CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

Results: TFV incubation of OAT1-HEK-293 cells resulted in increased autophgic flux (99.4 ± 5.8% change to control; P<0.001), lysosomal hyper-activation, increased lysosomal mass (74.2 ± 7.0% change to control; P<0.001) and acidity (31.5 ± 1.3% change to control; P<0.001) and higher activity of the lysosomal cell death executors cathepsin B and L (75.7 ± 5.2% and 76.2 ± 3.6% change to control; P<0.001). These changes were associated with decreased membrane stability, decreased relative abundance of lysosomal stabilizing proteins LAMP1 and 2 (-33.2 ± 2.7% and -45.7 ± 2.2 change to control; P<0.05, P<0.001) loss of lysosomal integrity (Control 20.6 ± 1.2% vs TFV 43.2 ± 2.2%; P<0.001) and compromised cell viability and were related to intracellular TFV amount. Importantly, inhibition of lysosomal activity using ammonium chloride (NH4Cl) or chloroquine (CQ) counteracted cell toxicity and rescued cell viability (Cell death without NH4Cl/CQ 180.2 ± 23.2% change to control vs plus NH4Cl -16.5 ± 6.9 % or plus CQ -55.4 ± 3.7%; P<0.001). Conclusion: Intracellular accumulation of TFV induces lysosomal toxicity as demonstrated by organelle hyper-activation and membrane destabilization ultimately leading to compromised kidney cell viability. Our results contribute to a better understanding of the long-term side effects of this commonly used antiviral agent. 692 DYNAMICS OF E-FGR WITH ONE OR MORE ANTIRETROVIRALS THAT INHIBIT CR TUBULAR SECRETION Maria Jesus P. Elias 1 , M.Mar Gutierrez 2 , Manuel Crespo 3 , Ignacio Santos 4 , Esteban Ribera 5 , Maria J. Galindo 6 , Fernando Lozano 7 , Antonio Payeras Cifre 8 , Vicente Boix 9 , Marta Montero 10 , José Sanz 11 , Javier De La Torre Lima 12 , Jesus Santos 13 , Sara de la Fuente Moral 14 , Esteban Martinez 2 1 Hospital Ramón y Cajal, Madrid, Spain, 2 Universitat de Barcelona, Barcelona, Spain, 3 Hospital Universitario Alvaro Cunqueiro, Vigo, Spain, 4 Hospital Universitario de La Princesa, Madrid, Spain, 5 Vall d’Hebron Research Institute, Barcelona, Spain, 6 Hospital Clinic of Valencia, Valencia, Spain, 7 Hospital Universitario de Valme, Seville, Spain, 8 Hospital Son Llàtzer, Palma de Mallorca, Spain, 9 Hospital General Universitario de Alicante, Alicante, Spain, 10 Hospital Universitario y Politecnico La Fe, Valencia, Spain, 11 Hospital Universitario de Guadalajara, Guadalajara, Spain, 12 Mayo Clinic, Rochester, MN, USA, 13 Hospital Virgen de la Victoria, Málaga, Spain, 14 Clinica Puerta de Hierro, Madrid, Spain Background: Cobicistat (C), dolutegravir (DLT) and rilpivirine (RPV) all are modest antiretroviral drugs that inhibit proximal tubular creatinine secretion and hence a moderate and early non progressive creatinine estimated glomerular filtration (Cr-eGFR) reduction has been observed in clinical trials. Neither in vitro, nor clinical trials have explored whether combination of these drugs may have an additive effect in the inhibition of creatinine secretion. Methods: Cr-eGFR changes after starting Darunavir (DRV)/c alone or in combination with DTG and/or RPV were assessed in a nation-wide retrospective cohort study of consecutive HIV-infected patients initiating DRV/c from June/2014 to March/2017. The eGFR was calculated with Cr-CKD-EPI in mL/ min/1.73m2. The relationship between Cr-eGFR change over time and the use of DRV/c alone or in combination with DTG and/or RPV adjusted by different factors that might influence Cr-eGFR such as HIV patient´s characteristics, socio- demographics, HIV severity, use of TDF, and concomitant medication other than ARV was explored. Ethics approval was obtained and patients signed informed consent. Results: There were 761 patients (85%men, 91% Caucasian, 99% antiretroviral-experienced, 34% HCV coinfected, 80% on prior DRV/ritonavir, 32% prior AIDS, 84% HIV RNA < 50 copies/mL, 88%≥200 CD4/mm3) from 21 Spanish HIV Units. Thirty-six (5%) patients were excluded due to the lack of Cr-eGFR data. Mean baseline (SD) Cr-eGFR was 94 (19) and 5% had eFGR below 60, increasing to 8% at 48 week. Only 6 (1%) patients had DRV/c switched DRV/c due to renal adverse effects. Higher significant decreases in Cr-eGFR were observed in patients taking two or more Inhibitors of Tubular Cr Secretion at week 24, and a strong trend at week 48 (Figure). In multivariate analysis in patients receiving DRV/c, female sex was associated with a significant improvement of Cr-eGFR adjusted median difference (AMD) 2.5±1.3 CI 95% (0.4; 5.1) P=0.047, while the combination of DRV/c with either RPV or DTG or both decreases Cr-eFGR AMD 3.5±1.6 CI 95% (-6.6 ; -0.3); p= 0.032. Conclusion: The concomitant use of Darunavir/cobicistat plus other known inhibitors of tubular creatinine secretion (dolutegravir, Rilpivirine or both) produced an additive effect in the expected Cr-eGFR decrease.

