This disclosure concerns a viral exposure signature and its use for identifying a subject with early stage (pre-symptomatic) hepatocellular carcinoma.
Hepatocellular carcinoma (HCC) is considered a virus-related malignancy in which hepatitis B and C viruses (HCV and HBV) are major etiological factors (Farazi et al., Nat Rev Cancer 2006; 6:674-687). Viral hepatitis causes inflammation and chronic liver diseases (CLD), which may lead to fibrosis, cirrhosis and eventually, HCC. While HBV or HCV chronic carriers have an increased risk of developing HCC, the risk varies among individuals and not all patients with liver disease develop liver cancer (Arzumanyan et al., Nat Rev Cancer 2013; 13:123-135). An effective strategy to prevent HCC is to eliminate causative factors. However, while direct-acting antiviral (DDA) treatment is remarkably effective in eliminating HCV infection, it reduces but does not completely eliminate HCC risk (Janjua et al., J Hepatol 2017; 66:504-513; Carrat et al., Lancet 2019; 393:1453-1464). Similarly, HBV vaccination, introduced in the early 80s, has been successful in significantly reducing HBV carriers but only modestly reduces HCC burden in HBV-prevalent areas (Chang et al., Gastroenterology 2016; 151:472-480). It is puzzling that the control of HBV infection in HBV-prevalent areas as well as HCV infection has been remarkably successful for decades, while the global HCC incidence and mortality rate has continued to increase since the 1990s (Liu et al., J Hepatol 2019; 70:674-683). Changing trends of etiological factors such as alcohol and non-alcohol/non-viral related liver diseases may contribute to the observed increase. Thus, in addition to cancer prevention, early detection is a key research area to stop HCC-inflicted mortality. Currently, medical guidelines recommend biannual surveillance using ultrasound with or without alpha-fetoprotein (AFP) for individuals with chronic liver disease such as cirrhosis (Sherman et al., Hepatology 2012; 56:793-796). However, these practices have yielded mix results as to whether it is effective in detecting HCC at an early stage and can provide survival benefit (Tzartzeva et al., Gastroenterology 2018; 154:1706-1718; Moon et al., Gastroenterology 2018; 155:1128-1139; Sherman et al., Hepatology 1995; 22:432-438). Noticeably, a majority of HCC patients are still diagnosed at an advanced stage, which precludes their chance to receive potentially curative therapies, and consequently leads to poor survival. Thus, there is an unmet need to implement an effective biomarker-guided surveillance program for early cancer detection.
Described herein is a viral exposure signature (VES) that can be used to identify a subject with early stage HCC, particularly pre-symptomatic HCC. The VES is based on the presence or absence of antibodies to specific viral strains in a subject. Detection of the VES in a subject can be used, for example, to guide treatment and disease monitoring decisions.
Provided herein are methods of identifying a subject with early stage HCC. In some embodiments, the method includes detecting the presence or absence of antibodies to a plurality of viruses in a sample obtained from the subject; determining the presence of a viral exposure signature (VES) in the sample obtained from the subject; and identifying the subject as being at risk for developing HCC when the VES is present. In some embodiments, the plurality of viruses comprises at least 10, at least 20, at least 30, at least 40, at least 50 or at least 60 of the viruses listed in Table 5A. In some examples, the plurality of viruses comprises or consists of the 61 viruses listed in Table 5A or the 31 viruses listed in Table 6.
In some embodiments, the presence of the VES is determined by identifying antibodies to one or more of hepatitis C virus (HCV) genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; human cytomegalovirus, strain AD169; HCV genotype 6g, isolate JK046; HCV genotype 1b, isolate BK; HCV genotype 1c, isolate HC-G9; HCV genotype 1b, strain HC-J4; HCV genotype 4a, isolate ED43; hepatitis delta virus; HCV genotype 5a, isolate EUH1480; human cytomegalovirus; Crimean-Congo hemorrhagic fever virus, strain Nigeria/IbAr10200/1970; HCV genotype 1b, isolate HC-J1; influenza A virus, strain A/USSR/90/1977 H1N1; influenza A virus, strain A/Bangkok/1/1979 H3N2; HCV genotype 1c, isolate India; and Chapare virus, isolate Human/Bolivia/810419/2003.
In some embodiments, the presence of the VES is determined by not detecting antibodies to one or more of Epstein-Barr virus, strain B95-8; human rhinovirus 23; HCMV, strain Towne; human herpesvirus 2 (HHV-2), strain HG52; human herpesvirus 3; varicella-zoster virus, strain Dumas; Cercopithecine herpesvirus 16; human adenovirus C serotype 2; human astrovirus-1; human respiratory syncytial virus; human herpesvirus 6B, strain Z29; human herpesvirus 7, strain JI; human rhinovirus 14; Lordsdale virus, strain GII/Human/United Kingdom/Lordsdale/1993; human herpesvirus 1, strain KOS; human metapneumovirus, strain CAN97-83; coxsackievirus A16, strain G-10; Epstein-Barr virus, strain AG876; cowpox virus; human herpesvirus 1, strain 17; human adenovirus E serotype 4; human adenovirus F serotype 40; tanapox virus; human adenovirus C serotype 5; rhinovirus B; human herpesvirus 8; human herpesvirus 6A, strain Uganda-1102; human rhinovirus A serotype 89, strain 41467-Gallo; norovirus MD145, isolate GII/Human/United States/MD145-12/1987; molluscum contagiosum virus subtype 1; vaccinia virus, strain Copenhagen; poliovirus type 1, strain Sabin; orf virus; HHV-2, strain 333; hepatitis B virus; Epstein-Barr virus, strain GD1; human parainfluenza 3 virus, strain Wash/47885/57; HHV-2; human enterovirus 71, strain BrCr; human herpesvirus 6A, strain GS; Cercopithecine herpesvirus 1; influenza B virus, strain B/Yamagata/16/1988; and influenza A virus, strain A/Philippines/2/1982 H3N2.
In other embodiments, the method of identifying a subject with early stage HCC includes (i) detecting the presence or absence of antibodies specific for a plurality of viruses in a sample obtained from the subject, wherein the plurality of viruses comprises hepatitis C virus (HCV) genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; human cytomegalovirus (HCMV) strain AD169; HCV genotype 6g, isolate JK046; Epstein-Barr virus (EBV), strain B95-8; human rhinovirus 23; HCMV strain Towne; HCV genotype 1b, isolate BK; and human herpesvirus 2 (HHV-2), strain HG52; and (ii) identifying the subject as being at risk for developing HCC if: (a) antibodies specific for HCV genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; HCMV strain AD169; HCV genotype 6g, isolate JK046; and/or HCV genotype 1b, isolate BK, are detected in the sample; and/or (b) antibodies specific for EBV, strain B95-8; human rhinovirus 23; HCMV strain Towne; and/or HHV-2, strain HG52, are not detected in the sample.
