Improved kidney function in patients who switch their protease inhibitor from atazanavir or lopinavir to darunavir.

OBJECTIVE: Atazanavir (ATV) and lopinavir (LPV) have been associated with kidney disease progression in HIV positive patients, with no data reported for darunavir (DRV). We examined kidney function in patients who switched their protease inhibitor from ATV or LPV to DRV. DESIGN: Cohort study. METHODS: Data were from the UK CHIC study. We compared pre and post switch estimated glomerular filtration rate (eGFR) slopes (expressed in ml/min per 1.73 m per year) in all switchers and those with rapid eGFR decline (>5 ml/min per 1.73 m per year) on ATV or LPV. Mixed-effects models were adjusted for age, gender, ethnicity, eGFR at switch and time updated CD4 cell count, HIV RNA and cumulative tenofovir (tenofovir disoproxil fumarate) exposure. RESULTS: Data from 1430 patients were included. At the time of switching to DRV, median age was 45 years, 79% were men, 76% had an undetectable viral load, and median eGFR was 93 ml/min per 1.73 m. Adjusted mean (95% confidence interval) pre and post switch eGFR slopes were -0.84 (-1.31, -0.36) and 1.23 (0.80, 1.66) for ATV (P < 0.001), and -0.57 (-1.09, -0.05) and 0.62 (0.28, 0.96) for LPV (P < 0.001). Stable or improved renal function was observed in patients with rapid eGFR decline on ATV or LPV who switched to DRV [-15.27 (-19.35, -11.19) and 3.72 (1.78, 5.66), P < 0.001 for ATV, -11.93 (-14.60, -9.26) and 0.87 (-0.54, 2.27), P < 0.001 for LPV]. Similar results were obtained if participants who discontinued tenofovir disoproxil fumarate at the time of switch were excluded. CONCLUSIONS: We report improved kidney function in patients who switched from ATV or LPV to DRV, suggesting that DRV may have a more favourable renal safety profile.

Renal tubular disease in the era of combination antiretroviral therapy.

OBJECTIVES: To describe the spectrum of renal tubular disease (RTD) in HIV-positive patients and its association with exposure to antiretroviral therapy (ART). DESIGN: Review of 265 consecutive renal biopsies from HIV-positive patients attending eight clinics in the United Kingdom between 2000 and 2012. METHODS: We described the clinical characteristics of patients with RTD and compared current/recent exposure (at the time of, or up to 3 months prior to the date of biopsy) to potentially nephrotoxic ART [tenofovir (TDF), atazanavir (ATV), indinavir (IDV) and lopinavir/ritonavir (LPV/r)]. We also analysed the incidence of RTD in the UK CHIC cohort. Kruskall-Wallis, analysis of variance and Fisher's exact tests were used to evaluate between-group differences. RESULTS: Of the 60 RTD cases, 54 (90%) were included in the analyses. RTD comprised of three distinct patterns: acute tubular injury (ATI, n = 22), tubulo-interstitial nephritis (TIN, n = 20) and interstitial fibrosis and tubular atrophy (IFTA, n = 12). Compared with TIN and IFTA, ATI cases were less likely to be of black ethnicity (10 vs. 42-55%; P = 0.006), more likely to be on ART (100 vs. 55-68%; P = 0.001), with HIV-RNA below 200 copies/ml (100 vs. 54-58%; P < 0.001), and more likely to have current/recent exposure to TDF (P < 0.001). We did not find evidence for an association between exposure to TDF, ATV/r or LPV/r and either TIN or IFTA. CONCLUSION: RTD was present in approximately 20% of renal biopsies and comprised three distinct injury patterns with considerable clinical overlap. ATI was associated with TDF exposure, although the overall incidence of biopsy-defined ATI was low.