Diagnostic value of serum protein profiling by SELDI-TOF - ProteinChip compared with a biochemical marker, FibroTest, for the diagnosis of advanced fibrosis in patients with chronic hepatitis C

Background FibroTest has been validated for the diagnosis of liver fibrosis in patients with chronic hepatitis C. Aim To compare FibroTest with a new proteome-based model for the prediction of advanced liver fibrosis. Methods Sera from 191 consecutive patients with simultaneous liver biopsy and FibroTest on fresh sera were used for retrospective mass spectrometry analysis. A new fibrosis index was constructed combining proteomic peaks, selected on differential expression according to fibrosis stages in logistic regression analyses. The main end point was the diagnosis of advanced fibrosis on liver biopsy. Results Eight out of 1000 peaks were selected for the construction of the proteomic index. The area under the receiver operating curve (AUROC) of the proteomic index was 0.88 (95% CI: 0.82-0.92), significantly greater than the FibroTest AUROC of 0.81 (95% CI: 0.74-0.86; P = 0.04); the AUROC of the proteomic and FibroTest combination was 0.88 (95% CI: 0.83-0.92). Seven of the eight selected peaks were highly associated with the FibroTest score, with different patterns of association with the five components of FibroTest. Conclusions A proteomic index combining eight peaks had an excellent accuracy value for the diagnosis of advanced fibrosis in patients with chronic hepatitis C. However, despite a statistical significance, the small improvement delivered by proteomics impairs clinical applications because of its cost and its variability compared with the well validated FibroTest.