title: Quantitative analysis of anti-hepatitis C virus antibody-secreting B cells in patients with chronic hepatitis C.
abstract: To investigate the quantitative characteristics of humoral immunity in patients with hepatitis C, we established an enzyme-linked immunosorbent spot (ELISpot) assay for detection of anti-hepatitis C virus (HCV)-secreting B cells. Receiver operating characteristic curve analysis demonstrated 100% specificity and 58% to 92% sensitivity for detecting B-cell responses to NS5b, NS3, E2, and core antigens. The median sum of anti-HCV-secreting B cells to all HCV antigens tested was significantly higher in 39 patients with chronic hepatitis C (47.3 spot forming cells [SFCs]/10(6) peripheral blood mononuclear cells [PBMCs]) than in 9 recovered subjects (15.3 SFCs/10(6) PBMCs; P = .05) or 11 uninfected controls (5.3 SFCs/10(6) PBMCs; P < .001); the significant difference (P = .018) in chronic versus recovered patients was in reactivity to nonstructural antigens NS3 and NS5b. Anti-HCV immunoglubulin M (IgM)-secreting B cells were also readily detected and persisted decades into HCV infection; there was no difference in IgM-positive cells between chronic and recovered patients. ELISpot reactivity to genotype 1-derived antigens was equivalent in patients of genotypes 1, 2, and 3. There was significant correlation between the numbers of anti-HCV IgG-secreting B cells and serum aminotransferase and to the level of circulating antibody. In conclusion, ELISpot assays can be adapted to study B-cell as well as T-cell responses to HCV. Measurement at the single-cell level suggests that humoral immunity plays a minor role in recovery from HCV infection and that B-cell immunity is strongest in those with persistent infection.
authors.affiliation: Department of Transfusion Medicine, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892-1184, USA.
authors.forename: Takeji
authors.initials: T
authors.lastname: Umemura
authors.forename: Richard Y-H
authors.initials: RY
authors.lastname: Wang
authors.forename: Cathy
authors.initials: C
authors.lastname: Schechterly
authors.forename: J Wai-Kuo
authors.initials: JW
authors.lastname: Shih
authors.forename: Kendo
authors.initials: K
authors.lastname: Kiyosawa
authors.forename: Harvey J
authors.initials: HJ
authors.lastname: Alter
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000145:classification / Q000235:genetics; D018937:Hepatitis C Antibodies / Q000096:biosynthesis*; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D012372:ROC Curve
chemical_list: D018937:Hepatitis C Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M