Recovery of eGFR in patients who develop renal complications on tenofovir

Abstract

PurposeTenofovir (TDF) use has been linked to chronic kidney disease (CKD) and rapid decline in kidney function; the potential reversibility of these complications remains poorly studied. We compared changes in estimated glomerular filtration rate (eGFR) before, during and after TDF use.MethodsPatients in the UK Collaborative HIV Cohort (CHIC) Study who discontinued a TDF‐containing regimen after>3 months were included. Incident CKD on TDF was defined as an eGFR<60 for>3 months (eGFR units=ml/min/1.73 m2) and rapid eGFR decline as a negative eGFR slope>3 on TDF (eGFR slopes measured in ml/min/1.73 m2/year). Linear piecewise regression was used to estimate each person's eGFR slope before, during and after TDF, excluding the initial 4 weeks on TDF and the first 3 months post‐entry and post‐discontinuation. These slopes were compared in those with/without CKD or rapid eGFR decline using t‐tests. A piecewise linear random effects model compared the average slopes before and during TDF, and during and post TDF. Maximum eGFR after discontinuation was compared with eGFR at TDF start to determine the extent of recovery.Results935 subjects were included, of whom 80% were male, 70.5% of white ethnicity, 66.2% MSM. Median age at TDF start was 41. Patients with incident CKD tended to have lower eGFR at TDF start than those without (median 75 and 93 respectively), while baseline eGFR in those with/without rapid eGFR decline were similar (median 90 and 91 respectively). Small eGFR declines pre‐TDF were observed in all patients, with significantly more rapid eGFR decline observed during TDF exposure in those with renal complications (Table). Table. eGFR slopes before, during and after TDF exposure in those with and without renal complications eGFR slope Pre‐TDF On‐TDF Post‐TDF Pre‐TDF vs. on‐TDF On‐TDF vs. post‐TDF CKD −2.7 −7.3 +5.2 p<0.0001 p<0.0001 No CKD −1.1 −4.4 +2.6 p<0.0001 p<0.0001 p=0.10 p=0.003 0.001 Rapid eGFR decline −0.5 −10.1 +5.1 p<0.0001 p<0.0001 No rapid eGFR decline −1.8 +0.2 +1.1 p=0.28 p<0.0001 p=0.07 p<0.0001 p<0.0001 Although eGFR recovery was observed in the majority of patients without renal complications following TDF discontinuation (70.5% of those without CKD, 76.3% of those without rapid eGFR decline), only 43.7% of patients with CKD and 56.4% of those with rapid eGFR decline reached a maximum eGFR that was at least as high as their eGFR at TDF start.ConclusionsImprovements in eGFR were observed in patients who discontinued TDF. However, incomplete eGFR recovery was frequent in those with renal complications.