CDR2 and VH CDR3, as well as VL CDR1, VL CDR2 and VL CDR3 are selected from the amino acid sequences described in Table 1 (see Table 1).
In some embodiments of the first aspect of the disclosure, the soluble CD14 subtype capture antibody comprises VH CDR1, VH CDR2 and VH CDR3, as well as VL CDR1, VL CDR2 and VL CDR3, where VH CDR1, VH CDR2 and VH CDR3, as well as VL CDR1, VL CDR2 and VL CDR3 are selected from the amino acid sequences described in Table 2 (see Table 2).
In some embodiments of the first aspect of the disclosure, the soluble CD14 subtype capture antibody comprises VH CDR1, VH CDR2 and VH CDR3, as well as VL CDR1, VL CDR2 and VL CDR3, which are any one of the following 1) to 62):
1) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 1, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
2) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 1, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 41;
3) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 1, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
4) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 1, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
5) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 1, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
6) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 35;
7) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
8) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
9) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
10) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
11) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 9, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
12) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 35;
13) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 36;
14) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
15) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 41;
16) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
17) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 35;
18) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
19) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
20) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 15, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
21) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
22) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 36;
23) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 41;
24) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
25) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
26) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
27) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
28) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 9, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 36;
29) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 9, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
30) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 41;
31) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 15, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
32) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 15, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
33) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
34) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
35) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
36) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
37) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
38) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
39) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
40) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
41) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
42) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 8, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
43) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
44) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 15, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
45) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 40;
46) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
47) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 36;
48) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
49) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
50) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
51) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
52) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 27, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 34;
53) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 19, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 24, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 31, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
54) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 15, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
55) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 15, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 26, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 28, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
56) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
57) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
58) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 6, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 7, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
59) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 6, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 10, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 25, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
60) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 6, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
61) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 6, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 11, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 14, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39; or
62) VH CDR1 composed of the amino acid sequence of SEQ ID NO: 6, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38.
In some embodiments of the first aspect of the disclosure, the soluble CD14 subtype capture antibody comprises:
(a) VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 1, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 17, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 32, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33;
(b) VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 2, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 37;
(c) VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 9, and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38;
(d) VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 5, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 18, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 39;
(e) VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 4, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 12, and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 23, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 33; or
(f) VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 6, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 13, and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 20, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 22, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 30, and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38.
In some embodiments of the first aspect of the disclosure, a Presepsin capture antibody may be derived from an anti-soluble CD14 subtype monoclonal antibody or an antigen-binding antibody fragment thereof secreted and produced by a hybridoma cell strain with the deposit number of CGMCC NO.18536, and a Presepsin detection antibody may be derived from an anti-soluble CD14 subtype polyclonal antibody secreted and produced by a hybridoma cell strain with the deposit number of CGMCC NO.18536, which was deposited on Oct. 23, 2019, with China General Microbiological Culture Collection Center, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, People's Republic of China.
In some embodiments of the first aspect of the disclosure, a solid phase carrier may be selected from a magnetic microsphere, a chip, a test paper, etc., preferably a magnetic microsphere, and more preferably a superparamagnetic bead.
In some embodiments of the first aspect of the disclosure, a PCT detection antibody and a Presepsin detection antibody are labeled with a signal label, which may be, for example, a chemiluminescent label (such as an alkaline phosphatase, luminol, isoluminol, an acridinium ester, and a horseradish peroxidase), an electrochemiluminescent label (e.g., ruthenium terpyridine), a quantum dot (such as a gold quantum dot, a CdSe quantum dot, and a ZnCdSe quantum dot), a fluorescent microsphere, or a combination thereof.
