Serum ferritin levels lack diagnostic accuracy for liver fibrosis in patients with nonalcoholic fatty liver disease.

ABSTRACT

BACKGROUND & AIMS: Series studies have associated increased serum levels of ferritin with liver fibrosis in patients with nonalcoholic fatty liver disease. We aimed to determine the accuracy with which measurements of serum ferritin determine the presence and severity of liver fibrosis, and whether combining noninvasive scoring systems with serum ferritin analysis increases the accuracy of diagnosis of advanced liver fibrosis. METHODS: We performed a retrospective analysis of data from 1014 patients with liver biopsy-confirmed nonalcoholic fatty liver disease. Three cut points of serum ferritin level, adjusted for sex, were established based on receiver operating characteristic curve analysis: 1.0-, 1.5-, and 2.0-fold the upper limit of normal. Three multiple logistic regression models were created to determine the association of these cutoff values with liver fibrosis, adjusting for age, sex, race, diabetes, body mass index, and level of alanine aminotransferase. RESULTS: A greater proportion of patients with increased serum levels of ferritin had definitive nonalcoholic steatohepatitis and more-advanced fibrosis than patients without increased levels. In all models, serum level of ferritin was significantly associated with the presence and severity of liver fibrosis. However, for all 3 cutoff values, area under the receiver operating characteristic curve values were low (less than 0.60) for the presence of fibrosis or any stage of liver fibrosis; ferritin level identified patients with fibrosis with 16%-41% sensitivity and 70%-92% specificity. The accuracy with which noninvasive scoring systems identified patients with advanced fibrosis did not change with inclusion of serum ferritin values. CONCLUSIONS: Although serum levels of ferritin correlate with more-severe liver fibrosis, based on adjusted multiple logistic regression analysis, serum ferritin levels alone have a low level of diagnostic accuracy for the presence or severity of liver fibrosis in patients with nonalcoholic fatty liver disease.