This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP2007-061093 filed Mar. 9, 2007, the entire contents of which are hereby incorporated by reference.
The present invention relates to a hematology analyzer for analyzing hemocytes in a blood sample, hematology analyzing method, and a computer program product used in same.
Examples of anemia include iron deficiency anemia (IDA), anemia of chronic disorder (ACD), and megaloblastic anemia (MA) caused by vitamin 12 or folic acid. For example, administration of iron supplement is extremely effective as a treatment for iron deficiency anemia, but not for ACD. The cause of the anemia is therefore important to the treatment of the anemia.
Although examinations for serum iron, serum ferritin, soluble transferrin receptor (sTfR) and the like are performed to manage changes of the iron in the blood (iron dynamics), these examinations present a problem regarding expense.
Administration of recombinant human erythropoietin (rHuEPO) is a widely used treatment for renal anemia. Renal anemia is a disease caused by reduced production and secretion of erythropoietin by the kidney. There are cases treating renal anemia in which not improvement has been obtained despite administration of rHuEPO. The causes for this are various and include functional iron deficiency as a result of administering rHuEPO. The administration of iron supplement in addition to rHuEPO is required in such cases.
Vitamin 12 and folic acid deficiency can obstruct the synthesis of nucleic acid. Red blood cells are rich in folic acid and the most readily influenced, which may lead to megaloblastic anemia.
Since anemia arises from various causes, ascertaining the efficacy of treatment at an early stage is essential. Therefore, attention has been given to methods for checking the occurrence and attributes of reticulocytes. Since reticulocytes are immature red blood cells, monitoring reticulocytes is regarded as promising for treatment of anemia when used an indicator to the status of future hemoglobin production.
For example, U.S. Application No. 2005-219527 discloses a method for calculating the average forward scattered light intensity of mature red blood cells (RBC-Y) and the average forward scattered light intensity of a reticulocyte population (RET-Y) specified in a two-dimensional distribution, calculating the average amount of hemoglobin (RET-He) contained in the reticulocytes based on RET-Y, calculating the average amount of hemoglobin (REC-He) contained in the mature red blood cells based on RBC-Y), and calculating the difference between RET-He and RBC-He (that is, Delta-He).
Although Japanese Laid-Open Patent Publication No. 2005-257450 describes parameters such as average amount of hemoglobin in reticulocytes, average amount of hemoglobin in mature red blood cells, and the difference between the average amounts of hemoglobin of the reticulocytes and mature red blood cells, the relationship between these parameters and any practical clinical use is not disclosed.
The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary.
A first aspect of the present invention is a hematology analyzer comprising: a detecting unit for irradiating a blood sample with light and obtaining optical information which comprises at least scattered light information from each cell contained in the blood sample; a cell classifying means for classifying red blood cells and reticulocytes among the cells based on the obtained optical information; a scattered light information obtaining means for obtaining red blood cell scattered light information which is scattered light information related to red blood cells, and reticulocyte scattered light information which is scattered light information related to reticulocytes based on the classification results of the cell classifying means; a hemoglobin amount obtaining means for obtaining a value equivalent to the amount of hemoglobin in the red blood cells from the red blood cell scattered light information, a value equivalent to the amount of hemoglobin in the reticulocytes from the reticulocyte scattered light information, and difference between the hemoglobin amounts which is the difference between the value equivalent to the amount of hemoglobin in the red blood cells and the value equivalent to the amount of hemoglobin in the reticulocytes; and a supporting information obtaining means for obtaining information supporting clinical examination based on the difference between the hemoglobin amounts and the value equivalent to the amount of hemoglobin in reticulocytes.
A second aspect of the present invention is a hematology analyzing method, comprising steps of: obtaining red blood cell scattered light information which is scattered light information related to red blood cells contained in a blood sample, and reticulocyte scattered light information which is scattered light information related to reticulocytes contained in the blood sample; obtaining a value equivalent to the amount of hemoglobin in the red blood cells from the red blood cell scattered light information; obtaining a value equivalent to the amount of hemoglobin in the reticulocytes from the reticulocyte scattered light information; obtaining difference between the hemoglobin amounts which is the difference between the value equivalent to the amount of hemoglobin in the red blood cells and the value equivalent to the amount of hemoglobin in the reticulocytes; and obtaining information supporting clinical examination based on the value equivalent to the amount of hemoglobin in the reticulocytes and the difference between the hemoglobin amounts.
A third aspect of the present invention is a computer program product, comprising: a computer readable medium; and instructions, on the computer readable medium, adapted to enable a general purpose computer to perform operations, comprising: a step of obtaining red blood cell scattered light information which is scattered light information related to red blood cells contained in a blood sample, and reticulocyte scattered light information which is scattered light information related to reticulocytes contained in the blood sample; a step of obtaining a value equivalent to the amount of hemoglobin in the red blood cells from the red blood cell scattered light information; a step of obtaining a value equivalent to the amount of hemoglobin in the reticulocytes from the reticulocyte scattered light information; a step of obtaining difference between the hemoglobin amounts which is the difference between the value equivalent to the amount of hemoglobin in the red blood cells and the value equivalent to the amount of hemoglobin in the reticulocytes; and a step of obtaining information supporting clinical examination based on the value equivalent to the amount of hemoglobin in the reticulocytes, and the difference between the hemoglobin amounts.