In some embodiments, the sample is a blood or serum sample.
In some embodiments, the antibodies are detected by phage immunoprecipitation, immunoblot or enzyme-linked immunosorbent assay.
In some embodiments, the method further includes administering an appropriate therapy or providing an appropriate procedure (such as surgery) for the treatment of HCC. In some examples, the method further includes performing a liver transplant in the subject with early stage HCC. In other examples, the method further includes liver resection of the subject with early stage HCC, with or without radiofrequency ablation (RFA). In some examples, if the subject is also positive for HBV or HCV, the subject is administered an anti-viral drug.
In some embodiments, the method further includes active diagnostic monitoring of the subject with early stage HCC. For example, the subject can be monitored on a regular schedule, such as every 3 months or every 6 months, using ultrasound, contrast enhanced computerized tomography (CT) and/or magnetic resonance imaging (MRI).
Also provided is a phage display library expressing unique peptide epitopes from each of the viruses listed in Table 5A or Table 6. In some embodiments, the phage display library expresses the peptides of SEQ ID NOs: 1-61, or a subset thereof. In some examples, the phage display library expresses the peptides of SEQ ID NOs: 1-102, or a subset thereof. In other examples, the phage display library expresses the peptides of SEQ ID NOs: 62-102, or a subset thereof.
Further provided is an array comprising unique peptide epitopes from each of the viruses listed in Table 5A or Table 6. In some examples the unique peptide epitopes comprise the peptides of SEQ ID NOs: 1-61 (shown in Table 5B), the peptides of SEQ ID NOs: 62-102 (shown in Table 3B), or the peptides of SEQ ID NOs: 1-102.
The foregoing and other objects and features of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
The amino acid sequences listed in the accompanying sequence listing are shown using standard three letter code for amino acids, as defined in 37 C.F.R. 1.822. The Sequence Listing is submitted as an ASCII text file, created on Oct. 8, 2020, 58.3 KB, which is incorporated by reference herein. In the accompanying sequence listing:
SEQ ID NOs: 1-102 are amino acid sequences of unique peptide epitopes from human viruses.
Unless otherwise noted, technical terms are used according to conventional usage. Definitions of common terms in molecular biology may be found in Benjamin Lewin, Genes VII, published by Oxford University Press, 2000 (ISBN 019879276X); Kendrew et al. (eds.), The Encyclopedia of Molecular Biology, published by Blackwell Publishers, 1994 (ISBN 0632021829); Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by Wiley, John & Sons, Inc., 1995 (ISBN 0471186341); and George P. Rédei, Encyclopedic Dictionary of Genetics, Genomics, and Proteomics, 2nd Edition, 2003 (ISBN: 0-471-26821-6).
The singular forms “a,” “an,” and “the” refer to one or more than one, unless the context clearly dictates otherwise. For example, the term “comprising a probe” includes single or plural probes and is considered equivalent to the phrase “comprising at least one probe.” The term “or” refers to a single element of stated alternative elements or a combination of two or more elements, unless the context clearly indicates otherwise. As used herein, “comprises” means “includes.” Thus, “comprising A or B,” means “including A, B, or A and B,” without excluding additional elements.
Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety, as are the GenBank® Accession numbers (for the sequence present on Feb. 8, 2016). In case of conflict, the present specification, including explanations of terms, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
Except as otherwise noted, the methods and techniques of the present disclosure are generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification. See, e.g., Sambrook et al., Molecular Cloning: A Laboratory Manual, 2d ed., Cold Spring Harbor Laboratory Press, 1989; Sambrook et al., Molecular Cloning: A Laboratory Manual, 3d ed., Cold Spring Harbor Press, 2001; Ausubel et al., Current Protocols in Molecular Biology, Greene Publishing Associates, 1992 (and Supplements to 2000); Ausubel et al., Short Protocols in Molecular Biology: A Compendium of Methods from Current Protocols in Molecular Biology, 4th ed., Wiley & Sons, 1999; Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 1990; and Harlow and Lane, Using Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 1999.
In order to facilitate review of the various embodiments of the disclosure, the following explanations of specific terms are provided:
Administration: The introduction of an agent, such as an anti-viral therapeutic, into a subject by a chosen route. Administration can be local or systemic. For example, if the chosen route is intravascular, the agent is administered by introducing the composition into a blood vessel of the subject. Exemplary routes of administration include, but are not limited to, oral, injection (such as subcutaneous, intramuscular, intradermal, intraperitoneal, and intravenous), sublingual, rectal, transdermal (for example, topical), intranasal, vaginal, and inhalation routes.
Antibody: A polypeptide ligand comprising at least one variable region that recognizes and binds (such as specifically recognizes and specifically binds) an epitope of an antigen, such as a viral antigen. Mammalian immunoglobulin molecules are composed of a heavy (H) chain and a light (L) chain, each of which has a variable region, termed the variable heavy (VH) region and the variable light (VL) region, respectively. Together, the VH region and the VL region are responsible for binding the antigen recognized by the antibody. There are five main heavy chain classes (or isotypes) of mammalian immunoglobulin, which determine the functional activity of an antibody molecule: IgM, IgD, IgG, IgA and IgE. Antibody isotypes not found in mammals include IgX, IgY, IgW and IgNAR. IgY is the primary antibody produced by birds and reptiles, and has some functionally similar to mammalian IgG and IgE. IgW and IgNAR antibodies are produced by cartilaginous fish, while IgX antibodies are found in amphibians.
Array: An arrangement of molecules, such as biological macromolecules (such as peptides or nucleic acid molecules) or biological samples (such as tissue sections), in addressable locations on or in a substrate. In some embodiments herein, the array comprises at least 10, at least 20, at least 30, at least 40, at least 50, at least 60 (such as 61) addressable locations. In particular examples, the array comprises peptide epitopes from each of the viruses listed in Table 5A or Table 6.
