Objectives: To analyze the T1/T2 cytokine profile in CD8 T cells from peripheral blood mononuclear cells from patients with genotype-1 CHC during treatment with pegylated interferon (Peg-IFN) alpha2a plus ribavirin (RBV). To correlate Th1/Th2 balance with virological response.
Patients and methods: In this prospective longitudinal study, a total of 28 naïve genotype-1 CHC patients received Peg-IFNalpha2a (180 microg/week) plus RBV (1-1.2 g/day) for 48 weeks. All patients (mean age 45 +/- 8 years) completed treatment and follow-up: 12 (43%) achieved a sustained virological response (SVR), 13 relapsed after end of treatment (47%), and only 3 (10%) were non-responders. Sixteen healthy controls were also analyzed (mean age 39 +/- 17 years). The production of IL-4, IFNgamma, and TNFalpha by CD8 T cells was measured by intracytoplasmic detection using flow cytometry in both resting and stimulated cells with a phorbol ester.
Statistics: Student's t test for independent values, chi2 test, and ANOVA test were used; relapsers and non-responders were joined to achieve a higher statistical power.
Results: At third month during treatment, phorbol ester-stimulated-IL-4 levels tend to be lower in patients who presented with SVR versus those who did not (0.97 vs 2.58; p = 0.1). No statistically significant differences were found in IFNgamma and TNFalpha levels at month 3. At EOT, the stimulated-IFNgamma production was significantly higher in patients with SVR (20 vs. 8; p < 0.05). Conversely, IL-4 production was higher in NR patients although these data did not reach statistical significance (p < 0.1). No significant differences were found in TNFalpha (14 vs. 7; p < 0.2).
Conclusions: Cytokine T1 induced-response maintenance during combination treatment, measured as IFNgamma production by CD8+ T lymphocytes, is associated with SVR and suggests the replication control and later clearance of patients infected by genotype-1 HCV.