title: Virus-specific effector CD4+ T-cell responses in hemodialysis patients with hepatitis C virus infection.
abstract: Patients with chronic renal failure undergoing hemodialysis who are infected with hepatitis C virus (HCV) may test consistently anti-HCV negative. Because CD4(+) T-cells provide help for antibody production virus-specific effector CD4(+) T-cell responses were investigated in relation to anti-HCV positivity in 15 hemodialysis patients grouped according to HCV antibody and viremia. CD4(+) T-cell reactivity was studied in peripheral blood mononuclear cells by standard lymphocyte proliferation assay and phenotypic/functional characterization (cell-surface staining/cytokine secretion) by flow cytometry. HCV-specific CD4(+) T-cell proliferation in viremic hemodialysis patients was weak or absent independently of their anti-HCV status. Virus-specific CD4(+) T-cells displayed a memory phenotype and showed low to undetectable capacity to secrete effector interferon (IFN)-gamma. Impaired activation-induced cytokine secretion appeared to be Th1 (IFN-gamma) but not Th2 (interleukin-4)-directed and was virus-specific as cytomegalovirus responses were preserved. The frequency ex vivo of CD3(+)CD4(+)IFN-gamma(+) T-cells was independent of the HCV antibody status and comparable between viremic (range: 0.08-1.54%) or non-viremic (0.11-3.2%) hemodialysis patients and healthy donors (0.13-1.10%; P = 0.58). The numbers of CD3(+)CD4(+)IFN-gamma(+) T-cells augmented slightly (P = 0.047) in HCV-infected hemodialysis patients but markedly in only one (greater than ninefold) after HCV stimulation. In conclusion, hemodialysis patients show limited HCV-specific effector CD4(+) Th1-cell responses which nonetheless seem unrelated to the anti-HCV status and are not more impaired due to the ongoing hemodialysis.
authors.affiliation: Fundación para el Estudio de las Hepatitis Virales, Madrid, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Rico
authors.forename: Sara
authors.initials: S
authors.lastname: Ruiz
authors.forename: Dolores
authors.initials: D
authors.lastname: Subirá
authors.forename: Guillermina
authors.initials: G
authors.lastname: Barril
authors.forename: Secundino
authors.initials: S
authors.lastname: Cigarrán
authors.forename: Susana
authors.initials: S
authors.lastname: Castañón
authors.forename: Juan A
authors.initials: JA
authors.lastname: Quiroga
authors.forename: Rafael
authors.initials: R
authors.lastname: Selgas
authors.forename: Vicente
authors.initials: V
authors.lastname: Carreño
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017252:CD3 Complex / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D006526:Hepatitis C / Q000150:complications* / Q000276:immunology; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D018937:Hepatitis C Antibodies