Control: A “control” refers to a sample or standard used for comparison with an experimental sample, such as a serum sample obtained from a subject suspected of having or at risk for HCC. In some embodiments, the control is a sample obtained from a healthy patient (e.g., one not having HCC or cirrhosis). In some embodiments, the control is a historical control or standard reference value or range of values (e.g., a previously tested control sample, such as a group of samples that represent baseline or normal values).
Diagnosis: The process of identifying a disease by its signs, symptoms and results of various tests. The conclusion reached through that process is also called “a diagnosis.” Forms of testing commonly performed include blood tests, medical imaging, and biopsy.
Early stage: In the context of the present disclosure, detecting “early stage” HCC refers to identifying HCC in a subject prior to the onset of symptoms and/or prior to standard clinical diagnosis. “Early stage” in this context is not synonymous with stage 0 or stage I cancer. In some embodiments, early stage HCC is characterized by the presence of a single lesion less than 3 cm in diameter (such as 0.1 to 2.9 cm in diameter, such as 0.5 to 2.5 cm, 0.5 to 1 cm or 1 to 2.9 cm in dimeter) without detectable local or distant metastatic lesions (such as detectable by CT or MRI).
Epitope: An antigenic determinant. These are particular chemical groups or peptide sequences on a molecule that are antigenic, i.e. that elicit a specific immune response. An antibody specifically binds a particular antigenic epitope on a polypeptide, such as a viral polypeptide.
Hepatocellular carcinoma (HCC): A primary malignancy of the liver, which in some cases occurs in patients with inflammatory livers resulting from viral hepatitis, liver toxins or hepatic cirrhosis (often caused by alcoholism). Exemplary therapies for HCC include but are not limited to, one or more of surgery, transarterial chemoembolization (TACE), ablative therapies (including both thermal and cryoablation), radio embolization, and percutaneous alcohol injection.
Isolated: An “isolated” biological component (such as a nucleic acid molecule, protein, or cell) has been substantially separated or purified away from other biological components, such as other chromosomal and extra-chromosomal DNA and RNA, proteins and cells. Nucleic acid molecules and proteins that have been “isolated” include nucleic acid molecules and proteins purified by standard purification methods. The term also embraces nucleic acid molecules and proteins prepared by recombinant expression in a host cell as well as chemically synthesized nucleic acid molecules and proteins.
Sample (or biological sample): A biological specimen containing genomic DNA, RNA (including mRNA), protein (such as antibodies), or combinations thereof, obtained from a subject. Examples include, but are not limited to, peripheral blood, plasma, urine, saliva, tissue biopsy, fine needle aspirate, punch biopsy surgical specimen, and autopsy material. In specific embodiments herein, the sample is a blood or serum sample.
Sequence identity: The identity or similarity between two or more nucleic acid sequences, or two or more amino acid sequences, is expressed in terms of the identity or similarity between the sequences. Sequence identity can be measured in terms of percentage identity; the higher the percentage, the more identical the sequences are. Sequence similarity can be measured in terms of percentage similarity (which takes into account conservative amino acid substitutions); the higher the percentage, the more similar the sequences are.
Methods of alignment of sequences for comparison are well known in the art. Various programs and alignment algorithms are described in: Smith & Waterman, Adv. Appl. Math. 2:482, 1981; Needleman & Wunsch, J. Mol. Biol. 48:443, 1970; Pearson & Lipman, Proc. Natl. Acad. Sci. USA 85:2444, 1988; Higgins & Sharp, Gene, 73:237-44, 1988; Higgins & Sharp, CABIOS 5:151-3, 1989; Corpet et al., Nuc. Acids Res. 16:10881-90, 1988; Huang et al. Computer Appls. in the Biosciences 8, 155-65, 1992; and Pearson et al., Meth. Mol. Bio. 24:307-31, 1994. Altschul et al., J. Mol. Biol. 215:403-10, 1990, presents a detailed consideration of sequence alignment methods and homology calculations.
The NCBI Basic Local Alignment Search Tool (BLAST) (Altschul et al., J. Mol. Biol. 215:403-10, 1990) is available from several sources, including the National Center for Biological Information (NCBI) and on the internet, for use in connection with the sequence analysis programs blastp, blastn, blastx, tblastn and tblastx. Additional information can be found at the NCBI web site.
Subject: Living multi-cellular vertebrate organisms, a category that includes human and non-human mammals. In some examples herein, the subject is suspected of having or at risk for having HCC.
Tumor: All neoplastic cell growth and proliferation, whether malignant or benign, and all pre-cancerous and cancerous cells and tissues. In some examples, the tumor is a HCC tumor.
Viruses are known to affect human health by altering host immunity, which makes the interplay between the virome and the host crucial in the pathogenesis of human chronic diseases, including cancer (Foxman et al., Nat Rev Microbiol 2011; 9:254-64; Cadwell, Immunity 2015; 42:805-813). Diverse pathogenic and non-pathogenic viruses may interact with one another as well as their host to shape host immunity, which may alter its response to new infections. Consequently, viruses that persist or are cleared in the host may leave unique molecular footprints that can alter disease susceptibility to cancer and may serve as an excellent window of early onset disease (Cadwell, Immunity 2015; 42:805-813). It was hypothesized that unique post-viral exposure signatures resulting from virus-host interactions could reflect a cascade of events that may alter the risk of developing HCC. Such signatures could serve as early detection biomarkers and offer knowledge about potentially modifiable factors for early onset HCC. In the study disclosed herein, serological samples from 899 individuals enrolled in a case-control study of liver cancer (NCT00913757; clinicaltrials.gov) were profiled using a synthetic virome technology, VirScan, based on a high-throughput sequencing method, to detect exposure history to all known human viruses (Xu et al., Science 2015; 348:aaa0698). A unique viral exposure signature (VES) that can discriminate HCC cases from CLD and healthy volunteers matched by age and sex is disclosed herein. The VES was validated in a prospective National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at-risk cohort for HCC.
Provided herein are methods of identifying a subject as being at risk for developing HCC. In some embodiments, the method includes detecting the presence or absence of antibodies to a plurality of viruses in a sample obtained from the subject; determining the presence of a viral exposure signature (VES) in the sample obtained from the subject; and identifying the subject as being at risk for developing HCC when the VES is present.
