Clinical correlates of histopathology in pediatric nonalcoholic steatohepatitis (NASH)

Background & Aims - Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in American children. Noninvasive means to discriminate between NAFLD and nonalcoholic steatohepatitis (NASH) might diminish requirement for liver biopsy or predict those at increased risk for progression. Methods - Data obtained prospectively from children (aged 6-17 yrs) enrolled in the NASH Clinical Research Network (NASH CRN) were analyzed to identify clinical-pathological correlates of pediatric NAFLD. All participants underwent liver biopsy within 6 months of clinical data that was reviewed by a central pathology committee. Results - 176 children (mean age 12.4 years, 77% male) were eligible for inclusion. Using ordinal logistic regression analysis, increasing AST (OR 1.017 per U/L, 95% CI 1.004-1.031) and GGT (OR 1.016 per U/L, 95% CI 1.000-1.033) were independently associated with increasing severity of NASH. Increasing AST (OR 1.015 per U/L, 95% CI 1.006-1.024), increasing white blood cell count (OR 1.22 per 1000/mm³, 95% CI 1.07-1.38), and decreasing hematocrit (OR 0.87 per %, 95% CI 0.79-0.96) were independently associated with increasing severity of fibrosis. Area under the ROC for a model with AST and ALT was 0.75 (95% CI=0.66-0.84) and 0.74 (95% CI 0.63-0.85) for distinguishing steatosis from more advanced forms of NASH and bridging fibrosis from lesser degrees of fibrosis, respectively. Conclusions - Certain components of routine laboratory tests are predictive of NAFLD pattern and fibrosis severity, but do not have adequate discriminate power to replace liver biopsy in evaluating pediatric NAFLD.