Background: Clearance of hepatitis C virus (HCV) is attributed to host cellular immune responses, in which T helper cells play a critical role. The purpose of the present paper was therefore to study the serial changes of serum soluble markers released from T helper 1 (Th1) and 2 (Th2) and their correlations with treatment responses in chronic hepatitis C patients receiving interferon-alpha plus ribavirin for 24 weeks.
Methods: Serum markers (soluble CD26 and CD30 levels) of T helper cells were quantified before and 6 months after combination therapy in 33 chronic hepatitis C patients and in 20 healthy controls.
Results: Compared to healthy controls, chronic hepatitis C patients had significantly lower serum soluble CD26 levels before (140.4 +/- 63.9 ng/mL vs 200.6 +/- 60.3 ng/mL, P < 0.0001) and after (115.9 +/- 32.9 ng/mL vs 200.6 +/- 60.3 ng/mL, P < 0.0001) combination therapy. The level was even lower in those with non-sustained virologic response (non-SVR; 139.0 +/- 50.9 ng/mL vs 117.7 +/- 40.3 ng/mL, P = 0.039). In contrast, soluble CD30 levels at 6 months after combination therapy were significantly lower in patients with SVR than those with non-SVR (6.4 +/- 3.5 U/mL vs 10.4 +/- 5.4 U/mL, P = 0.021).
Conclusion: Chronic hepatitis C patients have a weak Th1 response as reflected by lower soluble CD26 levels and the levels are even lower in non-sustained responders. In sharp contrast, downregulation of Th2 response with serial changes of soluble CD30 level is associated with successful treatment of HCV infection.