Autoantibodies and hepatitis C virus genotypes in chronic hepatitis C patients in Estonia

To determine the prevalence of several autoantibodies in chronic hepatitis C patients, and to find out whether the pattern of autoantibodies was associated with hepatitis C virus (HCV) genotypes.

Sera from 90 consecutive patients with chronic hepatitis C were investigated on the presence of anti-nuclear (ANA), anti-mitochondrial (AMA), anti-smooth muscle (SMA), anti-liver-kidney microsomal type 1 (LKMA1), anti-parietal cell (PCA), anti-thyroid microsomal (TMA), and anti-reticulin (ARA) autoantibodies. The autoantibodies were identified by indirect immunofluorescence. HCV genotypes were determined by a restriction fragment length polymorphism analysis of the amplified 5' noncoding genome region.

Forty-six (51.1%) patients were positive for at least one autoantibody. Various antibodies were presented as follows: ANA in 13 (14.4%) patients, SMA in 39 (43.3%), TMA in 2 (2.2%), and ARA in 1 (1.1%) patients. In 9 cases, sera were positive for two autoantibodies (ANA and SMA). AMA, PCA and LKMA1 were not detected in the observed sera. HCV genotypes were distributed as follows: 1b in 66 (73.3%) patients, 3a in 18 (20.0%), and 2a in 6 (6.7%) patients.

A high prevalence of ANA and SMA can be found in chronic hepatitis C patients. Autoantibodies are present at low titre (1:10) in most of the cases. Distribution of the autoantibodies show no differences in the sex groups and between patients infected with different HCV genotypes.