Assessment of liver fibrosis in trnsplant recipients with recurrent HCV infection: Usefulness of transient elastography

BACKGROUND: Progression of recurrent hepatitis C is accelerated in liver transplant recipients, leading to special need of non-invasive validated methods to estimate liver fibrosis. AIM: To assess the efficacy of liver stiffness measurement by transient elastography (Fibroscan) and serum parameters in predicting fibrosis stage in HCV-infected transplant recipients. METHODS: The correlation between liver fibrosis, assessed at liver histology on bioptic specimens obtained for clinical indications, and stiffness or clinico-serological indexes (Benlloch, APRI, Forns, Fibrotest and Doppler resistance index), was investigated in transplant recipients with recurrence of HCV chronic hepatitis. A total of 56 patients (of which 36 with all clinico-serological indexes), presenting with the following METAVIR fibrosis stage F1=38, F2=9, F3=8, F4=1, were enrolled in the study population. Differences between fibrosis stages were calculated by non-parametric analysis. The best cut-off for identifying significant fibrosis (F2-F4) was assessed by ROC curve analysis. RESULTS: Stiffness (median and range) was 7.7 KPa (range 4.2-13.9) in F1 and 17.0KPa (range 6.8-36.3) in >or=F2 (p<0.001). A stiffness cut-off of 10.1 KPa revealed 94% Sensitivity, 89% Specificity, 81% PPV and 94% NPV in differentiating F1 from F2-F4. The area under the receiver operator curve in the assessment of fibrosis was significantly higher for Liver stiffness (AUROC 0.943) than for any of the other non-invasive indexes (AUROCs ranging 0.591-0.815). CONCLUSIONS: Transient elastography of the liver provides good accuracy in identifying patients with significant fibrosis and performs better than non-invasive indexes based on clinico-serological parameters in transplant recipients.