TAF for HIV-HBV With Renal Dysfunction

Rationale: Tenofovir alafenamide (TAF) has been shown to cause less renal complications than tenofovir disoproxil fumarate (TDF) while having the same virological efficacy against HIV and HBV infections. In a recent study from the USA and Japan, over 90% of HIV/HBV-coinfected individuals had a suppressed HBV viral load 48 weeks after TDF was replaced by TAF. Thus, TAF might be a valuable treatment option for HIV/HBV-coinfected individuals with TDF-toxicity, especially in the context of resistance to lamivudine and entecavir. However, the safety and efficacy of TAF has not been evaluated to date in HIV/HBV-coinfected patients with renal dysfunction. Primary objectives: * To evaluate changes in glomerular and tubular renal function after switch from TDF to TAF in HIV/HBV coinfected patients with renal dysfunction * To assess the HBV virological efficacy of TAF in HIV/HBV coinfected patients with renal dysfunction switching from TDF to TAF. Secondary objectives: * To assess the percentage of and reasons for treatment interruptions * To describe toxicity events including liver-related complications * To evaluate changes in liver fibrosis Intervention: In eligible patients willing to participate and who have signed an informed consent TDF will be replaced by TAF on day 1 of the study. Products: * Tenofovir alafenamide/emtricitabine (TAF/FTC) Dose: one tbl. once per day in addition to at least one third compound OR * Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (EVG/COBI/FTC/TAF) Dose: one tbl. once per day Study Population: eligible patients from all 7 centers of the Swiss HIV Cohort Study will be considered.