Lack of effect of chronic hepatitis C virus infection on T-cell cytokine production in chronic hemodialysis patients

It has been shown that chronic hemodialysis modifies, to some extent, the n ormal immune response by both T and B lymphocytes elicited by antigenic sti mulation, e.g. by impairing the T-cell-dependent response after vaccination . A new technique, i.e. flow cytometry, enables to assess intracytoplasmica lly, at the single cell level, the production of a given cytokine. By using it, we studied in healthy volunteers (HV) and in chronic hemodialysis (CHD ) patients, with respect to their hepatitis C virus (HCV) status, the produ ction by the T lymphocytes of type 1, and type 2 cytokines. We studied the following cytokines (CK): IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma and TNF- alpha in the T-cell lymphocytes (whole, CD4+ and CD8+). There were 13 HV an d 59 CHD patients (36 HCV(-) and 23 HCV(+)). Amongst the latter, there were 32 men and 27 women, aged 59.5 +/- 2 years, undergoing CHD since 70 +/- 9. 4 months. We found that: (1) the total number of lymphocytes as well as tho se expressing CD3, CD4, or CD19 were significantly decreased in CHD patient s as compared to those from HV; (2) the total number of lymphocytes as well as their different subsets were similar in HCV(+) and in HCV(-) CHD patien ts; (3) the frequency of T-cell-expressing IL-5 or IL-10 was always low (<1 %) in both HV and CHD groups; (4) overall in CHD patients, the mean percent ages of T lymphocytes expressing IL-2, IL-4, IFN-<gamma> or TNF-alpha were respectively 31 +/- 13, 2.5 +/- 1.3, 28 +/- 12 and 34 +/- 11% and were not statistically different between HCV(+) and HCV(-) patients; (5) IL-2 was ma inly produced by CD4+ T cells, whereas IFN-gamma was produced by CD8+ T cel ls, in both HV and CHD groups, and (6) the lymphocytes of CHD patients prod uced significantly more IL-2 and IL-4 than those from HV, suggesting an act ivation of their T lymphocytes. We conclude that using the cytokine flow cy tometry assay, our study demonstrated that in HCV(+) CHD patients, as oppos ed to what has been described for HCV(+) patients with normal renal functio n, there was no impairment in the production of type 1 cytokines by periphe ral blood mononuclear cells when compared to HCV(-) CHD patients. Conversel y to HV, T lymphocytes from CHD patients are activated. Copyright (C) 2001 S. Karger AG, Basel.