[Clinical significance of IgM anti-HCV determination in chronic hepatitis C]

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.

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.

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.