Abstract
<jats:p>Background. Children with Down syndrome (DS) are at increased risk of non-alcoholic fatty liver disease (NAFLD), which is now referred to as metabolic dysfunction-associated steatotic liver disease, especially in the presence of obesity. Liver biopsy is still the best diagnostic approach, but noninvasive alternatives are needed. Cytokeratin 18 (CK-18) has shown promise as a biomarker for NAFLD. The purpose was to evaluate the diagnostic utility of CK-18 for detecting NAFLD in children with DS. Materials and methods. This case-control study included 80 DS children aged 3–18 years, divided into obese and non-obese groups. CK-18 levels were measured using enzyme-linked immunosorbent assay, and abdominal ultrasound was performed through one sonographer assessment using US device Aplio 500 with convex and linear probe to assess hepatic steatosis. NAFLD grading (0–3) correlated with anthropometric data, liver enzymes, lipid profile, and CK-18 levels. Statistical analysis evaluated the predictive value and diagnostic performance of CK-18. Results. CK-18 levels were significantly increased in DS children with NAFLD compared to healthy controls (p < 0.001) and positively correlated with body mass index Z-scores, cholesterol, and alanine aminotransferase. CK-18 showed excellent diagnostic accuracy for NAFLD (AUC = 0.912), with a cutoff ≥ 494.35 pg/ml yielding 93.6 % sensitivity and 87.9 % specificity. It was also effective in distinguishing between NAFLD grades and control, particularly for grade 1 (AUC = 0.919) and grade 2 (AUC = 0.909). Conclusions. CK-18 is a highly sensitive and specific noninvasive biomarker for NAFLD in children with DS. It can aid in rapid detection and follow-up of liver involvement, potentially decreasing the requirement for invasive liver biopsies.</jats:p>