Effects of long-term exposure to tenofovir disoproxil fumarate-containing antiretroviral therapy on renal function in HIV-positive Chinese patients

Evaluation of Pharmacokinetics of a BCS Class III Drug with Two Different Study Designs: Tenofovir Alafenamide Monofumarate Film-coated Tablet

Tenofovir alafenamide (TAF) is a BCS Class III compound and an oral pro-drug of Tenofovir (TFV) with limited oral bioavailability. The bioavailability of the oral intake increases with food as a result of the low stability of the active substance in the stomach. The reference drug is "Vemlidy® 25 mg Film Tablet", which contains 25 mg of TAF in "hemifumarate" form, is under patent protection until 15.08.2032 by Gilead, and so the "monofumarate" form was used in the present study. At first, a pilot study was conducted involving 12 subjects under fed conditions. The results of the pilot study revealed the test and reference products were not bioequivalent, as a result of insufficient statistical power and high inter-subject variability. Secondly, a physiologically based pharmacokinetic (PBPK) simulation was performed based on the pilot study results and literature data. Finally, the power of the design was increased and the pivotal study design was optimized into a four-period, full-replicated, cross-over study with 34 subjects under fed conditions and it was concluded that the test and reference products were bioequivalent. In conclusion, the present study proved the importance of a correct study design with higher statistical power for a BCS Class III compound with high variability, to present the pharmacokinetics.

Tenofovir-Induced Fanconi Syndrome Presenting with Life-Threatening Hypokalemia: Review of the Literature and Recommendations for Early Detection

Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor that has been widely used for the treatment of patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. Despite the excellent safety records of this regimen, a few cases of acute renal failure and Fanconi syndrome have been reported among HIV patients exposed to TDF. However, in the HBV monoinfection scenario, only five cases of TDF-associated Fanconi syndrome have been reported thus far, two of them providing a confirmatory kidney biopsy. Here, we describe the case of a 68-year-old woman with chronic hepatitis B (CHB) who developed TDF-induced Fanconi syndrome that reverted after TDF withdrawal from tenofovir alafenamide. Though the overall risk of TDF-associated severe renal toxicity in HBV patients appears to be negligible, both glomerular and tubular functions should be monitored in patients exposed to TDF.

Longitudinal analysis of immune reconstitution and metabolic changes in women living with HIV: A real-world observational study

BACKGROUND

Women comprise more than half of people living with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) worldwide and incomplete immune recovery and metabolic abnormalities affect them deeply. Studies of HIV antiretroviral therapy (ART) have a low female representation in China. We aimed to investigate immune reconstitution and metabolic changes of female HIV-positive cohort in China longitudinally.

METHODS

HIV-positive women who initiated ART from January 2005 to June 2021 and were followed up regularly at least once a year were included in this study. Immunological indicators (cluster of differentiation 4 [CD4] counts and CD8 counts), viral load (VL), and metabolic indicators were collected at follow-up. All data were collected from the China Disease Prevention and Control Information System (CDPCIS). VL was tested half a year, 1 year after receiving ART, and every other year subsequently according to local policy. CD4/CD8 ratio normalization was considered as the primary outcome and defined as a value ≥1. Incidence rate and probability of CD4/CD8 ratio normalization were estimated through per 100 person-years follow-up (PYFU) and Kaplan-Meier curve, respectively. Multivariate Cox regression was used to identify independent risk factors associated with CD4/CD8 ratio normalization. We further studied the rate of dyslipidemia, hyperuricemia, diabetes, liver injury, and renal injury after ART initiation with the chi-squared tests or Fisher's exact probability tests, and a generalized estimating equation model was used to analyze factors of dyslipidemia and hyperuricemia.

RESULTS

A total of 494 female patients with HIV/AIDS started ART within 16 years from January 2005 to June 2021, out of which 301 women were enrolled with a median duration of ART for 4.1 years (interquartile range, 2.3-7.0 years). The overall incidence rate of CD4/CD8 ratio normalization was 8.9 (95% confidence interval [CI], 7.4-10.6) per 100 PYFU, and probabilities of CD4/CD8 normalization after initiating ART at 1 year, 2 years, 5 years, and 10 years follow-up were 11.7%, 23.2%, 44.0%, and 59.0%, respectively. Independent risk factors associated with CD4/CD8 normalization were baseline CD4 cell counts <200 cells/μL, CD8 counts >1000 cells/μL, and more than 6 months from the start of combined ART (cART) to first virological suppression. Longitudinally, the rate of hypercholesterolemia (total cholesterol [TC]) and high triglyceride (TG) showed an increasing trend, while the rate of low high-density lipoprotein cholesterol (HDL) showed a decreasing trend. The rate of hyperuricemia presented a downtrend at follow-up. Although liver and renal injury and diabetes persisted during ART, the rate was not statistically significant. Older age and protease inhibitors were independent risk factors for increase of TC and TG, and ART duration was an independent factor for elevation of TC and recovery of HDL-C.

