Prevalence of non-organ-specific autoantibodies and chronic liver disease in the general population: a nested case-control study of the Dionysos cohort

Background-Several retrospective and prospective studies report an increase d prevalence of non-organ-specific autoantibodies (NOSAs) in patients with hepatitis C virus (HCV) related chronic liver disease (CLD). Some of the da ta so far available are controversial and the true prevalence of NOSAs in t he general population is still not known. Aim-To explore the prevalence of NOSAs, their relation to different HCV gen otypes, and the presence and severity of CLD in the general population of N orthern Italy. Patients-All 226 anti-HCV positive and 87 hepatitis B surface antigen (HBsA g) positive patients of the Dionysos cohort study were analysed and compare d with sex and age matched cases (226) negative for both anti-HCV antibody and HBsAg selected from the same cohort. Methods-Sera tested for the presence of NOSAs (anti-nuclear antibody (ANA), anti-smooth muscle antibody (SIMA), and anti-liver/kidney microsomes type 1 antibody (LKM1)) were screened by indirect immunofluorescence at a 1:40 s erum dilution. HCV RNA and HCV genotypes were also determined by nested pol ymerase chain reaction (PCR) of the 5' non-coding region and by PCR amplifi cation of the core region with type specific primers. Results-The overall prevalence of NOSA reactivity was significantly higher in anti-HCV positive subjects than in both normal and pathological controls (25% upsilon 6% and 7% respectively, p<0.05). ANA, SMA, and LKM1 occurred in 16, 10, and 1.3% of cases respectively. No specific association between NOSAs and a specific HCV genotype was found. NOSAs were found more often as sociated with more than one genotype (35.7%) and with untypable genotypes ( 34.6%), although the association was not statistically significant. NOSAs w ere associated with HCV RNA and CLD but not with the presence of cirrhosis and/or hepatocellular carcinoma. On univariate analysis, NOSA reactivity wa s independently associated with abnormal alanine aminotransferase (p<0.01) and gamma-glutamyltranspeptidase levels (p<0.05). The risk for the presence of NOSAs was 5.1 times higher in anti-HCV subjects than in controls. Conclusions-In the general population the prevalence of NOSAs is higher in anti-HCV positive subjects than in normal or disease controls. Moreover NOS As are associated with CLD and with a more active disease in terms of alani ne aminotransferase activity.