Validation of the FibroTest Biochemical Markers Score in assessing liver fibrosis in hepatitis C patients
Rossi, E., Adams, L., Prins, A., Bulsara, M., de Boer, B., Garas, G., et al. (2003). Validation of the fibro test biochemical markers score in assessing liver fibrosis in hepatitis C patients. Clinical Chemistry, 49(3), 450-454. doi: 10.1373/49.3.450
Background: Determining the stage of fibrosis by liver biopsy is important in managing patients with hepatitis C virus infection. We investigated the predictive value of the proprietary FibroTest score to accurately identify significant fibrosis in Australian hepatitis C patients.
Methods: Serum obtained from 125 confirmed hepatitis C patients before antiviral therapy was analyzed for haptoglobin, α2-macroglobulin, apolipoprotein A1, bilirubin, and γ-glutamyltransferase activity, and the FibroTest score was computed. Liver fibrosis pathology was staged according to a defined system on a scale of F0 to F4. We used predictive values and a ROC curve to assess the accuracy of FibroTest scores.
Results: The prevalence of significant fibrosis defined by liver biopsy was 0.38. The most useful single test for predicting significant fibrosis was serum 2-macroglobulin (cutoff value, 2.52 g/L; sensitivity, 75%; specificity, 67%). The negative predictive value of a FibroTest score <0.1 was 85%, and the positive predictive value of a score >0.6 was 78%. Although 33 of the 125 patients had FibroTest scores <0.1 and were therefore deemed unlikely to have fibrosis, 6 (18%) had significant fibrosis. Conversely, of the 24 patients with scores >0.6 who were likely to have significant fibrosis, 5 (21%) had mild fibrosis. Of the 125 patients in the cohort, 57 (46%) could have avoided liver biopsy, but discrepant results were recorded in 11 of those 57 (19%).
Conclusion: The FibroTest score could not accurately predict the presence or absence of significant liver fibrosis.