In some embodiments, the presence of the VES is determined by identifying antibodies to one or more of hepatitis C virus (HCV) genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; human cytomegalovirus, strain AD169; HCV genotype 6g, isolate JK046; HCV genotype 1b, isolate BK; HCV genotype 1c, isolate HC-G9; HCV genotype 1b, strain HC-J4; HCV genotype 4a, isolate ED43; hepatitis delta virus; HCV genotype 5a, isolate EUH1480; human cytomegalovirus; Crimean-Congo hemorrhagic fever virus, strain Nigeria/IbAr10200/1970; HCV genotype 1b, isolate HC-J1; influenza A virus, strain A/USSR/90/1977 H1N1; influenza A virus, strain A/Bangkok/1/1979 H3N2; HCV genotype 1c, isolate India; and Chapare virus, isolate Human/Bolivia/810419/2003.
In some embodiments, the presence of the VES is determined by not detecting antibodies to one or more of Epstein-Barr virus, strain B95-8; human rhinovirus 23; HCMV, strain Towne; human herpesvirus 2 (HHV-2), strain HG52; human herpesvirus 3; varicella-zoster virus, strain Dumas; Cercopithecine herpesvirus 16; human adenovirus C serotype 2; human astrovirus-1; human respiratory syncytial virus; human herpesvirus 6B, strain Z29; human herpesvirus 7, strain JI; human rhinovirus 14; Lordsdale virus, strain GII/Human/United Kingdom/Lordsdale/1993; human herpesvirus 1, strain KOS; human metapneumovirus, strain CAN97-83; coxsackievirus A16, strain G-10; Epstein-Barr virus, strain AG876; cowpox virus; human herpesvirus 1, strain 17; human adenovirus E serotype 4; human adenovirus F serotype 40; tanapox virus; human adenovirus C serotype 5; rhinovirus B; human herpesvirus 8; human herpesvirus 6A, strain Uganda-1102; human rhinovirus A serotype 89, strain 41467-Gallo; norovirus MD145, isolate GII/Human/United States/MD145-12/1987; molluscum contagiosum virus subtype 1; vaccinia virus, strain Copenhagen; poliovirus type 1, strain Sabin; orf virus; HHV-2, strain 333; hepatitis B virus; Epstein-Barr virus, strain GD1; human parainfluenza 3 virus, strain Wash/47885/57; HHV-2; human enterovirus 71, strain BrCr; human herpesvirus 6A, strain GS; Cercopithecine herpesvirus 1; influenza B virus, strain B/Yamagata/16/1988; and influenza A virus, strain A/Philippines/2/1982 H3N2.
In some embodiments, the plurality of viruses includes at least 10, at least 20, at least 30, at least 40, at least 50 or at least 60 of the viruses listed in Table 5A. In some examples, the plurality of viruses comprises or consists of the 61 viruses listed in Table 5A. In some examples, the plurality of viruses comprises or consists of the 31 viruses listed in Table 6.
In particular embodiments, step (ii) includes determining the presence of the VES in the sample obtained from the subject if (a) antibodies specific for three or more, four or more, five or more, six or more, or seven or more of hepatitis C virus (HCV) genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; human cytomegalovirus, strain AD169; HCV genotype 6g, isolate JK046; HCV genotype 1b, isolate BK; HCV genotype 1c, isolate HC-G9; HCV genotype 1b, strain HC-J4; HCV genotype 4a, isolate ED43; hepatitis delta virus; HCV genotype 5a, isolate EUH1480; human cytomegalovirus; Crimean-Congo hemorrhagic fever virus, strain Nigeria/IbAr10200/1970; HCV genotype 1b, isolate HC-J1; influenza A virus, strain A/USSR/90/1977 H1N1; influenza A virus, strain A/Bangkok/1/1979 H3N2; HCV genotype 1c, isolate India; and Chapare virus, isolate Human/Bolivia/810419/2003 are detected in the sample; and/or (b) antibodies specific for three or more, four or more, five or more, six or more, or seven or more of Epstein-Barr virus, strain B95-8; human rhinovirus 23; HCMV, strain Towne; human herpesvirus 2 (HHV-2), strain HG52; human herpesvirus 3; varicella-zoster virus, strain Dumas; Cercopithecine herpesvirus 16; human adenovirus C serotype 2; human astrovirus-1; human respiratory syncytial virus; human herpesvirus 6B, strain Z29; human herpesvirus 7, strain JI; human rhinovirus 14; Lordsdale virus, strain GII/Human/United Kingdom/Lordsdale/1993; human herpesvirus 1, strain KOS; human metapneumovirus, strain CAN97-83; coxsackievirus A16, strain G-10; Epstein-Barr virus, strain AG876; cowpox virus; human herpesvirus 1, strain 17; human adenovirus E serotype 4; human adenovirus F serotype 40; tanapox virus; human adenovirus C serotype 5; rhinovirus B; human herpesvirus 8; human herpesvirus 6A, strain Uganda-1102; human rhinovirus A serotype 89, strain 41467-Gallo; norovirus MD145, isolate GII/Human/United States/MD145-12/1987; molluscum contagiosum virus subtype 1; vaccinia virus, strain Copenhagen; poliovirus type 1, strain Sabin; orf virus; HHV-2, strain 333; hepatitis B virus; Epstein-Barr virus, strain GD1; human parainfluenza 3 virus, strain Wash/47885/57; HHV-2; human enterovirus 71, strain BrCr; human herpesvirus 6A, strain GS; Cercopithecine herpesvirus 1; influenza B virus, strain B/Yamagata/16/1988; and influenza A virus, strain A/Philippines/2/1982 H3N2 are not detected in the sample.
In some embodiments, the sample is a blood or serum sample. In some examples, the method further includes obtaining the biological sample from the subject. In some examples, the subject is a human subject.
The presence of antibodies can be detected using any immunoassay. In some embodiments, the antibodies are detected by phage immunoprecipitation, immunoblot or enzyme-linked immunosorbent assay.
Also provided is a phage display library expressing unique peptide epitopes from each of the viruses listed in Table 5A or Table 6. The phage display library can be used to determine the presence of the VES. In some embodiments, the phage display library expresses the peptides of SEQ ID NOs: 1-61 (see Table 5B). In other examples, the phage display library expresses the peptides of SEQ ID NOs: 62-102 (see Table 3B). In some examples, the phage display library expresses the peptides of SEQ ID NOs: 1-102. In some examples, the phage display library expresses peptides at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identical to any of SEQ ID NOs: 1-61, SEQ ID NOs: 62-102 and SEQ ID NOs: 1-102.
