Two strategies using transient elastography to diagnose

and exclude advanced fibrosis in NAFLD patients were evaluated: (1) use a single cutoff with the best overall sensitivity and specificity; (2) use two cutoffs with high sensitivity and specificity. If liver biopsies were reserved for patients with LSM of at least 8.7 kPa, only 79 (32.1%) would require the procedure. Eight (4.8%) patients with F3 disease and one (0.6%) patient with cirrhosis would be missed (Table 2). When two cutoffs were used, 148 (60.2%) patients had LSM below the low cutoff of 7.9 kPa, and the negative predictive value was 96.6% (95% CI, 93.7%–99.5%) (Table 2, Fig. 3). Fifty-eight (23.6%) patients had LSM above the high cutoff of 9.6 kPa, and the positive predictive value was 72.4% (95% CI, 60.9%–83.9%). If liver biopsies were performed only in patients with LSMs between 7.9 and 9.6 kPa, 40 (16.3%) patients required

the procedure. Five (3.4%) Birinapant chemical structure patients with F3 disease would Fer-1 be missed, and 16 (27.6%) patients without advanced fibrosis would be misclassified. Alternatively, if liver biopsies were performed in all patients with LSM above 7.9 kPa, 98 (39.8%) would require the procedure. In this large prospective cohort of NAFLD patients, transient elastography had high accuracy in detecting advanced fibrosis and cirrhosis. Successful measurement could be obtained in more than 97% of patients with BMI below 30 kg/m2 and 75% of obese patients. LSM was not affected by hepatic steatosis, necroinflammation, or obesity. Most discordance between transient elastography and histology

occurred in patients with short liver biopsy lengths and mild or no fibrosis. In addition, transient elastography had superior performance to other noninvasive biochemical tests in diagnosing advanced fibrosis and cirrhosis. Transient elastography has been validated in chronic viral hepatitis, cholestatic liver disease, and alcoholic liver disease.11, 21–24 According to a meta-analysis of nine studies, the pooled estimates of sensitivity and specificity are 87% and 91%, respectively, for cirrhosis and 70% and 84%, respectively, for F2 or higher disease.10 In a study of 97 Japanese patients with NAFLD, transient elastography had good overall accuracy, with AUROCs of 0.87, 0.90, and 0.99 for F2 or greater, F3 or greater, 上海皓元 and F4 diseases, respectively.20 Similar levels of accuracy and reproducibility were observed in 50 pediatric NAFLD patients in Italy.25 However, in this study, only 10 patients had F3 or higher fibrosis. Our study confirms that transient elastography works well in both white and Asian NAFLD patients. At cutoff values of 8.7 and 10.3 kPa, the negative predictive values to exclude F3 or greater disease and cirrhosis were 95% and 99%, respectively. The adoption of transient elastography could potentially spare two thirds of NAFLD patients from liver biopsies. Because the prevalence of NAFLD is high in many affluent countries, this approach would be cost saving.