ANTIACTIN ANTIBODIES IN SERA FROM PATIENTS WITH AUTOIMMUNE LIVER-DISEASES AND PATIENTS WITH CARCINOMAS BY ELISA

Smooth muscle antibodies (SMA) were initially detected in sera of pati ents with chronic active hepatitis (CAH). Subsequently, their presence was demonstrated in a wide variety of other diseases. SMA are a mixtu re of antibodies directed towards different cytoskeletal antigens. Ser a with high titers of anti-actin antibodies (AAA), a subgroup of SMA, are most frequently found among patients with autoimmune chronic activ e hepatitis (CAH) and, to a lesser extent, among patients with primary biliary cirrhosis (PBC) and other diseases. It is therefore establish ed that AAA are a reliable marker to autoimmune CAH. The purpose of th is study was to determine the titer of AAA in sera of patients with li ver, autoimmune diseases and carcinomas, using the enzyme-linked immun oabsorbant assay (ELISA) method. The results were expressed as the opt ical density (OD) of the examined sera divided by the OD of a sera fro m a healthy control (presented as percentages +/- standard deviation). Sera of 33 patients with cirrhosis, nine patients with autoimmune CAH , fifteen patients with non-autoimmune CAH, eight patients with PBC, 3 0 patients with Sjogren's syndrome, 60 patients with SLE, 142 patients with carcinomas of different kinds, and 34 healthy donors were examin ed for the presence of AAA by ELISA. Statistically significant (P < 0. 003) higher titers of AAA were detected in patients with autoimmune CA H (57 +/- 23%) compared with the control group and to other groups of diseases. AAA titers in non-autoimmune CAH were not significantly high er compared to the control group. High titers of AAA were detected in 67% of the patients with autoimmune CAH, as compared with other diseas es in which only up to 13% of the patients exhibited AAA positivity. C onclusion: existence of higher levels of AAA noted in 67% of the patie nts with autoimmune CAH with regard to other groups of diseases, empha sizes the value of AAA as sensitive and specific markers, capable of c haracterizing the patients with autoimmune chronic active hepatitis.