Studies on cellular immunity against bile proteins in primary biliary cirrhosis by the leukocyte migration inhibition test (microdroplet method).

Cellular immunity against human bile proteins was investigated by the leukocyte migration inhibition test (LMIT) with 13 primary biliary cirrhosis (PBC) patients, 10 chronic aggressive hepatitis (CAH) patients and 21 healthy adults. Hepatic bile taken from patients operated on for lithiasis of the biliary tract was fractionated into five fractions with Sepharose 6B gel. A subtoxic dose of each fraction was determined in the healthy adults, and used as the antigen for LMIT. Out of the 5 fractions, only the third fraction led to an LMIT positive response in 8 out of 11 (73%) PBC patients and in 1 out of 10 (10%) CAH patients. The difference between PBC and CAH was significant (p less than 0.005). The remaining 3 PBC patients with LMIT negative responses were all under D-penicillamine treatment. Antibody to each fraction was prepared in rabbits. Using the antibodies after absorption with human serum, the localization of the antigens which were present in each fraction was investigated immunohistochemically using human liver sections. The antigen to the anti-first fraction antibody was detected specifically in the epithelial cells of the bile ducts and the ductules, and the antigen to the anti-third fraction antibody was detected specifically on the membrane of the bile canalicules. The third fraction was fractionated into three fractions by Sephadex G-200 gel. Only the first of the 3 fractions showed an LMIT positive response in 3 PBC patients, and its molecular weight was determined to be about 500,000. It is concluded that PBC patients develop cellular immunity against canalicular-antigen-containing fractions but not ductal-antigen-containing ones.