Liver disease: new blood-test tool reveals hidden alcohol-related cases

Researchers developed MAPI, a score using five routine blood measures to distinguish alcohol-related liver disease from metabolic causes; it performed with AUROC ≈0.75 in both US and Swedish datasets.

A multinational research team has described a new screening tool called MAPI that uses routine laboratory values to identify when a patient’s fatty liver disease involves alcohol rather than only metabolic factors. The score combines five measures already collected in standard care and does not require extra blood draws or questionnaires. The model was developed using data from adults enrolled in the San Diego Liver Study and was externally validated in a larger Swedish cohort. The work was reported in the journal Gastroenterology. Key findings: - The MAPI model uses five routine variables: sex, mean corpuscular volume (MCV), gamma-glutamyl transferase (GGT), HDL cholesterol, and hemoglobin A1c (HbA1c). - Development data came from 503 overweight or obese adults with fatty liver disease; external validation used nearly 1,800 individuals in Sweden. - MAPI scored about 0.76 (US) and 0.75 (Sweden) on the AUROC measure, indicating consistent discrimination between alcohol-involved and metabolic-driven cases. - The tool includes cut-offs reported in the study: a score below 0.09 strongly lowers the likelihood of alcohol involvement, 0.25 was the study’s primary threshold, and a score above 0.33 showed high specificity in identifying alcohol-related cases. - Researchers used phosphatidylethanol (PEth) testing in the study to classify recent alcohol use; PEth is accurate but less widely available and more costly than the routine tests MAPI uses. - The authors report that MAPI outperformed several commonly used indirect alcohol biomarkers and can detect overlapping cases where metabolic factors and alcohol both play a role. Summary: MAPI distinguished alcohol-involved liver disease from metabolic-driven disease with consistent performance across U.S. and Swedish populations and compared favorably with other indirect biomarkers. The study notes that MAPI relies on tests already performed in routine care, and the authors say it could be implemented without additional blood draws or new assays.