Further provided is an array including unique peptide epitopes from each of the viruses listed in Table 5A or Table 6. The array can be used to determine the presence of the VES. In some examples the unique peptide epitopes comprise the peptides of SEQ ID NOs: 1-61 (shown in Table 5B), the peptides of SEQ ID NOs: 62-102 (shown in Table 3B), or the peptides of SEQ ID NOs: 1-102. In some examples, the peptides have amino acid sequences at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identical to any of SEQ ID NOs: 1-61, SEQ ID NOs: 62-102 and SEQ ID NOs: 1-102.
In other embodiments provided herein, the method of identifying a subject as being at risk for developing HCC includes (i) detecting the presence or absence of antibodies specific for a plurality of viruses in a sample obtained from the subject, wherein the plurality of viruses includes hepatitis C virus (HCV) genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; human cytomegalovirus (HCMV) strain AD169; HCV genotype 6g, isolate JK046; Epstein-Barr virus (EBV), strain B95-8; human rhinovirus 23; HCMV strain Towne; HCV genotype 1b, isolate BK; and human herpesvirus 2 (HHV-2), strain HG52; and (ii) identifying the subject as being at risk for developing HCC if: (a) antibodies specific for HCV genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; HCMV strain AD169; HCV genotype 6g, isolate JK046; and/or HCV genotype 1b, isolate BK, are detected in the sample; and/or (b) antibodies specific for EBV, strain B95-8; human rhinovirus 23; HCMV strain Towne; and/or HHV-2, strain HG52, are not detected in the sample.
In some examples, step (ii) includes identifying the subject as being at risk for developing HCC if (a) antibodies specific for at least two, at least three, at least four, at least five or all six of HCV genotype 3b, isolate Tr-Kj; HCV genotype 1b, isolate Taiwan; HCV genotype 1a, isolate 1; HCMV strain AD169; HCV genotype 6g, isolate JK046; and HCV genotype 1b, isolate BK, are detected in the sample; and/or (b) antibodies specific for at least one, at least two, at least three or all four of EBV strain B95-8; human rhinovirus 23; HCMV strain Towne; and/or HHV-2 strain HG52, are not detected in the sample.
In some examples, the sample is a blood or serum sample. In specific examples, the method further includes obtaining the biological sample from the subject.
In some examples, the antibodies are detected by phage immunoprecipitation, immunoblot or enzyme-linked immunosorbent assay.
In some embodiments of the disclosed methods, the method further includes treating a subject with an appropriate therapy to aid in the prevention or treatment of HCC. In some examples, the appropriate therapy includes vaccination against hepatitis B virus (HBV) (such as administration of Engerix-B®, Recombivax HB®, or Heplisav-B®), anti-viral treatment against HBV (such as administration of PEG-IFN, entecavir, tenofovir, lamivudine, adefovir, and/or telbivudine) and/or anti-viral treatment against HCV (such as administration of one or more of glecaprevir, sofobuvir, daclatasvir, grazoprevir, and ombitasvir). Anti-viral drugs include, for example, nucleoside/nucleotide analogs (e.g., entecavir and tenofovir disoproxil fumarate), interferon, and lamivudine. In some examples, the method further includes performing a liver transplant in the subject with early stage HCC. In other examples, the method further includes liver resection of the subject with early stage HCC, with or without radiofrequency ablation (RFA).
In some embodiments, the method further includes active diagnostic monitoring of the subject with early stage HCC. For example, the subject can be monitored on a regular schedule, such as every 2 months, every 3 months, every 4 months, every 5 months or every 6 months, using ultrasound, contrast enhanced computerized tomography (CT) and/or magnetic resonance imaging (MRI).
In some examples, the additional treatment includes lifestyle or diet changes, including programs to reduce intravenous drug use, needle exchange programs, prevention of sexually-transmitted diseases, reducing or eliminating alcohol consumption, reducing obesity-related inflammation (such as by improving diet and increasing exercise), improving insulin resistance, increasing consumption of vegetables, consuming branched-chain amino acids and/or taking vitamin D. For some patients, such as those with hereditary hemochromatosis, iron overload can increase the risk of developing HCC. Thus, in some examples, the appropriate therapy includes treating iron overload. Aflatoxin B1, a known carcinogen produced by fungi of the Aspergillus species, is commonly found as a contaminate of grains, nuts, and vegetables in regions such as Asia and Africa. Thus, reducing aflatoxin exposure can also be used to prevent or treat HCC. Additional preventative therapies and treatments are described in Schutte et al., Gastrointest Tumors 3(1): 37-43, 2016 and Schutte et al., Gastrointest Tumors 2(4): 188-194, 2016.
In some embodiments of the present disclosure, the methods of detecting the presence or absence of specific antibodies in patient samples, and thereby determining the presence of the VES, can be performed using phage immunoprecipitation sequencing (PhIP-Seq). This method is a high-throughput method that allows for a comprehensive analysis of a subject's antibody repertoire (see U.S. Publication No. 2016/0320406; Larman et al., Nat. Biotechnol 29: 535-541, 2011; and Mohan et al., Nat Protoc 13:1958-1978, 2018; each of which is incorporated by reference herein).
PhIP-Seq is one method that can be used to rapidly detect the presence or absence of a plurality of virus-specific antibodies in a patient sample. Briefly, this method includes designing a peptide library that is representative of the viruses that are to be detected. In context of the present disclosure, the library includes, for example, the 61 or 31 unique peptide epitopes of the 61-VES or 31-VES, respectively (see Tables 5A and 6). An oligonucleotide library encoding the peptides is constructed and PCR-amplified with adapters for cloning into a selected phage display vector to produce the phage display library. A patient sample, such as a blood or serum sample, is contacted with the phage display library to allow for phage-antibody complex formation and subsequent immunoprecipitation. The library of peptide-encoding oligonucleotide sequences is amplified by PCR directly from the immunoprecipitate, bar-coded and subjected to deep sequencing. Additional details of this method can be found in U.S. Publication No. 2016/0320406; Larman et al. (Nat. Biotechnol 29: 535-541, 2011), Mohan et al. (Nat Protoc 13:1958-1978, 2018), and the Novagen T7Select System Manual (available online)
The following examples are provided to illustrate certain particular features and/or embodiments. These examples should not be construed to limit the disclosure to the particular features or embodiments described.
This example describes the materials and experimental procedures used for the studies described in Example 2.
