There was debate over the clinical importance of autoantibody positivity in nonalcoholic fatty liver disease (NAFLD) in the absence of autoimmune hepatitis (AIH). In a juvenile cohort with biopsy-proven NAFLD, the research team set out to find the prevalence of autoantibodies and look into the relationship between autoantibodies and the histologic grade of the disease.

A retrospective analysis was conducted at a single facility from 2014 to 2019 on individuals younger or around 21 with biopsy-proven NAFLD. Clinical and analytical data were gathered about 90 days after the liver biopsy. Serum titer ≥1:80 or units ≥20 were considered indicators of autoantibody-positive. After assessing the liver samples for signs of AIH, the NAFLD activity score (NAS) was computed, and scores for steatosis, hepatocyte ballooning, and lobular inflammation were given. In addition, a separate score was assigned to portal fibrosis and inflammation. For binary and continuous outcomes, multivariable logistic regression was utilized.

Seventy-seven participants were eligible for inclusion. Positive results for antinuclear antibodies (ANA), antismooth muscle antibodies (ASMA), antineutrophil cytoplasmic antibodies (ANCA), anti-F-actin antibodies (F-actin), anti-liver kidney microsomal antibodies (LKM) antibodies, or any combination of these antibodies, were seen in 43%, 39%, 19%, 13%, 0%, and 66% of subjects, respectively. Following the elimination of confounding variables, those with positive ANA and aminotransferase (ALT) >80 had 4.6 higher chances of having a NAS ≥5 (P=0.035; 95% CI, 1.12-19.01). 10% to 50% of patients who underwent serial surveillance experienced an autoantibody-positive resolution.

In the absence of AIH, autoantibodies, with the exception of LKM, were often found in the juvenile NAFLD sample. Clinically stratifying pediatric patients with probable NAFLD who test positive for ANA with ALT may assist identify individuals who are more at risk for nonalcoholic steatohepatitis (NASH).