In some embodiments of the first aspect of the disclosure, a capture antibody mixture may further include a capture antibody specific for other markers, and accordingly, a detection antibody mixture comprises a detection antibody specific for the other markers, where the other markers may be selected from at least one of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor (TNF-α), serum athermoprotein A (SAA), heparin-binding protein (HBP), soluble urokinase-type plasminogen activator receptor (suPAR), interleukin-1β (IL-1β), interleukins such as IL-2, IL-4, IL-8, IL-10, IL-12, IL-13 and IL-18, tissue inhibitor of metalloproteinase-1 (TIMP-1), soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), matrix metalloproteinase 9 (MMP-9), pro-adrenomedullin (Pro-ADM), Toll-like receptor (TLR2), α2-macroglobulin (A2M), troponin I (TnI), C—C chemokine ligand 2 (CCL2), CD163, osteopontin (OPN), D-Dimer, lipopolysaccharide binding protein (LBP), (1,3)-β-D-glucan (BG), coagulation factor, angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), vascular endothelial growth factor, γ-interferon human, immunoglobulin E, human immunoglobulin A, human immunoglobulin M, human immunoglobulin G, and human urinary microalbumin. Preferably, the other markers may be selected from at least one of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor (TNF-α), serum athermoprotein A (SAA), and heparin-binding protein (HBP).
In some embodiments of the first aspect of the disclosure, a PCT capture antibody may also be replaced with a capture antibody specific for other markers, and accordingly, a detection antibody mixture comprises a detection antibody specific for the other markers instead of a PCT detection antibody, where the other markers may be, for example, one of the markers listed above.
The second aspect of the disclosure relates to a method for combined detection of PCT and Presepsin in a sample to be tested, including the following steps:
mixing a sample to be tested, a procalcitonin capture antibody coated on a solid phase, and a soluble CD14 subtype capture antibody coated on a solid phase, so that the procalcitonin capture antibody coated on the solid phase binds to the procalcitonin in the sample to be tested, and the soluble CD14 subtype capture antibody coated on the solid phase binds to the soluble CD14 subtype in the sample to be tested;
adding a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody to the mixture of the sample to be tested, the procalcitonin capture antibody, and the soluble CD14 subtype capture antibody, so that the labeled procalcitonin detection antibody binds to the procalcitonin bound on the procalcitonin capture antibody to form a sandwich complex and the labeled soluble CD14 subtype detection antibody binds to the soluble CD14 subtype bound on the soluble CD14 subtype capture antibody to form a sandwich complex;
adding a detection substrate to the sandwich complexes to detect the combined concentration level of the procalcitonin and the soluble CD14 subtype in the sample to be tested.
In some embodiments of the second aspect of the disclosure, the method specifically includes:
mixing a sample to be tested, a procalcitonin capture antibody coated on a solid phase, and a soluble CD14 subtype capture antibody coated on a solid phase, so that the procalcitonin capture antibody coated on the solid phase binds to the procalcitonin in the sample to be tested, and the soluble CD14 subtype capture antibody coated on the solid phase binds to the soluble CD14 subtype in the sample to be tested;
washing the mixture of the sample to be tested, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody to remove unbound substances;
adding a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody to the washed mixture, so that the labeled procalcitonin detection antibody binds to the procalcitonin bound on the procalcitonin capture antibody to form a sandwich complex and the labeled soluble CD14 subtype detection antibody binds to the soluble CD14 subtype bound on the soluble CD14 subtype capture antibody to form a sandwich complex;
washing the sandwich complex to remove unbound substances;
adding a chemiluminescent substrate to the washed sandwich complexes to detect the number of photons generated by the reaction, thereby obtaining a combined signal value of the procalcitonin and the soluble CD14 subtype in the sample to be tested, where the combined signal value represents the combined concentration level of the procalcitonin and the soluble CD14 subtype in the sample to be tested, which is directly proportional to the combined concentration value of the procalcitonin and the soluble CD14 subtype in the sample to be tested.
In some embodiments of the second aspect of the disclosure, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody are separately coated on different solid phases. Alternatively, the procalcitonin capture antibody and the soluble CD14 subtype capture antibody may also be co-coated on the same solid phase.
In some embodiments of the second aspect of the disclosure, a PCT capture antibody and a Presepsin capture antibody are added to a sample to be tested together or separately.
In some embodiments of the second aspect of the disclosure, a PCT detection antibody and a Presepsin detection antibody are added to a sample to be tested together or separately.
