Performance of unidimensional transient elastography in staging chronic hepatitis C. Results from a cohort of 1,202 biopsied patients from one single center.
The current study aimed to establish the liver stiffness (LS) cut-off values and their performance in the prediction of the fibrosis stage in chronic hepatitis C (CHC) patients, to find the anthropometric and biochemical factors leading to overestimation of the fibrosis stage and to analyze the factors leading to the technique failure. 1,202 consecutive CHC patients were prospectively included in the study. All of them underwent percutaneous liver biopsy for grading and staging the disease (METAVIR) and were referred to LS measurement 1 day prior to biopsy. LS values varied between 2.8-75 kPa. Transient elastography success rate (SR) ranged between 0-100% (84.82 +/- 24.46%). In 27 patients (2.2%), no valid measurement was obtained; high BMI influenced independently the measurement failure. In 11.2% of cases, the SR was <60%, but 10 valid measurements were nevertheless recorded; the female sex and high BMI were the only factors independently leading to a SR<60%. AUROCs for the diagnosis of fibrosis F≥1, F≥2, F≥3, and F=4 were 0.879, 0.889, 0.941 and 0.970, for the cut-off values of 5.3 kPa, 7.4 kPa, 9.1 kPa and 13.2 kPa respectively, and they did not significantly differ from the adjusted AUROC values. The patients with false positive results were younger and had significantly higher serum aminotransferase (ALT, AST) and gamma glutamyl-transpeptidase levels than the patients with concordant results. The multivariate analysis showed that only high ALT levels influenced independently the occurrence of false positive results. Transient elastography is a useful non-invasive method for the assessment of fibrosis in CHC patients. However, it must be interpreted in the clinical and biochemical context, in order to insure high-quality results.