The patient cohort consisted of 899 sequentially enrolled participants (clinicaltrials.gov number: NCT0091375), including 150 HCC cases, 337 CLD as at-risk individuals (HR or AR, used interchangeably) and 412 healthy volunteers as a population control (PC) matched by age and sex (
UMD cohort. To measure virome-host interplay, 899 participants were recruited. Participants were grouped as (1) population control (PC, n=412) if they were relatively healthy without any diagnosis of liver disease; (2) high-risk (HR, n=337) if they were diagnosed with chronic liver diseases (hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis delta virus (HDV), aflatoxins from fungal contamination, alcohol, nonalcoholic fatty-liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH)); or hepatocellular carcinoma (HCC, n=150) if they were diagnosed with HCC. All clinic measurements were covered by NCT0091375 (clinicaltrials.gov) with the enrollment criteria as the liver disease status. Serum, matching buffy coat and cheek swab samples were collected from each individual.
NIDDK cohort. This cohort consisted of 173 patients with chronic liver disease that included 44 HCC cases with 129 controls matched by liver disease etiology, age and sex. Patients were enrolled in a natural history protocol (clinicaltrials.gov number; NCT0001971) with longitudinal follow-up, at least annually with serologic testing and imaging, for up to 20 years. Only cases with complete clinical and laboratory data and available longitudinal serologic samples were selected for analysis. The 44 HCC cases were sequentially identified out of 3,067 patients followed in this natural history study on chronic liver disease, and the controls were matched on a 2:1 basis as described above. HCC was diagnosed by radiologic imaging and/or liver biopsy as described by the American Association for the Study of Liver Disease (AASLD) practice guidelines (see Marrero et al., “Diagnosis, Staging and Management of Hepatocellular Carcinoma: 2018 Practice Guidance by the American Association for the Study of Liver Diseases,” Hepatology 68(2): 723-750, 2018). For the purposes of this analysis, stored serum samples (−80° C.) were analyzed at study entry (baseline) and at recurrent time points until the time of HCC diagnosis.
Blood samples were collected and stored at −80° C. (n=899 from UMD, n=488 from NIDDK). Buffy coat and cheek swab samples also were collected and stored at −80° C. (n=849 from UMD).
Phage immunoprecipitation and sequencing were performed using a slightly modified version of previously published PhIP-Seq protocols. First, 96-deep-well plates were blocked with bovine serum albumin in TBST overnight on a rotator at 4° C. The diluted 1 ml bacteriophage library was added in each blocked well. Serum samples, containing 2 mg IgG, were mixed with the bacteriophage library. Two technical replicates for each sample were set up. After an overnight rotation, protein A and protein G Dynabeads were added to each well. After another 4-hour incubation on a rotator at 4° C. with a 96-well magnetic stand, the beads were washed three times with 400 ml of PhIP-Seq wash buffer. Next, the beads were resuspended in water and lysed at 95° C. for 10 minutes. Blank PBS samples (instead of serum) were also set up as negative controls on each plate. Two rounds of PCR were performed to amplify and multiplex on the lysed bacteriophage DNA product. After the second round of PCR, PCR products were pooled using equimolar amounts of all 192 samples for gel extraction. After gel extraction, the size and quality of libraries were assessed on a Bioanalyzer instrument from Agilent. The DNA samples were aliquoted and stored at −80° C. until sequencing. Sequencing was performed using 50 bp single read protocol on Illumina HiSeq 4000 platform (1×50 bp), which obtained ˜100 million to 200 million reads per lane (around 1,000,000 reads per sample in current setting).
Raw data from Illumina HiSeq 4000 platform was processed by BCL2FASTQ2 for demultiplexing and converting binary base calls and qualities to fastq format. The fastq files were mapped to original virome peptide reference sequences using the Bowtie program. Two sequencing samples were cut off from next-step analysis as their reads were less than 30,000. The initial informatics and statistical analysis were performed using a slightly modified version of the previously published technique and in-house scripts. Briefly, the scatter plots of the log 10 of the −log 10 (P values) and a sliding window of width 0.005 from 0 to 2 across the axis of one replicate were used. It was determined that the distribution of the threshold −log 10 (P value) was centered around a mode of ˜2.358 (
DNA extraction from buffy coat or lymphocyte samples was performed following the manufacturer's instruction (DNeasy Blood & Tissue Kit from Qiagen). The eluted DNA was stored at −20° C. for further analysis.
Illumina OmniExpress was applied for the SNP array. Genotyping was performed on 200 ng of genomic DNA using Illumina Infinium HTS Global Screening Arrays on an Illumina iScan system. The raw genotyping data were processed by Illumina GenomeStudio software 2.0. Quality control was performed using PLINK version 2.0 (available online). Samples with a genotyping call rate<95% were removed. SNPs with MAF (Minor Allele Frequency)<0.05, HWE (Hardy-Weinberg equilibrium)<10-4, and call rate<95%, were excluded.
Variant quality control was performed. After filtering, 849 individuals and 713,111 SNPs remained for further analysis, with the total genotyping rate 99.79%. Hardy-Weinberg equilibrium deviation was flagged at p value <0.0001. Independent loci in regions were identified for SNPs associated with virus feature phenotype at P<5×10-7 using PLINK. LocusZoom was used to plot regional signals associated with phenotype with LD and recombination rate calculated from 1000 Genome. LD structure of signals were further investigated with Haploview. A linear regression with additive model was applied to estimate the genotypic effect the SNP contributed to the disease or phenotype.
IgG, IgA and IgG4 levels in serum were measured using human ELISA kits (Bethyl and Thermo Fisher) according to the manufacturers' instructions. ELISA result reading was performed using a machine (Biorad).
To identify differences between populations, Xgboost and LEfSe were used to calculate the significance of association of virus exposure traits with HCC versus PC.
XGBoost (available online) is software for a machine learning method of regression and classification using ensemble learning with gradient tree boosting. It is designed to increase the scalability and acceleration of optimized computation for practical use. XGBoost includes three types of parameters—general, booster and task. Each of the types has several hyperparmeters, such as maximum depth of the regression trees, number of weak learners, learning rate, and regularization, that need to be tuned. These parameters were tuned using a grid search to maximize the mean AUC value computed from 5-fold cross validation on the training data. After finding the optimal values of the hyperparameters, the model was constructed using the following main parameter setting: max_depth=3, eta=0.1, subsample=1, colsample_bytree=0.5, and min_child_weight=1. Then XGBoost was applied to the entire data set with 200 boosting iterations. To avoid over-fitting, stop model training at least 20 rounds when no improvement was observed in AUC value was set (early_stopping_rounds=20). The best iteration model was used as the final model. XGBoost automatically conducts feature selection and calculates importance for each feature. Multiple subsets of the features were tested to achieve the highest AUC and a decision was made to take all of the output features for further analysis. For each training and testing sample, a virus feature score was also generated based on the features selected and implemented in the XGBoost classification prediction.