In some embodiments of the second aspect of the disclosure, the addition ratio of a PCT capture antibody to a Presepsin capture antibody is determined according to the principle of maximizing the diagnostic efficacy for diagnosing sepsis, that is, the mixing ratio is selected according to the principle of maximizing the AUC of the ROC curve. The ratio of a PCT capture antibody to a Presepsin capture antibody which are added to the sample to be tested may be in the range of about 5:1 to about 1:5, preferably in the range of about 3:1 to about 1:5, more preferably in the range of about 3:1 to 1:3, in particular about 3:1 or 1:1 or 1:3, and more particularly preferably about 1:3.
In some embodiments of the second aspect of the disclosure, the addition ratio of a PCT detection antibody to a Presepsin detection antibody is determined according to the principle of maximizing the diagnostic efficacy for diagnosing sepsis, that is, the mixing ratio is selected according to the principle of maximizing the AUC of the ROC curve. The amount ratio of a PCT detection antibody to a Presepsin detection antibody which are added to the sample to be tested may be in the range of about 5:1 to about 1:5, preferably in the range of about 3:1 to about 1:5, more preferably in the range of about 3:1 to 1:3, in particular about 3:1 or 1:1 or 1:3, and more particularly preferably about 1:3.
In some embodiments of the second aspect of the disclosure, the addition ratio of a PCT capture antibody to a Presepsin capture antibody may be equal to the addition ratio of a PCT detection antibody to a Presepsin detection antibody, and the addition ratios are preferably 1:3.
In some embodiments of the second aspect of the disclosure, a sample to be tested may be blood and a blood component such as serum or plasma, preferably a plasma sample.
For other features of the second aspect of the disclosure, such as a PCT capture antibody/detection antibody, a Presepsin capture antibody/detection antibody, a label, and a solid phase, reference may be made to the related description in the first aspect of the disclosure, and details are not described herein again.
The third aspect of the disclosure relates to the use of the soluble CD14 subtype antibody and the procalcitonin antibody in the preparation of an analysis reagent for identifying whether a patient suffers from sepsis, where a sample to be tested from the patient, a procalcitonin capture antibody coated on the solid phase and a soluble CD14 subtype capture antibody coated on the solid phase are mixed, and then a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody are added to detect a combined concentration level of the procalcitonin and the soluble CD14 subtype in the sample to be tested, and an increase in the combined concentration level relative to the reference value is associated with an increase in possibility that the patient suffers from sepsis.
In some embodiments of the third aspect of the disclosure, a chemiluminescent substrate is used to detect the number of photons generated by the reaction of a sample to be tested from a patient, a capture antibody and a detection antibody, thereby obtaining a combined signal value of the procalcitonin and the soluble CD14 subtype in the sample to be tested, where the combined signal value represents the combined concentration value of the procalcitonin and the soluble CD14 subtype in the sample to be tested. The combined signal value of PCT and Presepsin in a sample to be tested may be compared with a threshold value to obtain a combined detection factor, for example, combined detection factor=combined signal value of a sample to be tested/threshold value. The combined detection factor is then compared with a reference value to evaluate whether a patient suffers from sepsis.
In some embodiments of the third aspect of the disclosure, the increase in the combined signal value relative to a reference value is positively correlated with an increase in possibility that a patient suffers from sepsis.
In some embodiments of the third aspect of the disclosure, a sample to be tested is detected with a combined detection kit according to the disclosure, and an ROC curve is established. According to the ROC curve, a threshold value is determined, and the combined signal value is compared with the threshold value. When a combined detection factor is ≥1, a patient is at high risk of suffering from sepsis; when the combined detection factor is <1, the patient is at low risk of suffering from sepsis.
In some embodiments of the third aspect of the disclosure, the combined signal value of the procalcitonin and the soluble CD14 subtype in the sample to be tested from a patient is detected within 72 hours after the patient is suspected of suffering from sepsis.
A fourth aspect of the disclosure relates to use of a soluble CD14 subtype antibody and a procalcitonin antibody in the preparation of an analysis reagent for evaluating the prognosis of a suspected sepsis patient, where a sample to be tested from the patient, a procalcitonin capture antibody coated on a solid phase and a soluble CD14 subtype capture antibody coated on a solid phase are mixed, and then a labeled procalcitonin detection antibody and a labeled soluble CD14 subtype detection antibody are added to detect a combined concentration level of the procalcitonin and the soluble CD14 subtype in the sample to be tested, and an increase in the combined concentration level relative to a reference value is associated with an increase in risk of death in the suspected sepsis patient.
