AMA-NEGATIVE VS AMA-POSITIVE PRIMARY BILIARY CHOLANGITIS: ARE THERE ANY DIFFERENCES?

Introduction and Objectives

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by the presence of antimitochondrial antibodies (AMA) in 90–95% of cases. The clinical features of AMA-negative patients remain incompletely defined.

To compare the clinical characteristics of AMA-positive and AMA-negative PBC patients in a university hospital in Argentina.

Materials and Methods

This retrospective study included 305 patients diagnosed with PBC, divided according to AMA status (238 AMA-positive and 67 AMA-negative). Sociodemographic, clinical, biochemical, and histological variables were analyzed, along with treatment response to ursodeoxycholic acid (UDCA)—assessed using the Paris I, Paris II, Toronto, and Rotterdam criteria—and the use of bezafibrate.

Results

No significant differences were observed in age (56.8 vs. 55 years) or sex (female: 95.5% vs. 95.4%). AMA-negative patients showed slightly lower levels of ALP, AST, GGT, and IgM, without statistical significance, except for total bilirubin (0.82 vs. 1.21 mg/dL; p = 0.004). Fatigue was less frequent in the AMA-negative group (29.9% vs. 45.8%; p = 0.0282), with no differences in pruritus or jaundice. Advanced histological stages (III–IV) were less prevalent among AMA-negative patients (17.9% vs. 36.1%; p = 0.007). Response to UDCA therapy and the use of bezafibrate were comparable between groups.

Conclusions

In this cohort, AMA-negative patients exhibited similar sociodemographic, clinical, and biochemical characteristics to AMA-positive patients. Treatment response to UDCA and the need for bezafibrate were comparable in both groups. Higher levels of total bilirubin, greater fatigue, and a higher proportion of advanced histological stages were observed among AMA-positive patients.

Conflict of interest: None