# Liver Maximum Capacity (LiMAx) Test Is a Promising Tool to Predict Fibrosis and Cirrhosis in Chronic Liver Disease: A Systematic Review

## TL;DR

The LiMAx test is a non-invasive method that accurately predicts liver fibrosis and cirrhosis in patients with chronic liver disease.

## Contribution

The LiMAx test shows superior diagnostic accuracy compared to existing methods for predicting liver disease progression and mortality.

## Key findings

- LiMAx outperforms other tests like TE, FIB-4, and APRI in predicting 90-day mortality (AUROC=0.82).
- LiMAx has a strong negative correlation with liver histopathology (r=-0.75).
- LiMAx is particularly effective in detecting cirrhosis (AUROC=0.92).

## Abstract

Patients affected with chronic liver disease (CLD) are increasing and our ability to manage them is hindered by the lack of a simple and accurate test for measuring the liver function. LiMAx is a novel, non-invasive tool that measures the metabolic capacity of hepatocytes by measuring the ratio of 13CO2 to 12CO2 exhaled following the administration of isotope-labelled methacetin. This systematic review assessed the ability of LiMAx to diagnose and stage steatosis and fibrosis and predict 90-day mortality in CLD. Literature search was carried out using Embase and Medline accessed via Ovid, Web of Science, and Cochrane Library. The inclusion criteria were case-control or cohort studies in all languages. Statistical analysis for the diagnostic accuracy of LiMAx and the diagnostic accuracy of other available methods for clinically relevant milestones in CLD was carried out by pooling the area under the receiver operating characteristic curve (AUROC) and correlation coefficients. A total of seven studies met the inclusion criteria and data were extracted into Microsoft Excel tables with a total number of 1623 participants. LiMAx performed significantly better than transesophageal echocardiography (TE), Fibrosis-4 (FIB-4) test, aspartate transaminase to alanine transaminase ratio (AAR), spleen size and aspartate aminotransferase-to-platelet ratio index (APRI) at predicting 90-day mortality (AUROC=0.82). LiMAx is superior in detecting cirrhosis (AUROC=0.92) and at identifying fibrosis for patients with non-MASLD (metabolic dysfunction-associated steatotic liver disease) aetiology. Furthermore, LiMAx had the strongest (negative) correlation with liver histopathology (r=-0.75). It was found that the LiMAx test is a promising point-of-care approach for the detection of cirrhosis and fibrosis. However, large-scale studies across all liver aetiologies and stages are necessary to confirm the utility of LiMAx in clinical practice.