Renal function and lipid metabolism in Japanese HIV-1-positive individuals 288 weeks after switching from tenofovir disoproxil fumarate to tenofovir alafenamide fumarate: a single-center, retrospective cohort study

Background Continued use of tenofovir disoproxil fumarate (TDF), an antiretroviral drug, causes renal function decline and tubular damage in individuals with HIV. While tenofovir alafenamide fumarate (TAF) may have less damaging effects, it causes weight gain and abnormal lipid metabolism. Methods This single-center, retrospective cohort study used medical records from the National Hospital Organization Sendai Medical Center to investigate renal function of Japanese HIV-1-positive individuals who switched from TDF to antiretroviral therapy including TAF by 2017. The endpoints were: estimated glomerular filtration rate (eGFR), urinary β2 microglobulin (Uβ2MG), weight, and lipid metabolism parameters at 288 weeks after switching. Possible correlation between eGFR and Uβ2MG and factors affecting eGFR decline were examined. Results Sixty patients switched from TDF to TAF and continued therapy for 288 weeks. eGFR showed a significant decline after 144 weeks, although it was controlled from the time of change until 96 weeks. In the renal impairment group, the decline was suppressed until week 288. Uβ2MG continued to decrease significantly after 48 weeks. However, the suggested correlation between eGFR and Uβ2MG disappeared when patients switched from TDF to TAF. Weight and lipid metabolic parameters increased significantly at 48 weeks and were maintained. Factors associated with decreased eGFR were: history of acquired immune deficiency syndrome (AIDS) and Uβ2MG. However, considering the odds ratio, the switch from TDF to TAF suppressed the eGFR decline in the group with a history of AIDS, and Uβ2MG had no effect on the eGFR decline. Conclusions Switching from TDF to TAF for the long term slows eGFR decline, decreases Uβ2MG levels, and reduces worsening of renal function. Weight gain and abnormal lipid metabolism may occur in the short term but are controllable.