Detection of Antibody to Calmodulin in Chronic Viral Hepatitis: Lack of Correlation with Virus Replication and Hepatocellular Damage

We have analyzed the presence of IgG and IgM anti-calmodulin antibodies (anti-CaM) by ELISA in patients with chronic hepatitis due to B, delta and C viruses as well as in patients with other liver diseases. The specificity of the assay was demonstrated by preadsorption of positive serum with calmodulin (CaM) but not with myosin light chain. Among 164 patients with chronic viral hepatitis (B, delta and C) and 50 with non-viral hepatitis, 27 and 26%, respectively, had auto antibodies against CaM. There was a significantly increased frequency (37%) of these auto-antibodies in chronic delta infection as compared to that (21%) of patients with chronic B hepatitis (p less than 0.05). An intermediate incidence of anti-CaM, (24%) was found in chronic C infection. The frequency of anti-CaM was not related to the level of hepatitis B virus (HBV) or hepatitis delta virus (HDV) replication. A high occurrence of anti-CaM in the presence of liver membrane antibody (p less than 0.03) was observed. During follow-up of patients with chronic delta-hepatitis, the presence of anti-CaM was consistently observed, when the isotype was IgM, but transiently when it was IgG. The occurrence of anti-CaM correlated neither with ALT levels nor with histological diagnosis. Antibodies to CaM, are present in liver diseases especially in chronic delta-hepatitis, and do not play a pathogenic role on hepatocellular damage.