In some embodiments of the fourth aspect of the disclosure, a chemiluminescent substrate is used to detect the number of photons generated by the reaction of a sample to be tested from a patient, a capture antibody and a detection antibody, thereby obtaining a combined signal value of the procalcitonin and the soluble CD14 subtype in the sample to be tested, where the combined signal value represents the combined concentration value of the procalcitonin and the soluble CD14 subtype in the sample to be tested. The combined signal value of PCT and Presepsin in a sample to be tested may be compared with a threshold value to obtain a combined detection factor, for example, combined detection factor=combined signal value of a sample to be tested/threshold value. The combined detection factor is then compared with a reference value to evaluate the risk of death in a suspected sepsis patient.
In some embodiments of the fourth aspect of the disclosure, the increase in the combined signal value relative to a reference value is positively correlated with an increase in risk of death in a suspected sepsis patient.
In some embodiments of the fourth aspect of the disclosure, the combined signal value of the procalcitonin and the soluble CD14 subtype in the sample to be tested from a patient is detected within 72 hours after the patient is suspected of suffering from sepsis.
The combined detection kit of the disclosure was prepared by the following method: a PCT capture antibody and a Presepsin capture antibody were mixed at a certain ratio, and then the mixture was coated on the surface of a solid phase carrier; and next, a PCT detection antibody and a Presepsin detection antibody were mixed at a certain ratio, and then the mixture was labeled with a signal label.
First, a PCT capture antibody and a Presepsin capture antibody were mixed at a concentration ratio of about 5:1 to about 1:5, respectively, and the mixture was coated on the surface of a solid phase carrier, where the solid phase carrier was preferably a superparamagnetic bead. A PCT detection antibody and a Presepsin detection antibody were also mixed at a ratio of about 5:1 to about 1:5, and the mixture was labeled with a signal label, where the signal label is preferably an alkaline phosphatase. In this example, the ratio of the PCT capture antibody to the Presepsin capture antibody was the same as the ratio of the PCT detection antibody to the Presepsin detection antibody. Then, the coated capture antibody mixture and the labeled detection antibody mixture were diluted with a buffer containing about 50 mM of MES (2-morpholinoethanesulfonic acid) and about 0.5 M of NaCl, with pH of about 6.0. Upon dilution, the concentration of the coated capture antibody mixture was in the range of about 1 μg/mL to about 10 μg/mL, preferably about 2 μg/mL, and the concentration of the labeled detection antibody mixture was in the range of about 0.5 μg/mL to about 5 μg/mL, preferably about 1 μg/mL.
Samples with known clinical diagnostic results were selected, including >50 negative samples for sepsis and >50 positive samples for sepsis. The kit prepared by the method described above was selected to detect a sample to be tested, and an ROC curve was established to calculate the AUC area, as shown in Table 3 and
It can be seen from Table 3 and
In subsequent experiments, the mixing ratio of the PCT capture antibody to the Presepsin capture antibody was selected to be about 1:3, and similarly, the mixing ratio of the PCT detection antibody to the Presepsin detection antibody was selected to be about 1:3.
