Using liver fatty acid binding protein as a diagnostic marker for metabolic dysfunction and associated steatotic liver disease (MASLD) in Egyptian patients: a case-controlled study

Abstract Background Metabolic dysfunction-associated steatotic liver disease ( MASLD) is the leading cause of chronic liver disease, which may progress to cirrhosis and liver cancer. Even though hepatic biopsy is the benchmark for diagnosis, non-invasive techniques are becoming more popular for MASLD diagnosis, progression tracking, and treatment monitoring. Recently, hepatic injury and fibrosis have been linked to liver fatty acid-binding protein (L-FABP). This study assesses the diagnostic utility of L-FABP in Egyptian patients with MASLD. Methods This case-control study included 80 participants: 20 age- and sex-matched healthy controls and 60 patients with MASLD. Patients from Menoufia University Hospitals were enrolled between October 2024 and June 2025. Each patient underwent clinical evaluation, laboratory testing, and measurement of serum L-FABP by enzyme-linked immunosorbent assay (ELISA). Fibroscan with controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), as well as abdominal ultrasonography, were performed. Fibrosis-4 Index (FIB-4), NAFLD fibrosis score, and aspartate aminotransferase to platelet ratio index (APRI) were calculated. Results Patients with MASLD had significantly greater serum levels of L-FABP than controls (p < 0.001). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), APRI, FIB-4, and Nonalcoholic Fatty Liver Disease (NAFLD) fibrosis scores were significantly correlated with L-FABP. L-FABP levels and steatosis grade, however, did not significantly correlate. An L-FABP cut-off of 4.05 ng/mL was shown to have acceptable diagnostic accuracy for MASLD (AUC = 0.90, 95% sensitivity). An L-FABP cut-off of 6.5 ng/mL demonstrated excellent accuracy (AUC = 0.963) for the prediction of liver fibrosis. Multivariate logistic regression analysis identified serum L-FABP as an independent factor associated with the presence of liver fibrosis (p = 0.043). Conclusion Serum L-FABP is a potential noninvasive biomarker for the diagnosis of MASLD and for evaluating liver fibrosis. It correlates well with the degree of liver injury and fibrosis but not with the degree of steatosis.