A new five-factor score may help clinicians identify alcohol-driven steatotic liver disease and decide when confirmatory testing is needed.
A new blood test score built from routine clinical data could help clinicians detect when steatotic liver disease is being driven by alcohol use that may otherwise go undisclosed, according to new research.
The tool, the MetALD-ALD Prediction Index, or MAPI, was designed to distinguish metabolic dysfunction-associated steatotic liver disease from steatotic liver disease in which excessive alcohol use is contributing to injury.
Details of the research have been published in Gastroenterology.
Investigators said the score used five variables already available in standard care settings, including sex, mean corpuscular volume, gamma-glutamyl transferase, high-density lipoprotein cholesterol and haemoglobin A1c, making it immediately applicable in primary care and hepatology practice.
Senior author Professor Rohit Loomba, from the University of California San Diego School of Medicine and UC San Diego Health, said the score offered a practical way to uncover alcohol-related liver injury that may be missed in routine assessment.
“By improving how we classify liver disease, we can help patients achieve better long-term health outcomes,” he said.
The authors said that better classification could support earlier intervention, more targeted counselling and more personalised treatment decisions.
The study addressed a common clinical problem in steatotic liver disease, where metabolic risk factors such as obesity and type 2 diabetes frequently coexist with alcohol exposure.
Although accurate classification is increasingly important under the newer steatotic liver disease nomenclature, alcohol intake was still often assessed through self-report, which is vulnerable to under-reporting because of stigma, fear of consequences and time constraints in clinical encounters.
To develop the model, researchers analysed 503 adults with overweight or obesity and steatotic liver disease from the prospective San Diego Liver Study. All participants underwent advanced liver phenotyping, including magnetic resonance imaging and magnetic resonance elastography, alongside phosphatidyl ethanol testing. PEth, a direct blood biomarker of recent alcohol consumption, was incorporated into the outcome definition to reduce misclassification from under-reported alcohol use.
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The researchers externally validated the score in an independent Swedish cohort, HERALD, comprising 1777 adults from primary and secondary care with available PEth measurements. In the derivation cohort, MAPI achieved an area under the receiver operating characteristic curve of 0.76 for detecting PEth-defined MetALD-ALD.
In the validation cohort, the AUROC was 0.75, indicating similar discriminatory performance in a separate healthcare setting.
Investigators reported that MAPI outperformed commonly used indirect alcohol biomarkers, including gamma-glutamyl transferase alone, mean corpuscular volume alone and the AST/ALT ratio.
Although its performance was similar to the established ALD/non-alcoholic fatty liver disease index in some analyses, MAPI was the top-performing marker overall and was developed specifically to identify the newer alcohol-related steatotic liver disease categories, including MetALD.
The authors said the score could be especially useful where PEth testing is unavailable, too costly or impractical for broad screening. In that setting, MAPI could serve as a first-line risk stratification tool to identify patients who warrant confirmatory PEth testing.
In clinical environments where PEth is available, the score may help target testing toward patients classified as having MASLD on history alone, but who remain at risk of alcohol-related disease because of under-reporting.
First author Dr Federica Tavaglione said the goal was to create a clinically practical tool that could be implemented without adding cost or complexity.
“These lab values are already part of standard care, so MAPI can be implemented immediately without adding cost or complexity for clinics,” she said.
The findings also have implications beyond day-to-day care. The authors suggested MAPI may be useful in observational cohorts and clinical trials that do not include PEth measurements, allowing researchers to better identify participants with likely MetALD or alcohol-associated liver disease retrospectively.
The study has limitations. The cohorts did not include structured assessment of drinking in the week immediately before blood sampling, meaning episodic heavy drinking may not have been fully captured.
The analysis also relied on single time-point PEth measurements, which may not reflect longer-term fluctuations in alcohol intake. In addition, the score still needed evaluation in patients with cirrhosis and in longitudinal studies assessing prognostic value over time, the researchers noted.
However, they said the study added to growing evidence that alcohol-related liver injury is frequently missed when steatotic liver disease was classified on self-reported consumption alone.
“MAPI may serve as a valuable tool to help clinicians identify individuals at risk for MetALD-ALD who would benefit from confirmatory PEth testing, ultimately improving diagnostic accuracy and guiding appropriate clinical management,” the researchers concluded.
“Finally, MAPI may enable retrospective application in observational cohort studies without PEth data, as well as in clinical trials.”
