Clinical diagnosis of primary biliary cirrhosis: a classification based on major and minor criteria.

The presence of antimitochondrial antibodies (AMA) is a sensitive marker for the diagnosis of primary biliary cirrhosis (PBC). Since these antibodies are not specific for PBC, and differentiation of PBC from autoimmune chronic active hepatitis (CAH) has important therapeutic and prognostic implications, additional diagnostic criteria were investigated in 92 patients with AMA. Patients were classified as PBC, CAH, undefined chronic liver disease, or no liver disease by means of three objective methods, and these diagnoses were compared with those of the patients' own physicians. Using internationally accepted strict diagnostic criteria, it was possible to classify 42% of 92 AMA-positive patients. An unbiased computer cluster analysis with 17 variables yielded groups which varied in the severity of the disease, but did not separate clinically different nosological entities. With a diagnostic scheme which uses major and minor criteria for both PBC and CAH, the large majority of patients (86%) were classified as follows: definite PBC (n = 47), probable PBC (n = 20) and no liver disease (n = 12). Seven patients with definite PBC also showed some features of CAH, but there were no patients with only classical CAH. Patients who could not be classified, frequently had very mild liver disease not requiring treatment (6/12), or had not had liver biopsy (6/12). This new diagnostic scheme is promising as it seems to combine sensitivity with specificity for the diagnosis of PBC. If validated in another group of patients with liver disease, it may be helpful for studies on the natural history of the disease and for evaluation of treatments.