[IgM- and IgG-class antibodies to the hepatitis C virus]

The test system widely used currently for the determination of anti-HCV permits the detection of anti-HCV IgG alone. The data recently published by T. G. Wreghitt et al. confirm the probability of the presence of anti-HCV of both IgG and IgM classes in sera from hepatitis C patients. Anti-HCV IgM was detected by Ortho test with some modifications using an anti-M conjugate in the last stage of the experiment. Anti-HCV IgG were detected by regular Ortho test. A total of 46 patients with different forms of HCV infection and a control group were examined. According to the preliminary data, 18 patients were positive in the routine anti-HCV Ortho test. Among 18 anti-HCV-positive patients, nine had chronic HCV infection and the other 9 acute HCV infection. The distribution of IgM and IgG anti-HCV in the acute patients was as follows: 4 patients (44.5%) had approximately equal titres of IgG and IgM, 3 (33.5%) had predominantly IgG, 2 (22.2%) mainly IgM. A similar pattern was observed in the group with chronic HCV infection. Thus, 5 subjects (55.6%) showed approximately equal ratio of IgM and IgG anti-HCV, 2 (22.2%) had mostly IgM and the rest 2 mainly IgG. No anti-HCV in the control group was found. The control group consisted of 18 patients with chronic liver diseases without markers of HBV or HDV infection, 3 with HAV infection, 2 with HBV infection and 5 healthy subjects. The specificity of anti-HCV IgM test was confirmed by Chiron Western blot analysis using the same modification.(ABSTRACT TRUNCATED AT 250 WORDS)