Tenofovir plasma concentrations related to estimated glomerular filtration rate changes in first-line regimens in African HIV-infected patients: ANRS 12115 DAYANA substudy

OBJECTIVES: An open-label randomized trial (DAYANA) was conducted in sub-Saharan settings to evaluate four different regimens containing tenofovirdisoproxil fumarate as first-line treatment for HIV infection. The objectives of the present substudy were to assess the relationship between trough concentrations of tenofovirin plasma collected after 24 h (C24) and estimated glomerular filtration rates (eGFR) calculated by the different formulae that are available. METHODS: The criteria for eligibility were those of the DAYANA trial, recruiting naive patients. The four tenofovirregimens were: Group 1, tenofovir/ emtricitabine/ nevirapine; Group 2, tenofovir/ lopinavir/ritonavir; Group 3, tenofovir/ emtricitabine/ zidovudine; and Group 4, tenofovir/ emtricitabine/ efavirenz. The C24 of tenofovirwas determined using LC-MS/MS. The eGFR was calculated using the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulae. RESULTS: The median C24 of tenofovirwas 42 ng/mL. The C24 of tenofovirwas higher with lopinavir/ritonavirthan with the other three regimens: at Week 4, 84 ng/mL versus 25 ng/mL; and at Week 48, 81 ng/mL versus 52 ng/mL. The baseline merged eGFR was 98.2 mL/min/1.73 m(2) with the CKD-EPI equation. Only the mean changes in eGFR in Group 2 differed from the absolute value of zero (-8.2 mL/min/1.73 m(2)) with the CKD-EPI equation between baseline and Week 48. The Cockcroft-Gault formulais inappropriate for these African patients because it underestimated the baseline eGFR and overestimated the changes in eGFR between baseline and Week 48. CONCLUSIONS: In this population of mostly female HIV-1-infected African patients, tenofovirplasma overexposure was associated with PI/ ritonavirand a time-dependent decrease in eGFR, probably via an inhibition of MRP2/MRP4 efflux transporters. The close monitoring over time of the eGFR using MDRD or CKD-EPI calculations and by using other biomarkers of renal disorder should be proposed as an alternative to therapeutic drug monitoringin resource-limited countries.