ANTIMITOCHONDRIAL (PYRUVATE-DEHYDROGENASE) ANTIBODIES IN LEPROSY

Sera from 69 patients with leprosy but without liver involvement were assayed for the presence of mitochondrial pyruvate dehydrogenase (PDH) -specific autoantibodies by enzyme-linked immunoabsorbent assay (ELISA ), immunoblotting using PDH as an antigen and by enzymatic inhibition test. Twenty-seven of the leprosy serum samples (39.1%) were found to react with PDH by ELISA. However, unlike sera from primary biliary cir rhosis (PBC) patients, none of these were able to inhibit the PDH enzy matic activity. By immunoblotting, it was found that only 2 of the 27 positive sera recognized the 74-kD protein of the PDH complex, which i s recognized by sera of most PBC patients. The antimitochondrial antib odies in lepra most probably recognize different epitopes than those i n PBC. These findings may indicate that anti-PDH autoantibodies in pat ients with leprosy may arise by polyclonal B cell stimulation and may represent natural anti-PDH autoantibodies.