The LEfSe method of analysis first compares abundance of all viral clades (in this case between PC and HCC) by Kruskal-Wallis test at a pre-defined a of 0.05. Significantly different vectors resulting from the comparison of relative abundances between PC and HCC are used as input for linear discriminant analysis (LDA), which produces an effect size and a p-value. The LDA threshold on the logarithmic LDA score for discriminative features is set up at 2.0. LEfSe also calculated the hierarchically organized viral taxa. The relative abundance data for Lefse test was prepared based on strain and species score data.
All analyses were conducted in R and GraphPad Prism 7 (La Jolla, Calif.) and used for statistical analyses. Data are presented either as means+/−s.e.m. or medians of continuous values and were analyzed by a two-sided Student's t-test or Mann-Whitney test used for comparison of two groups, respectively. Fisher's exact X2 t-test was used to calculate statistical significance of categorical values between groups. Two-tail P values with no more than 0.05 were considered significant. Linear regression was used to determine the correlation between two different variables.
All HCC patients were classified into high, low or below viral feature score groups based on viral feature levels (
This example describes the development of two virus exposure signatures—a first VES based on detection of 61 viral strains and a second VES based on detection of 31 viral strains—to identify subject's at risk for developing HCC.
VirScan applies a phage display library that covers 93,904 viral epitopes, representing 206 human viral species and over 1000 viral strains, to screen for previous exposure history (Xu et al., Science 2015; 348:aaa0698). A phage particle with an epitope that was recognized by a participant's antibody was immunoprecipitated (Phage-IP), and the encoding DNA barcode was then sequenced (
To further assess the quality of VirScan, the results of VirScan were compared to available medical chart entries for HCV, HBV and HIV testing results and found that VirScan had 45%, 47% and 70% specificity in detecting HCV, HBV and HIV, respectively, when compared to these medical record data (
A gradient boosting approach was applied to search for the best-fit virus composition that can discriminate HCC from PC (
A phylogenetic analysis of the reactive epitopes of the 61 viral strains was performed to determine similarity among these HCC-related viruses (
Another statistically conserved method, the linear discriminant analysis of effect size (LEfSe, or LDA) (Segata et al., Genome Biol 2011; 12:R60), was used to search for HCC associated viruses. Furthermore, pairwise comparisons were performed for viral taxa at all levels including DNA/RNA viruses, viral families, viral species and viral strains between HCC and PC. In addition to VES at the strain level, this analysis also identified the viral taxonomic differences by viral families, such as Flaviviridae of positive single-strand RNA viruses, Pneumoviridae of negative single-strand RNA viruses and Circoviridae of single-strand DNA viruses. These analyses resulted in 341 viruses that can significantly distinguish HCC from PC. Among them, several HCV variants, herpesvirus 5 variants, Norwalk virus variants, cytomegalovirus, adenovirus variant and astrovirus-1 were uniquely different between PC and HCC (
To further validate the two VES identified above for their clinical utility, VirScan profiles in the at-risk NIDDK cohort for HCC was analyzed. This cohort consisted of 173 CLD patients (NIDDK-HR) who were enrolled for a natural history study for liver disease with a follow-up of up to 20 years (Table 1;
Table 9A shows the results from univariable and multivariable Cox model survival analysis on several clinicopathologic variables to clarify the independent and additional prognostic value of VES. Among patients from the NIDDK cohort, VirScan data were available for 40 HCC cases at baseline, 129 controls at baseline, 44 HCC cases at diagnosis and 106 controls at diagnosis. It was found that the AUC values were 0.98, 95% CI (0.97-1.00) at diagnosis (
Phenotype-Genotype Association with VES
To determine if host genetic background may be linked to VES, a genome-wide association study (GWAS) in the Maryland cohort was performed, as this approach may help identifying susceptibility variants related to viral infection and cancer (McKay J et al., Nat Genet 2017; 49:1126-1132; Pharoah et al., Nat Genet 2013; 45:362-370; Fumagalli et al., PLoS Genet 2010; 6:e1000849). After assessment using the genetic quality control measures, 849 participants (PC, n=402; HR, n=323; HCC, n=124) were included in the analysis. Following the removal of monoallelic SNPs and the ones that deviate away from Hardy-Weinberg equilibrium, an association test was performed for all the remaining SNPs. To further assess the quality of the GWAS data, it was determined whether there was an association between an SNP, rs12979860 in IL28B, and HCV infection. As its favorable genotype, CC has been shown to be associated with better HCV treatment response or natural clearance. It was found that rs12979860-CC was significantly associated with HCV genotype 3 with odds ratio (OR) 2.74 (95% CI 1.14-7.97) in a dominant model manner (Table 3A). Furthermore, the SNP associated with 375 epitopes abundances of HCV genotype 2 and 3 was evaluated. The CC allele was found to be associated with a decreased abundance of core epitopes but an increased abundance of NS5B epitopes in the HCV genome (
Manhattan plot analysis revealed several SNPs with much larger differences between high and low VES scores having the p-values <10−5 (
Detecting cancer at an early stage preferably before it is symptomatic may provide an opportunity in achieving a cure and improving outcomes on cancer-related mortality. Evidence suggests that earlier detection of cancer improves survival for some cancer types, such as cervical and colon cancers. A conventional approach is to develop biomarkers specific for cancer cells to aid in early cancer diagnosis. CancerSEEK is an emerging platform successful in achieving a good sensitivity and specificity to clinically-detected multiple cancer types by profiling circulating cell-free DNA (ctDNA) presumably shed from tumor cells (Cohen et al., Science 2018; 359:926-930). A recent study offers a cautionary note for measuring cancer gene panels using ctDNA because of its high false positivity among healthy individuals (Liu et al., Ann Oncol 2019; 30:464-470). Molecular and biological heterogeneity of cancer cells contributed by complex etiological landscape creates a dilemma as how best to design cancer-specific diagnostic panels effective for early cancer detection. As such, a continuous debate has been carried out in recent decades for many malignant diseases including HCC as whether available methods are adequate in achieving this goal (Sherman et al., Hepatology 2012; 56:793-796; Shieh et al., Nat Rev Clin Oncol 2016; 13:550-56).