The preferred embodiments of the present invention will be described hereinafter with reference to the drawings.
In the embodiment of the present invention, information which is practically useful for clinical examinations is obtained using the reticulocyte measurement sample. RET SEARCH II, a product supplied by Sysmex Corporation, may be used as the reagent mentioned above which is used for reticulocyte measurements. This reagent is available in a reagent kit which includes dilution solutions and stains; red blood cells, reticulocytes, and platelets are respectively stained by mixing and reacting 900 μl of dilution solution 9 and 18 μl of staining solution in 4.5 μl of blood.
The forward scatter light signal impinging the photomultiplier 46, the side scattered light signal impinging the photomultiplier 4, and the side fluorescent light signal impinging the photomultiplier 52 are detected and photoelectrically converted by the detection units 53, 54, and 55, respectively, and subjected to various types of data processing by the microcomputer 6.
Similar signal detection and data analysis are performed for the other measurement samples in addition to the reticulocyte measurement sample.
As shown in
The microcomputer 6 is provided with a control unit 63 configured by a control processor and a memory for the operation of the control processor, and a data analyzing unit 64 configured by an analysis processor and a memory for the operation of the analysis processor. The control unit 63 controls the actuation of the device 8, which is configured by a sampler (not shown in the drawing) for automatically supplying sample containers, and a fluid supplying system for preparing and measuring samples, and further performs other actuation controls. The data analyzing unit 64 executes analysis processes such as clustering and the like on each of the distribution data. The result of the analysis is sent to the external data processing unit 3 through an interface 65, and external output and the measurement results are processed, such as external output and storage and the like. The microcomputer 6 is further provided with an interface 66 between the microcomputer 6 and the display and operating unit 7, and an interface 67 between the microcomputer 6 and the device 8. The calculation unit 62 control unit 63, and the interfaces 66 and 67 are connected through a bus 68, and the control unit 63, and the data analyzing unit 64 are connected through a bus 69. The display and operating unit 7 includes a start switch with which the operator starts a measurement, and a touch panel type liquid crystal display unit for displaying the status of the apparatus, the various setting values, and analysis results, as well as receiving input from the operator.
First, distribution data of the reticulocyte measurement sample generated by the calculation unit 62 are sent to the data analyzing unit 64 through the buses 63 and 69 (step S1). Clustering is executed on the received distribution data, and each blood cell is classified (step S2).
The description now continues with reference to
RET-He=A×exp(B×RET-Y) Equation 1
(Where A=5.8439 and B=0.0098)
RBC-He=C×exp(D×RBC-Y) Equation 2
(Where C=5.8439 and D=0.0098)
Then, the value (RBC-He) is subtracted from the calculated value (RET-He), and the value (Delta-He), which expresses the difference between the two values, is calculated (step S5).
The manner of deriving these equations is described below.
Equation 2 can be derived by measuring a plurality of samples beforehand using a hematology analyze to obtain the forward scattered light intensity (RBC-Y) and MCH (average amount of hemoglobin) of the mature red blood cells for each sample, plotting the analysis results on a graph with the RBC-Y and MCH as axes, and determining the relationship between RBC-Y and MCH. MCH can be conventionally determined by calculating the amount of hemoglobin calculated by the HGB detection unit 10 and the number of red blood cells calculated by the RBC/PLT detection unit 2 shown in
Although equation 1 has the same format as equation 2 for simplicity, equation 1 may also be obtained by analyzing a plurality of samples beforehand to obtain the amount of hemoglobin contained in reticulocytes and the average forward scattered light intensity (RET-Y) of reticulocytes, plotting the analysis results in a two-dimensional distribution, and determining the relationship between the RET-Y and the amount of hemoglobin contained in reticulocytes from the condition of the distribution of the two-dimensional distribution. The amount of hemoglobin contained in the reticulocytes may be obtained, for example, using ADVIA 120 (Bayer diagnostics, Inc.).
The methods and means for obtaining values which reflect the amount of hemoglobin contained in reticulocytes and mature red blood cells are not limited to the above descriptions inasmuch as such values may also be obtained by other methods and means. For example, such values may also be obtained by detecting and analyzing two forward scattered lights from different angles relative to the axis, and by detecting and analyzing two forward scattered lights of different wavelengths.
The description now returns to
Status identifying information (information supporting clinical examination) corresponding to combined RET-He and Delta-He, which has practical use in clinical examinations, is then derived. One such method uses a region map that utilizes a correlation diagram that has RET-He and Delta-He as parameters.
The clinical meaning of each region is described below.
