NON-ORGAN SPECIFIC AUTOANTIBODIES IN CHILDREN WITH CHRONIC HEPATITIS-C

Background/Aims: Recent studies in adult patients have established a r elationship between hepatitis C virus infection and the presence of li ver-kidney microsomal autoantibody type 1 (LKM1). Conversely, little i s known regarding the relationship between hepatitis C and autoimmunit y in children, In this study, me investigated non-organ specific autoa ntibodies in 40 otherwise healthy Italian children with chronic hepati tis C. Methods: All but four patients included in the study were asymp tomatic, Liver histology, obtained in 35, showed features ranging from minimal to mild chronic hepatitis. Autoantibodies were investigated b y indirect immunofluorescence. HCV RNA was assayed by the polymerase c hain reaction in 34 cases and viral genotypes were determined. Results : Antinuclear antibodies were detected in three (7.5%) cases, one with a homogeneous pattern; smooth muscle autoantibodies in seven (17.5%) cases, always with V (vessels only) specificity and LKM1 in four (10%) , at titers ranging from 1:20 and 1:2560, Clinical and virologic featu res did not significantly differ between autoantibody positive and neg ative cases, although infections with I-ICV genotypes la and 2 were mo re frequent in LKM1-positive patients, During observation, the child w ith the highest LKM1 titre was unsuccessfully treated with alpha inter feron but responded to steroids, Twelve LKM1 negative children were al so treated with interferon and one developed low LKM1 titers concomita nt with an alanine aminotransferase flare, The sera of the five LKM1-p ositive children were investigated by immunoblotting with a human micr osomal fraction and peptide 257-269 of cytochrome P450IIPD6. Only the serum of the child with the highest LKM1 titers was reactive. Conclusi ons: These results show that a consistent proportion of children with chronic hepatitis C circulate non-organ specific autoantibodies. The p revalence of LKM1 is greater than in adults and this could raise probl ems for the treatment of the disease with interferon, The analysis of LKM1 target antigens might help to identify putative cases of ''true'' autoimmune hepatitis with concomitant HCV infection that could benefi t from steroid treatment.