Reevaluating the clinical course of AMA-positive patients with normal liver enzymes: A large retrospective cohort study.

INTRODUCTION AND

OBJECTIVES

The long-term clinical significance of anti-mitochondrial antibody (AMA)-positive patients with normal liver enzymes remains unclear. Despite increasing detection of AMA positivity in asymptomatic individuals, clinicians lack evidence-based protocols for long-term surveillance, and guidelines offer no clear recommendations. This study, the largest of its kind, investigates the natural history, prognostic implications, and risk factors for disease progression in this population.

MATERIALS AND

METHODS

We conducted a retrospective cohort study using a national healthcare database to identify adults (aged 18 years or older) with a positive AMA and normal alkaline phosphatase (ALP) levels between 2002 and 2023. Demographics, laboratory data, and liver-related outcomes were assessed. Multivariate logistic and Cox regression models were used to evaluate predictors of primary biliary cholangitis (PBC), cirrhosis, and hepatic complications.

RESULTS

Among 1018 patients (median follow-up 6.3 years (IQR 2.5-11.5), 76 (7.5 %) developed PBC and 30 (2.9 %) progressed to cirrhosis. Liver-related complications were infrequent: esophageal varices (1.1 %), ascites (1.8 %), hepatocellular carcinoma (0.2 %), and liver transplantation (0.1 %). Higher AMA titers were strongly associated with increased risk of PBC, cirrhosis, and complications, showing a clear titer-dependent gradient. Longitudinal analysis also demonstrated titer-associated increases in ALP and bilirubin over time.

CONCLUSIONS

AMA-positive individuals with normal liver enzymes typically experience a benign clinical course. However, high AMA titers identify a subgroup at increased risk for progression to PBC and advanced liver disease. These findings underscore the importance of risk-stratified surveillance strategies in clinical practice, guiding healthcare professionals in the management of their patients.