The vast majority of overweight or obese children with suspected nonalcoholic fatty liver disease (NAFLD) will test negative for other causes of chronic liver disease, new research indicates. "Nonetheless, NAFLD remains a diagnosis of exclusion, and key conditions that require specific treatments must be ruled out in the workup of patients with suspected NAFLD," say Dr. Marialena Mouzaki from Cincinnati Children's Hospital Medical Center in Ohio and colleagues in a report in Pediatrics. Guidelines recommend that children with overweight or obesity and chronically elevated serum alanine aminotransferase (ALT) levels be evaluated for NAFLD and undergo testing to rule out other causes of liver disease. To determine how common other causes of NAFLD may be, Dr. Mouzaki and colleagues studied 900 overweight or obese children (median age, 13 years; 63% boys, 26% Hispanic) referred for suspected NAFLD. About three quarters of the children had severe obesity. The median ALT level of the cohort at the initial visit was 64 U/L. The ALT level was normal in 5% of children, 1 to 2 times the upper limit of normal in 29%, and more than 2 times the ULN in 66%. Among the 347 children with biopsy-confirmed NAFLD, 160 (46%) had nonalcoholic steatohepatitis. Of the 900 patients with suspected NAFLD, only 19 (2%) were diagnosed with other chronic diseases. Three had celiac disease, 11 had thyroid dysfunction requiring treatment, three had alpha-1 antitrypsin deficiency, one had Hodgkin's lymphoma and one had hemophagocytic lymphohistiocytosis. No patient was diagnosed with autoimmune hepatitis (AIH). This finding is in contrast to a recent study that found 11 of 255 (4%) overweight or obese children referred for suspected NAFLD had evidence of AIH, rendering AIH the second most common diagnosis, after NAFLD, in that population. Dr. Mouzaki and colleagues say these discrepant findings may potentially reflect differences in race and ethnicity between the study cohorts and should be investigated further. "In the meantime, it is important to continue testing for AIH in patients with suspected NAFLD because early identification and treatment of AIH is important for future outcomes," they write. There were also no cases of Wilson disease or viral hepatitis in their cohort, although testing for these possibilities remains important, they say. "When caring for patients with suspected NAFLD, it remains critical to evaluate for concurrent other chronic diseases that may mimic or coexist with NAFLD because some of these conditions require specific pharmacotherapy and/or may progress rapidly without appropriate treatment. In the future, the cost-effectiveness of this approach will need to be investigated," the study team concludes. Funding for the study was provided by the National Institutes of Health. The authors have no relevant disclosures. —Reuters Staff Source
