Primary biliary cirrhosis is a chronic liver disease, characterized by the destruction of the epithelial cells of the sublobular, interlobular and septal bile ducts and with the development of cirrhosis. The presence of anti-mitochondrial antibodies against the subunits of mitochondrial 2-oxoacids dehydrogenases is characteristic for patients with primary biliary cirrhosis. The aim of this work was to study the effect of anti-mitochondrial antibodies upon activity of the isolated mitochondrial pyruvate dehydrogenase complex after the incubation with serum from patients with primary biliary cirrhosis. Group of patients and methods. The activity of the purified bovine pyruvate dehydrogenase complex was studied spectrophotometrically in presence of the serum (1 : 1000) from five patients with primary biliary cirrhosis and from ten disease free controls. Results. The activity of the pyruvate dehydrogenase was decreased after incubation with the serum from patients with primary biliary cirrhosis. No similar inhibitory effect was found after incubation with serum from controls. Discussion. The inhibitory effect of the anti-mitochondrial antibodies upon activity of pyruvate dehydrogenase may broaden the spectrum of diagnostic methods in patients with primary biliary cirrhosis. Further investigations are necessary to assess the possible application of this method for monitoring of changes during the course of the disease and for assignation of the disease prognosis.

        Key words: Primary biliary cirrhosis - Anti-mitochondrial antibodies - Pyruvate dehydrogenase complex