Abstract

TUPE254 - Poster Exhibition

Progression to impaired estimated glomerular filtration rate (eGFR) between antiretroviral therapy regimens in the Canadian Observational Cohort (CANOC) collaboration

S.R. Hosein^1,2, K. Johns³, K. Chan⁴, J. Raboud^5,6, M. Harris^3,4, D. Milan⁴, G. Bondy⁷, A.M. Cescon⁴, C. Cooper⁸, M.B. Klein^9,10, M.R. Loutfy^11,12,13, N. Machouf¹⁴, J.S. Montaner^3,4, C. Tsoukas¹⁰, R.S. Hogg^4,15, A. Rachlis¹⁶, CANOC Collaboration

¹CATIE, Toronto, Canada, ²Canadian Observational Cohort (CANOC) collaboration, Vancouver, Canada, ³University of British Columbia, Faculty of Medicine, Vancouver, Canada, ⁴BC Centre for Excellence in HIV/AIDS, Vancouver, Canada, ⁵University Health Network, Division of Infectious Diseases, Toronto, Canada, ⁶University of Toronto, Dalla Lana School of Public Health, Toronto, Canada, ⁷University of British Columbia, Department of Medicine and Pathology, Vancouver, Canada, ⁸University of Ottawa, The Ottawa Hospital Division of Infectious Diseases, Ottawa, Canada, ⁹McGill University Health Centre, The Montreal Chest Institute, Montreal, Canada, ¹⁰McGill University, Faculty of Medicine, Montreal, Canada, ¹¹Women's College Hospital, Women's College Research Institute, Toronto, Canada, ¹²Maple Leaf Medical Clinic, Toronto, Canada, ¹³University of Toronto, Faculty of Medicine, Toronto, Canada, ¹⁴Clinique Medicale l'Actuel, Montreal, Canada, ¹⁵Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada, ¹⁶University of Toronto, Department of Medicine, Division of Infectious Diseases, Toronto, Canada

Background: Although potent antiretroviral therapy (ART) can significantly extend survival, concerns remain about long-term safety. Renal safety is an emerging issue in the treatment of chronic HIV infection and eGFR is an important clinical tool for assessing renal function. This study investigates whether use of atazanavir or lopinavir correlates to progression to impaired eGFR among patients on NRTI backbone containing either tenofovir (TDF) or abacavir (ABC).
Methods: Treatment-naïve HIV-1-infected participants with initial ART regimens containing TDF or ABC were prospectively followed since 2000 across Canada. Regular assessments of viral load, CD4+ cell count, co-infections, creatinine, and lipid parameters were conducted. MDRD equations were used to calculate eGFR. Cox regression analysis was used for time to impaired eGFR (defined as < 60 mL/min).
Results: A total of 965 patients were included in this analysis (87% male, 13% female), median age 39 years (IQR 33-45), 14% known IDU, 18% hepatitis C positive, median CD4 219 cells/mm3 (IQR 137-290), median VL 4.8 log10 copies/ml (IQR 4.3-5.0). Baseline NRTI use included 283 on ABC and 682 on TDF; initial third agents included 384 on atazanavir, 192 on lopinavir, and 389 on non-PI. In a multivariable proportional hazards model adjusting for province, baseline CD4, baseline VL, age, year therapy started, baseline eGFR and rate of eGFR testing, TDF use was not associated with increase risk of impaired eGFR (aHR 1.16, 95% CI 0.94-1.43, p=.177) compared to ABC use. Both lopinavir (aHR 1.32, 95% CI 1.04-1.69, p=.024) and atazanavir (aHR 1.46, 95% CI 1.18-1.81, p< .001) were associated with impaired eGFR relative to non-PI use.
Conclusion: Results from this cohort suggest that treatment-naïve HIV-positive patients who are given PI-based regimens, particularly atazanavir, appear to be at increased risk for mild-to-moderate renal toxicity. We plan further analyses to explore this finding.
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