Background: The severity of liver fibrosis is known to be a good indicator for surveillance, and for determining the prognosis and optimal treatment of nonalcoholic fatty liver disease (NAFLD). However, it is virtually impossible to carry out liver biopsies in all NAFLD patients. The purpose of this study was to investigate the clinical usefulness of measuring the platelet count for predicting the severity of liver fibrosis in a large retrospective cohort of Japanese patients with NAFLD.
Methods: A total of 1,048 patients with liver-biopsy-confirmed NAFLD seen between 2002 and 2008 were enrolled from nine hepatology centers in Japan. Laboratory evaluations were performed for all patients.
Results: A linear decrease of the platelet count with increasing histological severity of hepatic fibrosis was revealed. The area under the receiver operating characteristic curve estimating the diagnostic performance of the platelet count for hepatic fibrosis Stage 3 was 0.774 (optimal cutoff value, 19.2 × 10(4)/μl; sensitivity, 62.7%; specificity, 76.3%), and that for Stage 4 was 0.918 (optimal cutoff value, 15.3 × 10(4)/μl; sensitivity, 80.5%; specificity, 88.8%).
Conclusions: The platelet count may be an ideal biomarker of the severity of fibrosis in NAFLD patients, because it is simple, easy to measure and handle, cost-effective, and accurate for predicting the severity of fibrosis. Furthermore, by using the platelet count cutoff value validated in our multiple large trials, efficient recruitment of NAFLD patients may be facilitated.