BACKGROUND: In the majority of patients with acute viral hepatitis C the early antibody IgM anti-HCV in serum is positive. However, a substantial portion of the patients with chronic hepatitis C has also positive IgM anti-HCV as a sign of the continuing replication of the virus. The objective of the work was to assess the presence of IgM anti-HCV in patients with confirmed chronic hepatitis C, in subjects with HBsAg negative chronic hepatitis and in excluded blood donors. Moreover, the authors assessed the relationship between IgM anti-HCV positivity and the activity of serum transaminases and whether the presence of IgM anti-HCV has an impact on the histological finding in the liver. METHODS AND RESULTS: 88 patients were examined (44 women and 44 men), average age 48 years. In 47 subjects histological examinations of the liver were made. IgG anti-HCV were assessed by the Monolisa anti-HCV Sanofi Pasteur test and IgM anti-c22 by an Abbott kit IgM HCV EIA: With regard to the results of the serological examination the patients were divided into three groups which were mutually compared. Group 1 comprised 24 patients with a positive IgG and IgM anti-HCV, group 2 38 patients with a positive IgG anti-HCV only and group 3 26 patients with a negative IgG and IgM anti-HCV. Of 88 examined patients 62 had positive IgG anti-HCV (70%). Of 62 IgG anti-HCV positive subjects 24 (39%) had positive IgM anti-c22. A total of 24 patients had blood transfusions (39%) but only 9 of them had positive IgM anti-c22 (37.5%). The mean ALT serum activity was significantly higher in subjects with positive IgM than in those without IgM (p = 0.006), however, for AST the difference was not significant (p = 0.09). Comparison of patients with a confirmed histological finding in the liver revealed that two-thirds of patients with a positive IgM anti-c22 either suffered from cirrhosis or chronic active hepatitis, while anti-HCV positive patients without IgM anti-c22 had cirrhosis or chronic active hepatitis only in one third of the cases. CONCLUSIONS: The results suggest that in chronic hepatitis C some 40% of the patients have positive IgM anti-c22; these subjects have a significantly higher serum ALT activity and a more advanced histological finding in the liver than subjects without IgM anti-c22. Assessment of IgM anti-c22 is important not only for diagnosis but also for treatment of chronic HCV infection with antiviral drugs.

1 interní klinika 3 LF UK Praha