Changes in the Th1/Th2 ratio during a 24-week course of an interferon alpha-2b plus ribavirin combination therapy for...

It has been reported that immunological factors, such as the T-helper cell (Th)1/Th2 ratio, play a part in the mechanisms for the antihepatitis C virus (HCV) effect of the interferon (IFN) alpha-2b plus ribavirin combination therapy. By using flow cytometry, we examined this ratio during a 24-week course of combination therapy for patients with chronic hepatitis C.

We recruited 21 patients with chronic hepatitis C (16 males, five females, genotype 1b, 17 patients; genotype 2a or 2b, four patients) who had been treated by combination therapy. Flow cytometry was used to examine the Th1/Th2 ratio before and at the 4th and 24th week of therapy. Patients who were HCV-RNA negative 24 weeks after the treatment was completed were defined to show sustained virological response (SVR).

Among the 21 patients, 10 showed SVR, the overall SVR rate being 47.6%. Patients were classified into an 'increase group' (Th1/Th2 ratio at 4 or 24 weeks of therapy being higher than those before therapy) and a 'decrease group' (the ratio being lower than before therapy). After 24 weeks of therapy, the SVR rate was 66.7% for the Th2 'increase group' and 14.3% for the Th2 'decrease group'. The former showed a significantly higher SVR rate (P = 0.0361).

The significant changes in the Th2 level correlated with the therapeutic effect during the IFN alpha-2b plus ribavirin combination therapy. The increase of the Th2 level during therapy could be a predictor for achieving SVR.