RESUMEN
Background & aims: Tenofovir alafenamide fumarate (TAF) was shown equally efficacious in suppressing hepatitis B virus (HBV) but with less renal toxicity than tenofovir disoproxil fumarate (TDF). The aim of this real-world study was to evaluate renal function in post-liver transplantation (LT) patients that changed TDF with TAF. Methods: The TAF group (n=17) included patients who switched to TAF due to low (<60 ml/min/1.73m2) Glomerular Filtration Rate (GFR). The control group included patients that remained on TDF (n=30), although some (n= 14) had chronic kidney disease (CKD) (TDF-CKD group). GFR was assessed using: i) MDRD-6 variable; ii) CKD-EPI formula; iii) radionuclide technique (rGFR). Results: There were no significant differences between the two groups except for the presence of diabetes and follow-up period, which were more common and shorter, respectively, in the TAF group (35% vs. 10%, p=0.03; 13.7 vs. 35.5 months, p<0.001). At the end of follow-up there were no significant changes in renal function between the TAF and the TDF group or TDF-CKD group, although the numerical change in rGFR in the latter comparison was greater in the TAF group (ΔrGFR 3 vs. -2.14 ml/min, p=0.26). The use of everolimus was associated with improvement in renal function (ΔrGFR 2 vs. -7.75 ml/min, p=0.06 [TAF vs. TDF group]; 2 vs. -12 ml/min, p=0.01 [TAF vs. TDF-CKD group]). There were no TAF- related side effects or cases of HBV recurrence. Conclusion: Conversion to TAF in post-LT patients who develop CKD does not lead to improvement of kidney function after a period of one year.