Comparison of blood tests for liver fibrosis specific or not to NAFLD

Background/Aims: To compare blood tests of liver fibrosis specific for NAFLD: the FibroMeter NAFLD and the NAFLD fibrosis score (NFSA) with a non-specific test, APRI. Methods: Two hundred and thirty-five NAFLD patients with liver Metavir staging and blood markers from two independent centres were randomly assigned to a test (n = 121) or a validation population (n = 114). Results: The highest accuracy - 91% - for significant fibrosis was obtained with the FibroMeter whose (i) AUROC (0.943) was significantly higher than those of NFSA (0.884, p = 0.008) and APRI (0.866, p < 10-3; p = 0.309 vs NFSA) in the whole population, and (ii) misclassification rate (9%) was significantly lower than those of NFSA (14%, p = 0.04) and APRI (16%, p = 0.002) and did not vary according to centre (14 vs 7%, p = 0.07), unlike those of NFSA (25 vs 9%, p = 0.001) and APRI (29 vs 11%, p < 10-3). By using thresholds of 90% predictive values, liver biopsy could have been avoided in most patients: FibroMeter: 97.4% vs NFSA: 86.8% (p < 10-3) and APRI: 80.0% (p < 10-3). A new classification provided three reliable diagnosis intervals: F0/1, F0/1/2, F2/3/4 with 91.4% accuracy for FibroMeter, avoiding biopsy in all patients. Conclusions: FibroMeter NAFLD had high performance and provided reliable diagnosis for significant fibrosis, significantly outperforming NFSA and APRI. © 2008 European Association for the Study of the Liver.