Clinical evaluation of primary biliary cirrhosis in Chinese patients without serum anti-mitochondrial antibody.

BACKGROUND

Primary biliary cirrhosis (PBC), a chronic, progressive, cholestatic liver disease characterized by frequent presence of the anti-mitochondrial antibody (AMA), is rarely seen in the Asian population. Whether or not the presence of AMA alters the clinical, serological and histological features of the disease remains unclear.

METHODS

During the 25-year period from 1972 to 1996, 71 Chinese patients with PBC who were diagnosed clinically and/or histologically were reviewed. Seventeen (24%) of them repeatedly tested negative for serum AMA. Clinical, biochemical, immunological, histological data and treatment response to ursodeoxycholic acid were compared between PBC patients with positive and negative serum AMA.

RESULTS

Mean serum immunoglobulin M (IgM) level was significantly lower in AMA-negative PBC patients when compared with AMA-positive PBC patients (422 +/- 163 vs. 651 +/- 412 mg/dL, p = 0.042). Serum anti-nuclear antibodies (ANA) were positive in 93% of the AMA-negative PBC patients, a significantly higher percentage when compared with the 66% of AMA-positive patients (p = 0.048). There were no significant differences with regard to age, sex, clinical manifestations, liver biochemistries, histological findings, survival and response to 1-year ursodeoxycholic acid treatment between the AMA-negative and AMA-positive patients. Univariate logistic regression analysis showed relatively lower serum IgM levels, positive serum ANA and anti-centromere type ANA were significant predictive factors to negative serum AMA in PBC patients (p = 0.035, 0.044 and 0.029, respectively). Multi-variate analysis revealed relatively lower serum IgM levels were the only independent significant predictor to negative serum AMA in PBC patients (p = 0.015).

CONCLUSIONS

Twenty-four percent of Chinese patients with PBC were negative for serum AMA. AMA-negative PBC patients were characterized by relatively lower serum IgM levels and a higher rate of positive serum ANA.