CKD-associated SNPs significantly contributed to CKD in uni- and multivariable analysis (Figure). In the final multivariable model, participants in the 3rd and 4th genetic score quartiles had a CKD OR of 1.62 (95% confidence interval, 1.23–2.21) and 2.01 (1.47–2.81), compared to the 1st quartile (most favorable genetic background). In comparison, persons in the 3rd and 4th quartile of the D:A:D CKD risk score had CKD OR of 1.47 (1.09–1.98) and 1.88 (1.32–2.57), compared to the most favorable 1st quartile. Cumulative exposure per 5 years to atazanavir/ritonavir, lopinavir/ritonavir, and tenofovir disoproxil fumarate were associated with CKD OR of 2.96 (2.03–4.74), 1.69 (1.27–2.26), and 1.81 (1.43–2.36), respectively. Conclusion: The effect of an unfavorable genetic background on CKD risk in HIV-positive persons was similar to the effect of the established D:A:D clinical risk score, and similar to 5-year exposure to nephrotoxic antiretrovirals. Genetic testing may provide prognostic CKD information complementary to clinical and antiretroviral risk factors.

Poster Abstracts

691 LYSOSOMAL TOXICITY AS A NOVEL MECHANISM IN TENOFOVIR- ASSOCIATED NEPHROTOXICITY

Metodi Stankov 1 , Ruisi Lin 1 , Ramachandramouli Budida 1 , Diana Panayotova- Dimitrova 2 , Reinhold E. Schmidt 1 , Georg Behrens 1 1 Medizinische Hochschule Hannover, Hannover, Germany, 2 RWTH Aachen University Hospital, Aachen, Germany Background: Tenofovir disoproxil fumarate (TDF) treatment can lead to renal impairment. Experimental data suggest that tenofovir (TFV)-mediated mitochondrial toxicity contributes to tubular cell damage. We hypothesized that tenofovir induces lysosomal hyper-activation and destabilization, which compromises renal proximal tubular function and viability. Methods: The aim of the study was to assess the effects of TFV and TDF on autophago-lysosomal homeostasis, autophagic flux, lysosomal mass, lysosomal membrane composition, acidity, cathepsin activity and kidney cell viability in organic anion transporter 1 (OAT1) expressing (OAT1-HEK-293) and parental WT-HEK-293 kidney cells. Analyses were performed using immunostaining, calorimetric measurements, flow cytometry, real-Time PCR and confocal microscopy.

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