MO177RENAL PROXIMAL TUBULAR DISORDER AND RENAL FUNCTION LOSS IN HIV-INFECTED PATIENTS TREATED WITH TENOFOVIR DISOPROXIL FUMARATE

Abstract

Abstract Background and Aims Tenofovir disoproxil fumarate (TDF), as the most common antiviral drug, can cause both proximal tubular transportation dysfunctions and eGFR decline. The relationship between them is not clear due to lack of clinical data from large cohorts, especially in the Chinese population. In this study, we summarized the characteristics of proximal tubular injuries and eGFR decline in the cohort of HIV-infected patients treated with TDF, and explore the the impact of tenofovir on tubular transporters in vitro. Method We enrolled HIV-infected patients treated with TDF, who were regularly followed up in our hospital from Sep 1, 2001 to August 31, 2019. Their baseline and follow-up clinical data were collected. Proximal tubular dysfunction was defined as meeting two or more of the following criteria: hypophosphatemia, hypouricemia, low carbon dioxide binding capacity, positive urine glucose with normal plasma glucose level, and positive urine protein. Rapid deterioration of renal function was defined as the annual decline rate of eGFR exceeding 5ml/min/1.73m2. We also used human renal proximal tubular epithelial cell line (HK2) to further investigate the impact of tenofovir on transporters including SGLT2, NaPi-IIa, and URAT1 through immunofluorescence. Results A total of 375 HIV-infected patients receiving TDF were enrolled, mainly males (90.1%), with a median follow-up duration of 34(17, 58) months. The most common clinical manifestations were proteinuria (20.3%) and hypophosphatemia (12.3%). The prevalence of proximal tubular injury was 6.7%, which was significantly associated with low body weight, but was not associated with age, TDF course, baseline viral load, or baseline CD4+ T lymphocyte count. Their eGFR levels at the end of the follow-up were significantly lower than the baseline levels (104.6±15.2 vs. 110.6±14.2 ml/min/1.73m2, P<0.001). The average annual decline rate of eGFR was 5.0± 22.7 ml/min/1.73m2, and 23.6% of our patients had an annual decline rate of eGFR exceeding 5 ml/min/1.73m2. Rapid deterioration of renal function (≥ 5 ml/min/1.73m2 per year) was significantly associated with female but not related to proximal tubular dysfunction in multivariate logistic regression analysis. In vitro, the survival rate of HK2 cells was more than 95% when treated with tenofovir with a concentration of 1μmol/L for 48h. The expression levels of transporters (SGLT2, URAT1, and NaPi-IIa) were declined under the condition. Conclusion Among the HIV-infected Chinese patients treated with TDF, 6.7% had proximal tubular dysfunction and 23.6% showed accelerated annual decline rate of eGFR (≥ 5 ml/min/1.73m2 per year).