A capture antibody mixture coated on a solid phase carrier and a labeled detection antibody mixture in the combined detection kit according to the embodiments of the disclosure, for example, the combined detection kit prepared according to Example 1 were mixed with a sample to be tested, where the PCT biomarker in the sample to be tested was bound with the PCT capture antibody and the PCT detection antibody to form a sandwich structure; similarly, the Presepsin biomarker in the sample to be tested was bound with the Presepsin capture antibody and the Presepsin detection antibody to form a sandwich structure; an unbound detection antibody was removed by washing; the signal generated by a signal label labeled with a detection antibody was detected by an instrument for example, CL-2000i, CL-900 i, CL-6000 i or CL-1000 i chemiluminescent analyzer from Shenzhen Mindray Bio-medical Electronics Co., Ltd., thereby obtaining a combined signal value of PCT and Presepsin in the sample to be tested, where the intensity of the combined signal value is directly proportional to the concentration of Presepsin and PCT in the sample to be tested. 215 samples with known clinical diagnostic results were selected, including 95 negative samples for sepsis and 120 positive samples for sepsis. With the help of a detection device, such as the CL-2000i analyzer from Shenzhen Mindray Bio-medical Electronics Co., Ltd., the above-mentioned 215 samples were detected by the method of this example, and an ROC curve was established, as shown in
By using the method of the embodiments of the disclosure, the combined detection kit according to the embodiments of the disclosure was used to detect plasma samples from 141 suspected sepsis patients within 72 hours after admission to hospital, thereby obtaining a combined signal value; and in addition, the concentration values of PCT and Presepsin in the plasma samples from 141 suspected sepsis patients were detected, respectively. According to the detection results, ROC curves corresponding to detection of PCT alone, detection of Presepsin alone, and combined detection of PCT and Presepsin were established, respectively, as shown in
The combined detection kit according to the embodiments of the disclosure was used to detect 200 samples, including 60 healthy people, 52 people with local infection, 51 patients with sepsis, and 37 people with septic shock. The diagnostic criteria are based on Sepsis 3.0 (Singer M, Deutschman C S, Seymour C W, et al. The Third international consensus definitions for sepsis and septic shock (Sepsis-3) [J]), and the detection results of different groups (see Table 4) show that with the development of infection, the value of the combined detection factor is increasing.
By using the method of the embodiments of the disclosure, the combined detection kit according to the embodiments of the disclosure was used to detect plasma samples from 88 suspected sepsis patients and the prognosis of the patients within 30 days was tracked. The relationship graph of survival probability curve within 30 days after the suspected sepsis patients were admitted to hospital was obtained by using a Kaplan-Meier statistical analysis method, as shown in
In addition, taking the above-mentioned 88 suspected sepsis patients as the object, an ROC curve was used to compare the concentration values of combined detection, detection of PCT alone, and detection of Presepsin alone in patients within 72 hours after admission to hospital with the prognostic power of survival probability in patients within 30 days after admission to hospital. As shown in
Step 1.1 Expression of a Soluble CD14 Subtype Immunogen
The soluble CD14 subtype immunogen is expressed by using a prokaryotic expression system and a eukaryotic expression system, respectively. The corresponding process is described below in detail.
(1) Expression of a soluble CD14 subtype immunogen by using a prokaryotic expression system
A target DNA sequence was synthesized, and then a pET30a expression vector was selected to construct a plasmid which was transformed into E. coli BL21star (DE3) to obtain a prokaryotic expression engineering strain. The recombinant plasmid was induced to be highly expressed in an E. coli expression system by an IPTG (isopropyl thiogalactoside) method. The target protein which mainly existed in an inclusion body, was purified and obtained by a Ni2+ NTA affinity column. The target protein had a sequence of Thr Thr Pro Glu Pro Cys Glu Leu Asp Asp Glu Asp Phe Arg Cys Val Cys Asn Phe Ser Glu Pro Gln Pro Asp Trp Ser Glu Ala Phe Gln Cys Val Ser Ala Val Glu Val Glu Ile His Ala Gly Gly Leu Asn Leu Glu Pro Phe Leu Lys Arg Val Asp Ala Asp Ala Asp Pro Arg Gln Tyr Ala (SEQ ID No. 43). As shown in
(2) Expression of a Soluble CD14 Subtype Immunogen by Using a Eukaryotic Expression System
