Background:  Transient elastography is a novel, non-invasive technique to evaluate liver stiffness. No data are reported in patients with HIV/hepatitis B virus (HBV) co-infection, and the cut-off distinguishing fibrosis stages is possibly different from that observed in hepatitis C virus (HCV) -mono- or -co-infected patients. 

Methods:  We prospectively assessed the performance of FibroScan in HIV/HBV-co-infected patients in comparison with liver biopsy as reference and performed within a short time frame. Our study was conducted from September 2005 to September 2006 in 31 consecutive HIV/HBV-co-infected patients. All patients had a liver biopsy except 1 with a previous histologically proven cirrhosis. Quality of FibroScan was assessed by a rate of success ≥60% and an interquartile range (IQR) ≤30% of median elasticity for patients with body mass index <28. For patients with body mass index >28, we accepted a lower rate of success (≥30%) with the same level of IQR.

Results:  Of 31 patients, 24 (77%) were male; median age was 43 years (range 25 to 64) and median body mass index was 22 kg/m² (17 to 32); median duration of HIV and HBV infection was 11.5 and 9.1 years, respectively. At the time of liver biopsy, the majority of patients were under HAART (94%), including a molecule active against HBV in 28 of 29 patients:  lamivudine (3TC) in 7, tenofovir (TDF) in 3, and both in 18 cases. Median time between liver biopsy and FibroScan was 4.5 days (0 to 195). Liver biopsy and FibroScan were performed on the same day for 7 patients, and within 1 month for 19 cases. Median length of liver biopsy was 18 mm. The METAVIR fibrosis stage was F0F1 for 11, F2 for 10, and F3F4 for 10 patients, respectively. FibroScan values ranged from 3 to 21 kPa (median 7 kPa). For patients with F0F1, F2, F3F4 fibrosis score, median liver stiffness measurements were 5.40, 6.80, and 8.35 kPa, respectively. A significant correlation was observed between liver stiffness measurements and METAVIR fibrosis stage (τ-B = 0.42; p = 0.002). ROC curves analyses were conducted to distinguish F0F1 from F2F3F4 and F0F1F2 from F3F4. AUC were 0.79 (IC95%, 0.63 to 0.95, p = 0.009) and 0.73 (IC95%, 0.54 to 0.93, p = 0.038), respectively. Thresholds for the best sensitivity and specificity were 6.5 kPa for distinguishing patients with fibrosis ≥F2, and 7.35 kPa for those ≥F3.

Conclusions:  Our study confirms the relevance of FibroScan to evaluate fibrosis in HIV/HBV-co-infected patients. Since the number of patients was still limited, the exact cut-off value should be further refined in HIV/HBV co-infection.