Comparison of diagnostic accuracy of screening tests ALT and ultrasound for pediatric non-alcoholic fatty liver disease

Abstract

Alanine aminotransferase (ALT) and ultrasound (US) are the most commonly used tools for detecting non-alcoholic fatty liver disease (NAFLD). No direct comparison of these two modalities in children exists. We aimed to compare head-to-head the diagnostic accuracy of ALT and US and their combination for detecting NAFLD in children with obesity. Ninety-nine children with severe obesity underwent simultaneous serum-ALT and abdominal ultrasound (US steatosis score 0–3). Proton magnetic resonance spectroscopy was used as reference standard for detecting steatosis/NAFLD. ROC curve analyses were performed to determine diagnostic performance and to determine optimum screening cut-points aiming for a specificity ≥ 80%. The area under the ROC (AUROC) of ALT and US were not significantly different (0.74 and 0.70, respectively). At the optimal ALT threshold (≥40 IU/L), sensitivity was 44% and specificity was 89%. At the optimal US steatosis score (≥ 2), sensitivity was 51% and specificity was 80%. Combining ALT and US did not result in better accuracy than ALT or US alone. Conclusion : ALT and US have comparable and only moderate diagnostic accuracy for detecting hepatic steatosis in children with obesity. A stepwise screening strategy combining both methods does not improve diagnostic accuracy. What is Known: • Alanine aminotransferase ( ALT ) and ultrasound ( US ) are the most commonly used tools for detecting non-alcoholic fatty liver disease ( NAFLD ) . • ALT and ultrasound have mediocre accuracy in detecting steatosis in children with obesity. What is New: • In a head-to-head comparison, the difference in diagnostic accuracy of ALT and ultrasound in detecting steatosis is not significant. • A stepwise screening strategy combining both methods does not improve diagnostic accuracy .

A sociodemographic, anthropometric and lifestyle‐based prediction score for screening children with overweight and obesity for hepatic steatosis: The HEPAKID index

“…In addition, the majority of studies in children with biopsy-proven or MRI-diagnosed HS report that ALT levels and ultrasound techniques only show moderate diagnostic accuracy in terms of detecting HS in children, and that combining them leads to no improvement in sensitivity. 48,49 Other authors propose blood ALT concentrations of >35 IU/L as indicative of HS. However, while this cut-off has a high specificity (between 92% and 94%) it has only low sensitivity (between 24% and 48%).…”

Protective Effect of a Mixture of Astragalus membranaceus and Lithospermum erythrorhizon Extract against Hepatic Steatosis in High Fat Diet‐Induced Nonalcoholic Fatty Liver Disease Mice

“…Among them, especially ALT, is a sensitive biomarker as an indicator associated with NAFLD [49]. In many clinical studies on NAFLD, an increased level of ALT has been considered as an independent predictor [50]. It is also generally accepted that GGT, which is an enzyme abundant in the liver, is elevated as a result of obesity and liver damage, and thus regarded as one of the predictors of liver mortality [51].…”

Perspectives on youth‐onset nonalcoholic fatty liver disease

“…However, in children it has low sensitivity and specificity, and based on the available evidence, a 2014 systematic review concluded that the use of ultrasound for NAFLD diagnosis or grading in youth is not recommended 89 . In a study of children with obesity, with MRI as the reference ‘gold standard’ method, ALT and ultrasound sensitivity performed similarly in detecting NAFLD cases (44% vs 51%, respectively) and the concomitant use of both methods for screening didn't improve the diagnostic accuracy to detect NAFLD 90 …”