A target DNA sequence was synthesized, and then a pcDNA3.4 expression vector was selected to construct a plasmid. An HEK293-6E expression system was used, and the culture conditions were as follows: the expression system was cultured in serum-free FreeStyle™ 293 Expression Medium (Thermo Fisher Scientific) matrix at 37° C. and 5% CO2. The constructed plasmid was transfected in the 293-6E expression system by using a transient transfection method. After 6 days of culture, a cell culture supernatant was collected. The supernatant was filtered and subjected to affinity purification. The purified protein was digested by using optimized experimental conditions, and a target protein was obtained after purification. As shown in
Step 1.2 Preparation of an Anti-Soluble CD14 Subtype Polyclonal Antibody
The proteins (i.e., antigens) expressed and purified by the prokaryotic system and the eukaryotic system obtained in Step 1.1 were mixed at a certain ratio, and the mixture was coupled with a carrier protein keyhole limpet hemocyanin (referred to as KLH for short), so that the resulting product was used as an immunogen to immunize New Zealand white rabbits according to the following steps: the immunogen was diluted with physiological saline, and then mixed with an adjuvant such as an incomplete Freund's adjuvant (Sigma-Aldrich) at 1:1. The antigen and the adjuvant were thoroughly mixed to form a stable emulsion, which was injected subcutaneously under the skin around the shoulders of New Zealand white rabbits and intramuscularly in the hind thighs thereof. Each region was immunized with about ¼ of the immunogen, and the antigen amount of each immunization was about 100 μg to 500 μg, with a total of four immunizations and an interval of each immunization of 2 weeks. After the fourth immunization, the antiserum of New Zealand white rabbits was collected and subjected to antigen affinity purification to obtain a soluble CD14 subtype polyclonal antibody. The results of SDS-PAGE and Western Blot for the anti-soluble CD14 subtype polyclonal antibody are shown in
Step 1.3 Preparation of an Anti-Soluble CD14 Subtype Monoclonal Antibody
The proteins (i.e., antigens) expressed and purified by the prokaryotic system and the eukaryotic system obtained in Step 1.1 were mixed at a certain ratio, and the mixture was coupled with a carrier protein keyhole limpet hemocyanin (referred to as KLH for short), so that the resulting product was used as an immunogen to immunize mice according to the following steps: at an initial immunization, the antigen (10 μg to 50 μg) was mixed with an adjuvant such as a complete Freund's adjuvant (Sigma-Aldrich) at 1:1, followed by subcutaneous multi-point injection. After 3 weeks, a second immunization was performed, whose dose was the same as that at the initial immunization, and an incomplete Freund's adjuvant (Sigma-Aldrich) was added for subcutaneous injection. After another 3 weeks, a third immunization was performed, whose dose was the same as that at the initial immunization, without the addition of an adjuvant. After 3 weeks, a booster immunization was performed at doses ranging from 100 μg to 500 μg. Three days after the booster immunization, the spleen was obtained for fusion. After the third immunization, the titer of antiserum in mice was evaluated by ELISA, and the spleen cells of the animal with the best titer were selected to be fused with myeloma cells to obtain a parent clone cell strain, with the deposit number of CGMCC NO.18536. In the scope of the disclosure, various well-known cells might be used as myeloma cells, for example, P3, NS-1, P3U1 and SP2/0 derived from mice, YB2/0 and Y3-Ag1 derived from rats, SKO-007 derived from human, and human-mouse hybrid myeloma cell SHM-D33. SP2/0 derived from mice was preferably used in the disclosure.
Then, the parent clone was screened positively and reversely by an ELISA method (an indirect ELISA method was used in both positive and reverse screening experiments).
For a positive screening experiment, the antigen was diluted with a coating buffer (a PBS buffer, pH=7.4) to prepare into an antigen to be coated with a concentration of 1 μg/mL. 100 μL of the antigen to be coated was added to a 96-well plate and incubated at room temperature for 1 hour. The PBS buffer (pH=7.4) was used as a washing solution to remove unreacted antigens. 100 μL of a blocking solution was added to the 96-well plate and incubated at room temperature for 1 hour to block the surface of unreacted solid phases. Excess blocking solution was removed again with the washing solution (the PBS buffer, pH=7.4). Then, 100 μL of a cell supernatant to be screened was added and incubated at room temperature for 30 minutes. An antibody that did not bind to the solid-phase-coated antigen was removed by washing with the washing solution (the PBS buffer, pH=7.4), and then 100 μL of a peroxidase-labeled goat anti-mouse antibody was added. The peroxidase-labeled goat anti-mouse antibody binded to a mouse antibody recognizing the solid phase antigen, and catalyzed the luminescence of a substrate solution. The intensity of the luminescence was used to determine whether there was an antibody that might bind to the antigen in the cell supernatant.