HCC is a unique malignancy for which most major causative etiologies are known (Wang and Thorrgeirsson, Oncology 2014; 1:5). However, defining biomarkers specific for HCC cells has been challenging because of its complex genomic landscape with extensive intratumor and intertumor heterogeneities. Are there common features shared among HCC patients to be used as a surrogate for early detection? An emerging concept is that an interplay between viral infection and host genetic background is crucial for maintaining virome homeostasis or causing human disease (Virgin, Cell 2014; 157:142-150). The study disclosed herein assessed how a history of viral exposures by an individual is associated with their risk of developing HCC. Using a synthetic viral scan technology (VirScan) with a simple blood test (Xu et al., Science 2015; 348:aaa0698), a VES was identified that could discriminate HCC with a high confidence from individuals with chronic liver diseases or from healthy volunteers. Remarkably, this signature was able to identify individuals at a medium follow-up year of 8.8 prior to a clinical diagnosis of HCC. Thus, these results offer a sensitive tool applicable to the HCC surveillance program to improve early diagnosis.
The current study took the advantage of a simple tool to profile serological samples to link an individual's history of viral infection and corresponding response to early onset HCC. The strategy was first to search VES using a case control design that include HCC cases as well as at-risk individuals with chronic liver diseases and healthy volunteers matched by age and sex. A VES that can discriminate HCC from at-risk and healthy individuals was then validated using a prospective cohort of sequentially enrolled at-risk patients who were followed up for the development of HCC. The VES consists of known HCC etiologies such as HCV, HBV and HDV, but also includes other viruses such as herpesviruses 4 and 5, Crimean-Congo hemorrhagic fever virus, cytomegalovirus, and influenza A virus, among others. A few features are noted. First, HCV appears to be a major etiology driving VES but an extended heterogeneity in various HCV subtypes are noted in both Maryland and NIDDK cohorts. Second, a set of viruses are enriched while many others including HBV are depleted in HCC patients.
The current method of VirScan is based on the phage immunoprecipitation sequencing (PhIP-Seq) technology that provides a powerful approach for analyzing antibody-repertoire binding specificities with high throughput and at low cost to all known human viruses (Mohan et al., Nat Protoc 2018; 13:1958-1978). Comparing VirScan results with HCV and HBV status from medical chart of the UMD cohort, it was found that VirScan shows great specificity for both HCV and HBV, and good sensitivity for HCV but to a lesser extent for HBV. HCV encodes a large polyprotein consisting of ˜3,000 amino acids, which is cleaved co- and post-translationally into ten different proteins associated with intracellular membranes (Bartenschlager et al., Nat Rev Microbiol 2013; 11:482-496). Consistently, HCV antigen reactivity largely overlapped with the predicted antigenicity score by the B-cell epitope prediction method coinciding with peptides to be presented at the surface of the cellular membrane. Consistent with early reports for the likelihood of coinfection of HIV and other viruses associated with AIDS and non-AIDS diseases (Xu et al., Science 2015; 348:aaa0698; Slyker et al., J Infect Dis 2013; 207:1798-1806; Lichtner et al., J Infect Dis 2015; 211:178-186), evidence of coinfection between HIV and viruses such as HBV, herpesvirus 8 and adenovirus D, influenza B virus, adenovirus C, and herpesvirus 5 was found in patients enrolled in the Maryland cohort. History of HCV infection is prevalent among at-risk (48%), HCC patients (39%) and healthy volunteers (4%) who reside in Maryland. This is in contrast to an estimated prevalence of about 4.6 million persons (˜1.5%) infected with HCV in the U.S. (Edlin et al., Hepatology 2015; 62:1353-1363). It should be noted that 7.5%-44% of incarcerated individuals and 4%-38% of hospitalized patients tested positive for HCV (Edlin et al., Hepatology 2015; 62:1353-1363), suggesting that the current surveys underestimate the prevalence of HCV infection. In contrast, while 2.6% of the Maryland healthy individuals showed evidence of HBV infection, more than 800,000 chronic HBV carriers were detected during 2011-2012 in the noninstitutionalized U.S. population (Roberts et al., Hepatology 2016; 63:388-397). The current survey methods may underestimate the prevalence of HBV and HCV. This is important as both HBV and HCV are major causative factors for HCC. Collectively, VirScan is a reliable method for profiling viral exposure and is scalable regarding to sample throughput and relatively low cost per analysis amenable for surveillance and early detection of HCC.
1PC: population control
2HR: high risk group
3HCC: hepatocellular carcinoma
aOR: Odds Ratio
1Allels: Minor/Major allele
2OR: Odd Ratio
1PC: population control;
2HR: high risk group;
3HCC: hepatocellular carcinoma;
4OR: Odd Ratio
5Ptrend: Calculated by wald test from logistic regression
2Importance score: the improvement in accuracy brought by a feature to the decision tree branches it is on. The higher the score is, the more important the feature is to the module prediction
1PC: population control, HCC: hepatocellular carcinoma
2LDA score: Linear discriminant analysis (LDA) effect size, the degree of consistent difference in relative abundance between features in the two groups
1EUR is European and AFR is African from 1000G Phase 1 population
2chr is chromatin
3pos(hg38) is the position on human reference genome version 38
4Ref stands for reference sequence
5Alt stands for alternative sequence
6eQTL is Expression quantitative trait loci; eQTL information is from gtexportal.org/home/
1PC: population control;
2HR: high risk group;
3HCC: hepatocellular carcinoma;
4P-value: p-value was calculated by t-test or Chi-seq test, with 2 tailed
aUnivariable Cox regression.
bMultivariable Cox regression.
In view of the many possible embodiments to which the principles of the disclosed subject matter may be applied, it should be recognized that the illustrated embodiments are only examples of the disclosure and should not be taken as limiting the scope of the disclosure. Rather, the scope of the disclosure is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.
This application claims the benefit of U.S. Provisional Application No. 62/914,138, filed Oct. 11, 2019, which is herein incorporated by reference in its entirety.
This invention was made with government support under project number Z01-BC010313 awarded by the National Institutes of Health. The government has certain rights in the invention.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/055077 | 10/9/2020 | WO |
Number | Date | Country | |
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62914138 | Oct 2019 | US |