ANTIMITOCHONDRIAL ANTIBODY-NEGATIVE PRIMARY BILIARY-CIRRHOSIS

Objectives: We reviewed our experience with patients who had biochemic al and histological features of primary biliary cirrhosis in the absen ce of antimitochondrial antibodies (AR;IA) to better understand this v ariant of the syndrome. Methods: During the period between 1976 to 199 2, 597 patients with clinical and histological features of primary bil iary cirrhosis were seen at the Mayo Clinic. Thirty-five (5.8%) of the se patients were negative for antimitochondrial antibody and had norma l cholangiographic studies. The records of these patients were reviewe d for this study. Results: No difference was found between the two gro ups with respect to age, gender, or biochemical features. IgM and gamm a-globulin levels were higher in the antimitochondrial antibody-positi ve than the antimitochondrial antibody-negative patients. What is more important, 96% of the AMA-negative patients who could be tested were positive for antinuclear antibody or anti-smooth-muscle antibodies. Th ese tests were positive in only 56% of the antimitochondrial antibody- positive group (p < 0.05). The response of five of these patients to u rsodeoxycholic acid appeared comparable to the response seen in antimi tochondrial antibody-positive patients. Conclusions: Patients with his tological features of primary biliary cirrhosis, whether antimitochond rial antibody positive or negative, are quite comparable with respect to clinical and biochemical features. Other autoantibodies, such as an tinuclear or anti-smooth-muscle antibodies, are more common in the ant imitochondrial antibody-negative group. These two conditions might be part of a spectrum that has been termed ''autoimmune cholangitis'' and that is characterized by chronic cholestasis, histological features o f chronic nonsuppurative destructive cholangitis, and the presence of any of a variety of serum autoantibodies.