[Anti-actin antibodies in acute viral hepatitis A in children]

Hepatitis A Virus (HAV) infection has been proposed as a possible trigger of autoimmune hepatitis type I. We have previously reported the presence of anti-actin antibodies en protracted hepatitis A. At present the presence of anti-actin antibodies in acute uncomplicated hepatitis A is unknown. The aim of this study was to evaluate the incidence and persistence of anti-actin antibodies un children with acute hepatitis A.

38 patients, 21 female and 17 male, with mean age of 6.5 years (range 2-13 years) were included. All patients were anti HAV IgM positive. The patients were clinically controlled and laboratory determinations such as ALT/AST, gammaglobulin, gamma GT, nuclear, smooth muscle (anti-actin specificity) and liver-kidney-microsome type I (anti-LKM) antibodies, were evaluated at admission and at the first, third and fifth month. Anti-actin antibodies were determined by indirect immunofluorescense (IIF) on rat kidney, stomach and liver sections and also on monolayers of cultured fibroblasts. Titers higher than 1/40 were considered positive.

18 patients (47.3%) were anti-actin positive in the first determination (titers 1/40 and 1/80). In 4 patients (12.9%) these antibodies remained positive up to one month. All patients were negative 5 months after the onset of illness. ANA and anti-LKM were negative in all cases.

1) This data demonstrate the presence of anti-actin antibodies in children with uncomplicated HAV hepatitis. 2) The antibodies remained positive for a short period of time. 3) Titers were lower than in autoimmune hepatitis type I. 4) Taken together these results suggest that anti-actin antibodies would be an expression of non specific stimulation of lymphocyte B.