Abstract
BACKGROUND: Autoantibodies are frequently positive in adults with nonalcoholic fatty liver disease (NAFLD) without concurrent autoimmune hepatitis (AIH). The clinical significance of this is unknown in children. OBJECTIVE: To determine the prevalence of autoantibody positivity in pediatric NAFLD and to evaluate its association with disease severity. METHODS: Multicenter, retrospective study of patients ≤18 years of age with biopsy-confirmed NAFLD. Descriptive statistics were used and groups were compared using Wilcoxon-Mann Whitney or χ(2) testing, and multivariable logistic regression was used for binary or ordinal outcomes. RESULTS: One hundred and thirty six patients with a median age of 14 years were included. The median body mass index Z-score was 2.5 (interquartile range 2.2, 2.6). Positive antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA), anti-liver-kidney microsomal antibody, or any combination of autoantibodies were observed in 22%, 14%, 0%, and 33% of patients, respectively. The proportion of patients with a steatosis score ≥2 was significantly higher in those with positive ANA (P = .045). In the multivariable regression analysis, positive ANA was associated with increased odds of steatosis score ≥2 (odds ratio, 5.91; 95% confidential interval, 1.50-23.26), after controlling for potential confounders. No other significant histology differences were seen between the groups. CONCLUSIONS: Positive ANA and ASMA are common in children with NAFLD; however, anti-LKM positivity is not. ANA positivity is associated with more severe steatosis.