During the antibody screening, the clone screened was confirmed to have no cross-reaction with sCD14 by using sCD14 for reverse screening. For a reverse screening experiment, a His-tag protein and an sCD14 protein were diluted with a coating buffer (a PBS buffer, pH=7.4), respectively to prepare into a substance to be coated with a concentration of 1 μg/mL. The subsequent experimental steps were the same as that of the positive screening experiment. The intensity of the final luminescence value was used to determine whether the antibody in the cell supernatant was reactive with a reverse screening substance.
Subsequent subcloning was performed after screening of the parent clone. Affinity sorting and epitope classification were performed on a subclone. The subclone supernatant was paired with the polyclonal antibody prepared in Step 1.2 to detect the antigen. The results of affinity sorting and epitope classification of the anti-soluble CD14 subtype monoclonal antibody, and of screening of the paired antibody are summarized in Tables 5 to 7. According to the results of affinity sorting and antibody pairing, an antibody with the clone number of 16D5B2 was screened for subsequent production and purification, thereby obtaining a mouse monoclonal antibody.
Step 1.4: Determination of amino acid sequences of an anti-soluble CD14 subtype monoclonal antibody
The variable regions of the anti-soluble CD14 subtype monoclonal antibody obtained from screening in Step 1.3 were sequenced. First, the total RNA of hybridoma cells was extracted according to the instruction manual of TRIzol® kit, and then the total RNA was reverse transcribed into cDNA using an epitope-specific antisense primer or universal primer according to the instruction manual of PrimeScript™ 1st Strand cDNA Synthesis Kit. The corresponding amino acid sequences of the anti-soluble CD14 subtype monoclonal antibody might be obtained by the reverse transcription-synthesized cDNA sequence. The anti-soluble CD14 subtype monoclonal antibody included, for example, VH comprising VH CDR1 composed of the amino acid sequence of SEQ ID NO: 3, VH CDR2 composed of the amino acid sequence of SEQ ID NO: 9 and VH CDR3 composed of the amino acid sequence of SEQ ID NO: 16, and VL comprising VL CDR1 composed of the amino acid sequence of SEQ ID NO: 21, VL CDR2 composed of the amino acid sequence of SEQ ID NO: 29 and VL CDR3 composed of the amino acid sequence of SEQ ID NO: 38, where the anti-soluble CD14 subtype monoclonal antibody specifically recognized an epitope composed of the amino acid sequence of SEQ ID No.42.
In the disclosure, a method for determining an epitope is not particularly defined, for example, it can be carried out in the following manner: firstly, a polypeptide was synthesized by successively moving 3 amino acids from the N-terminus to the C-terminus of the target protein sequence, and each peptide chain consisted of 15 amino acids; then, the polypeptide was labeled with biotin and coated on a 96-well plate containing streptavidin by biotin-streptavidin binding; next, an antibody to be detected and a peroxidase-labeled goat anti-mouse IgG were added to the 96-well plate; the amino acid sequences recognized by the antibody to be detected were determined by the signal value of the final reaction.
It can be seen from the various examples described above that the embodiments of the disclosure may detect a combined signal value of PCT and Presepsin in a sample in a reaction system, the comparison between the combined signal value and a reference value may be used for evaluating the possibility of a patient suffering from sepsis and evaluating the prognosis of a suspected sepsis patient, and compared with detecting PCT or Presepsin in a sample alone, a more efficient diagnosis and a better prognostic power are provided. In addition, for combined detection of PCT and Presepsin in a sample, only one detection is required, so that the economic cost and time cost of the detection may be reduced, the blood consumption may be decreased, and also the effect of reagents of different production batches on the detection results may be reduced, which is conducive to reagent production and instrument automation detection.
The disclosure is not limited to this by the description based on the embodiments. In particular, the disclosure includes each new feature and any combination of the features, especially any combination of features contained in the claims, even if the feature or the combination itself is not specified in detail in the claims or the embodiments.
This application is a Continuation of International Patent Application No. PCT/CN2019/119537, filed on Nov. 19, 2019, the content of each application is hereby incorporated by reference. An electronic version of the Sequence Listing is filed herewith, the contents of which are incorporated by reference in their entirety. The electronic file is 12 kilobytes (KB) in size, and titled IP592_090004-726376_SequenceListing_ST25.txt.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2019/119537 | Nov 2019 | US |
| Child | 17747868 | US |