Region A1 is a region indicating normal hemoglobin synthesis in normally pigmented red blood cells, region A2 is a region indicating normal hemoglobin synthesis in low pigmented red blood cells, region A3 is a region indicating normal hemoglobin synthesis in high pigmented red blood cells, region A4 is a region indicating potential iron deficiency or a functional iron deficiency condition in reaction to inflammation or acute infection, region A5 is a region indicating iron deficiency or functional iron deficiency condition in reaction to acute infection or inflammation, and region A6 also is a region indicating iron deficiency or functional iron deficiency condition in reaction to chronic infection or inflammation similar to region A5. Region A7 is a region indicating elevated hemoglobin synthesis in normal pigmented red blood cells, region A8 is a region indicating elevated hemoglobin synthesis in high pigmented red blood cells, and region A9 is a region indicating elevated hemoglobin synthesis in extremely high pigmented red blood cells.
Described below is the specific process of adding and outputting information supporting clinical examinations which is practical for clinical use using a previously divided region map in the correlation diagram prepared by combining the two values of RET-He and Delta-He, The process is executed by the data analyzing unit 64.
A determination is made as to whether or not the combination of both values belongs to a region on the region map by supplying a sample to the hematology analyzer and applying the RET-He value and the Delta-He value of the sample calculated by the data analyzing unit 64 to the region map read from the memory of the data analyzing unit 64 (step S6). For example, when the calculated values of Delta-He and RET-He are 2 pg, and 27 pg, respectively, the combination of these values falls lies in region A5, the identifying code A5 which corresponds to region A5 (in this instance, the code name is the same as the region name) is appended to the combination of the values, and RET-He and Delta-He are output with other values from the output unit.
In the present embodiment, the values calculated by the data analyzing unit 64 and the corresponding identifying codes are transmitted to the data processing unit 3 through the interface 65, and displayed on the display screen.
In the present embodiment, six distribution maps are displayed in the distribution map display area; reference number 77 refers to a scattergram of a reticulocyte measurement sample in which the forward scattered light intensity is on the vertical axis and the side fluorescent light intensity is on the horizontal axis, and reference number 106 refers to a scattergram in which the scale of the horizontal axis is changed in the scattergram of 77. Reference number 107 refers to a scattergram of a nucleated red blood cell measurement sample in which the forward scattered light intensity is on the vertical axis and the side fluorescent light intensity is on the horizontal axis, and reference number 108 refers to a scattergram in which the scale of the vertical axis is changed in the scattergram of 77. Reference number 78 refers to a histogram of red blood cells, and reference number 79 refers to a histogram of platelets.
The perspective of using the output identifying codes to monitor treatment is described below. In this case the use of the identifying codes is described in monitoring IDA or ACD, and monitoring EPO or iron supplement treatment.
Since iron deficiency anemia expresses small and low pigmented cells, it is usually positioned in region A5. Treatment (medication) begins from this condition. Treatment must be re-evaluated and modified when the values of RET-He and Delta-He calculated after treat has started doe not belong to region A5 or show no effect of treatment. Since a worsening of the anemia is indicated if the values move from region A5 to region A4, the treatment must be re-evaluated. If the values move from region A5 to region A6, the treatment must be continued or modified since partial treatment success is suggested. If the values move from region A6 to region A2, treatment effectiveness is definitely evidenced, and an ultimate move to region A1 can be anticipated.
Monitoring treatment of vitamin B12 or folic acid is described below. Megaloblastic anemia expresses large and high pigmented cells, it usually is positioned in region A7 or A8. The treatment must be regarded as ineffective if the values of RET-He and Delta-He fall in region A 7 or A8 after treatment has been started. If the values move from region A7 or A8 to region A3, the treatment is confirmed to be effective. If this condition continues, the values can be expected to shift to region A1.
An example of the status identifying information (information supporting clinical examination) output is described below.
The display screen and keyboard of the data processing unit 3 are first operated to select and start the graph display menu to monitor anemia (step S11). One or more samples on the graph display are selected from a list of stored samples (step S12), and confirmed (step S13). The stored sample is stored on the hard disk of the data processing unit 3, and blood analysis results of each patient as well as patient attribute information are associated and stored. Processing for the graph display of the selected sample is performed by the data processing unit 3 (step S14), and a correlation diagram divided in to region is displayed on the display screen of the data processing unit 3.
The degree of severity of the anemia and the treatment efficacy can be clearly recognized and grasped visually by outputting a correlation diagram which plots the RET-He and Delta-He data together with the divided regions.
Although red blood cells and reticulocytes are classified using scattered light information and fluorescent light information as optical information in the present embodiment, the present invention is not limited to this arrangement inasmuch as red blood cells and reticulocytes may also be classified, for example, using scattered light information and cell light absorption information.
Although the output of a correlation diagram is described in the above embodiment, the present invention is not limited to this arrangement inasmuch as, for example, a clinical meaning may be output which corresponds to the region in which analysis results are plotted. That is, a summary indicating the patient has normal hemoglobin synthesis in normal pigmented red blood cells may be output when the analysis results are plotted region A1 of the region map shown in
Although the analysis program for obtaining status identifying information (information supporting clinical examination) is installed beforehand in the data analyzing unit 64 in the above embodiment, the program need not be provided beforehand in the hematology analyzer inasmuch as the analysis program may be provided as a computer program that can realize the functions of the present invention by installing the computer program on a conventional hematology analyzer.
Number | Date | Country | Kind |
---|---|---|---|
2007-061093 | Mar 2007 | JP | national |