Effects of the streptococcal preparation OK-432 on in vitro cytokine production of peripheral blood mononuclear cells in patients with chronic viral hepatitis.

We obtained peripheral blood mononuclear cells from 12 chronic hepatitis Type B patients, 12 Type C patients, and 15 healthy volunteers, and investigated the effects of OK-432, a streptococcal preparation, on in vitro production of 3 types of cytokines. Mononuclear cells in a concentration of 1 x 10(6) cell/ml were prepared in the culture medium. OK-432 (Chugai Pharmaceutical Co., Ltd., Tokyo) was added to this preparation and incubated for one to 4 days. Thereafter interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and interferon-gamma (IFN-gamma) levels in the culture supernatant were measured using enzyme-linked immunoassay kits. Cytokine production levels in cultures with OK-432 were significantly increased in the mononuclear cells of both patients and healthy volunteers. The largest increase was observed with IFN-gamma (p < 0.01), and then with IL-1 beta (p < 0.05). Responses of the cells from chronic hepatitis Type C patients to OK-432 were relatively good. When interferon (alpha and beta) treatment was first introduced, there were high hopes for a high efficacy. However, we now know 50-70% of patients with chronic hepatitis Type C do not respond satisfactorily to interferon. Some physicians suggest the necessity of using biological response modifier (BRM) as an adjuvant treatment for these patients. From our findings, OK-432 could be a useful BRM in patients with chronic hepatitis Type C.