CONCLUSIONS

This study showed that women were more likely to normalize CD4/CD8 ratio in comparison with findings reported in the literature even though immune reconstruction was incomplete.

Tenofovir-Induced Renal Dysfunction Among HIV-Infected Patients: A Systematic Review

Tenofovir disoproxil fumarate (TDF) is an antiretroviral drug widely used as part of antiretroviral therapy (ART) to treat human immunodeficiency virus (HIV-1) infection. Negative effects of tenofovir include impaired kidney function, especially with long-term use. In studies conducted among HIV-positive individuals, we found evidence of extensive kidney damage associated with TDF use. Despite the therapeutic importance of this consequence, its continued use in ART regimens was not contraindicated. The therapeutic and long-term effects of TDF are a major concern. However, in countries or settings where resources are limited and renal function monitoring cannot be ensured, screening methods to detect ART-related renal failure are still supported by data. Therefore, it is safe to re-evaluate the use of TDF-based ART. However, adherence to guidelines may be hampered by insufficient laboratory testing in low- and middle-income countries. More research is also needed among people under 18 years of age and pregnant and breastfeeding mothers.

Incidence of impaired kidney function among people with HIV: a systematic review and meta-analysis

BACKGROUND

In the era of combination antiretroviral therapy (ART), the incidence, manifestations and severity of kidney diseases have dramatically changed in people living with HIV (PLWH). Little is known about the incidence of impaired kidney function (IKF) measured by serum creatine-based estimated glomerular filtration rate (eGFR) in PLWH.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Ovid, Medline, Embase and Web of Science for studies published before May 7th, 2021, with estimates of incidence of IKF among PLWH. We independently reviewed each study for quality by using the Newcastle-Ottawa scale. The incidence and 95% confidence intervals (CIs) were calculated using random-effects model.

RESULTS

Sixty out of 3797 identifiable studies were eligible for the meta-analysis. A total of 19 definitions of IKF were described and categorized into three types: the threshold of eGFR, an absolute or percent decrease in eGFR, and certain eGFR threshold combined with decrement in eGFR. The eGFR< 60 ml/min/1.73m2 was the most widely used definition or criterion for IKF, by which the pooled incidence rate of IKF was 12.50 (95%CI: 9.00-17.36) per 1000 person years (PYs). The second most-studied outcome was a > 25% decrease in eGFR, followed by eGFR< 90 ml/min/1.73m2, eGFR< 30 ml/min/1.73m2 and a combination of eGFR threshold plus decreased eGFR. The reported incidence rates of IKF differ widely by different definitions of IKF. The highest pooled incidence was observed for those with > 25% decrease in eGFR, while the lowest was observed in those with eGFR < 30 ml/min/1.73m2. Substantial heterogeneity was identified across most estimates.

CONCLUSION

Our study provides a comprehensive summary of eGFR-based definitions and incidence rates of IKF in PLWH, not only promoting our understanding of IKF, but also underscoring needs for a concerted action to unify definitions and outcomes of IKF and their applications in AIDS care.

Evaluation of kidney function tests in HIV-positive patients receiving combined antiretroviral therapy

INTRODUCTION

Human immunodeficiency virus is a chronic infection that attacks the immune system of the human body, particularly CD4 T lymphocytes. Combined antiretroviral therapies are highly effective in virological suppression of human immunodeficiency virus infection. It has been shown that some retroviral therapies have a higher nephrotoxicity potential. As a result of renal injury, serum creatinine increases and the estimated glomerular filtration rate is reduced. The aim of our study was to assess changes in kidney function during a 24-month period in HIV-positive patients who were begun on combined antiretroviral therapy.

MATERIAL AND METHODS

A total of 127 HIV-positive patients were enrolled. The patients were divided into five groups; patients who received no therapy were designated as group 1; those who received Dolutegravir/Abacavir/Lamivudine combination as group 2; those who received Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Fumarate combination as group 3; those who received Emtricitabine/Tenofovir Disoproxil Fumarate/Dolutegravir combination as group 4; and those who received Emtricitabine/Tenofovir Disoproxil Fumarate/Raltegravir combination as group 5. We compared the effects of these drugs on estimated glomerular filtration rate during a 24-month follow-up period.

RESULTS

At the 24th month of therapy, a significant difference was observed between the estimated glomerular filtration rate (eGFR) levels of the study groups (P < .001). eGFR level was significantly higher in group 4 compared with groups 1, 2 and 3 (P = .009, P < .001, P < .001, respectively), whereas it was significantly lower in group 5 than groups 1, 2 and 3 (P = .005, P < .001, P < .001, respectively). No significant eGFR difference was found between group 4 and group 5 (P > .05). Serum creatinine level was significantly higher in groups 4 and 5 compared with the other groups (P < .001).

CONCLUSION

The use of TDF-containing regimens causes renal dysfunction. Therefore, we recommend close monitoring of renal function, especially in patients treated with TDF.