Prediction of primary biliary cholangitis among health check-up population with anti-mitochondrial M2 antibody positive.

Background: Anti-mitochondrial M2 antibody (AMA-M2) is a specific marker for primary biliary cholangitis (PBC) and it could be also presented in non-PBC individuals.

Methods: A total of 72173 Chinese health check-up individuals tested AMA-M2, of which non-PBC AMA-M2 positive individuals were performed follow-up. Baseline data of both clinical characteristics and laboratory examinations were collected in all AMA-M2-positive individuals. Least absolute shrinkage and selection operator (LASSO) regression was performed to investigate the potential variables for developing PBC.

Results: A total of 2333 individuals were positive with AMA-M2. Eighty-two individuals had a medical history of PBC or fulfilled the diagnostic criteria of PBC at baseline, and 2076 individuals were non-PBC. After a median follow-up of 6.6 years, 0.6% developed PBC, with an accumulative 5-year incidence rate of 0.5%. LASSO regression showed that levels of alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), immunoglobulin M (IgM), eosinophilia proportion (EOS%), gamma globulin percentage, and hemoglobin (HGB) were potential variables for developing PBC. Multivariate Cox regression is used to construct a predictive model based on 7 selected variables, and time-dependent receiver operating characteristic analysis showed that the area under the curve of the prediction model at 3, 5, and 10 years were, respectively, 1.000, 0.875, and 0.917.

Conclusion: This study offers insights into the onset of PBC among individuals who tested positive for AMA-M2 during routine health check-ups.. The prediction model based on ALP, GGT, IgM, EOS%, gamma globulin percentage, HGB, and sex has a certain predictive ability for the occurrence of PBC in this population.