Association of tenofovir exposure with kidney disease risk in HIV infection

Proteinuria Is Associated With Increased Risk of Fragility Fracture in Men With or at Risk of HIV Infection

BACKGROUND

Proteinuria has been associated with bone loss and fractures in general population, but data in HIV-infected population are lacking.

SETTING

Prospective, multicenter cohort study of men with or at risk of HIV infection.

METHODS

Between 2006 and 2015, urine protein measurements and bone fracture histories were ascertained semiannually in 947 HIV-infected (HIV+) and 969 HIV-uninfected (HIV-) men aged 40 years or older. Proteinuria was defined as protein-to-creatinine ratio ≥200 mg/g at ≥2 consecutive visits. Outcome measures (1) all fractures (excluding fractures of skull, face, and digits) and (2) fragility fractures (fractures of vertebral column, femur, wrist, and humerus). Multivariable Cox proportional hazards models assessed the association between proteinuria and fracture after adjusting for additional risk factors.

RESULTS

The overall period prevalence of proteinuria was higher among HIV+ than HIV- (29% vs 6%, P < 0.001). Men with proteinuria had a significantly higher risk of fragility fracture compared with men without proteinuria [adjusted hazard ratio (aHR) = 2.29 (1.12-4.66)] and did not differ by HIV serostatus (p-interaction = 0.83). The risk of all fractures was not statistically different between men with or without proteinuria [aHR = 1.31 (0.84-2.05)]. Among HIV+ men, the association between confirmed proteinuria and fragility fracture was attenuated [aHR = 2.12 (0.95-4.73)] after additional adjustment for CD4 T-cell count/mm, history of AIDS, the presence of detectable plasma HIV-1 RNA, and cumulative exposure to tenofovir disoproxil fumarate.

CONCLUSIONS

Proteinuria was more common in HIV+ than in HIV- men and was a strong independent risk factor for fragility fracture regardless of HIV serostatus. Proteinuria should prompt consideration of a thorough evaluation for bone disease among HIV+ persons.

Screening for HIV Infection in Asymptomatic, Nonpregnant Adolescents and Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Untreated HIV infection can result in significant morbidity, mortality, and HIV transmission. A 2012 review for the US Preventive Services Task Force (USPSTF) found antiretroviral therapy (ART) associated with improved clinical outcomes and decreased transmission risk in persons with CD4 cell counts less than 500/mm3.

OBJECTIVE

To update the 2012 review on HIV screening to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from 2012 to June 2018, with surveillance through January 2019.

STUDY SELECTION

Nonpregnant individuals 12 years and older; randomized clinical trials (RCTs) and controlled observational studies of screening vs no screening, alternative screening strategies, earlier vs later initiation of ART, and long-term harms of ART.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data; a second checked accuracy. Two investigators independently rated study quality.

MAIN OUTCOMES AND MEASURES

Mortality, AIDS events, quality of life, function, and HIV transmission; harms of screening and long-term (≥2 years) harms of ART; screening yield.

RESULTS

Eighteen new studies (5 RCTs, 11 cohort studies, and 2 systematic reviews; N = 266 563) were included, and 11 studies (2 RCTs and 9 cohort studies; N = 218 542) were carried forward from the prior USPSTF report. No study directly evaluated effects of HIV screening vs no screening on clinical outcomes or harms, or the yield of alternative screening strategies. Two newly identified RCTs conducted completely or partially in low-resource settings found ART initiation at CD4 cell counts greater than 500/mm3 associated with lower risk of a composite outcome of mortality, AIDS-defining events, or serious non-AIDS events (relative risk [RR], 0.44 [95% CI, 0.31-0.63] and RR, 0.57 [95% CI, 0.35-0.95]); results were consistent with those from a large observational study. Early ART was not associated with increased risk of cardiovascular events. Early ART initiation was associated with sustained reduction in risk of HIV transmission at 5.5 years (RR, 0.07 [95% CI, 0.02-0.22] for linked transmission). New evidence regarding the association between abacavir use and risk of cardiovascular events was inconsistent. Certain antiretroviral regimens were associated with increased risk of long-term neuropsychiatric, renal, hepatic, and bone adverse events.

CONCLUSIONS AND RELEVANCE

In nonpregnant adolescents and adults there was no direct evidence on the clinical benefits and harms of screening for HIV infections vs no screening, or the yield of repeat or alternative screening strategies. New evidence extends effectiveness of ART to asymptomatic individuals with CD4 cell counts greater than 500/mm3 and shows sustained reduction in risk of HIV transmission at longer-term follow-up, although certain ART regimens may be associated with increased risk of long-term harms.

Owens DK, Davidson KW, Krist AH, Barry MJ, Cabana M, Caughey AB, Curry SJ, Doubeni CA, Epling JW, Kubik M, Landefeld CS, Mangione CM, Pbert L, Silverstein M, Simon MA, Tseng CW, Wong JB. Screening for HIV Infection: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Approximately 1.1 million persons in the United States are currently living with HIV, and more than 700 000 persons have died of AIDS since the first cases were reported in 1981. There were approximately 38 300 new diagnoses of HIV infection in 2017. The estimated prevalence of HIV infection among persons 13 years and older in the United States is 0.4%, and data from the Centers for Disease Control and Prevention show a significant increase in HIV diagnoses starting at age 15 years. An estimated 8700 women living with HIV give birth each year in the United States. HIV can be transmitted from mother to child during pregnancy, labor, delivery, and breastfeeding. The incidence of perinatal HIV infection in the United States peaked in 1992 and has declined significantly following the implementation of routine prenatal HIV screening and the use of effective therapies and precautions to prevent mother-to-child transmission.

OBJECTIVE

To update the 2013 US Preventive Services Task Force (USPSTF) recommendation on screening for HIV infection in adolescents, adults, and pregnant women.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the benefits and harms of screening for HIV infection in nonpregnant adolescents and adults, the yield of screening for HIV infection at different intervals, the effects of initiating antiretroviral therapy (ART) at a higher vs lower CD4 cell count, and the longer-term harms associated with currently recommended ART regimens. The USPSTF also reviewed the evidence on the benefits (specifically, reduced risk of mother-to-child transmission of HIV infection) and harms of screening for HIV infection in pregnant persons, the yield of repeat screening for HIV at different intervals during pregnancy, the effectiveness of currently recommended ART regimens for reducing mother-to-child transmission of HIV infection, and the harms of ART during pregnancy to the mother and infant.

FINDINGS

The USPSTF found convincing evidence that currently recommended HIV tests are highly accurate in diagnosing HIV infection. The USPSTF found convincing evidence that identification and early treatment of HIV infection is of substantial benefit in reducing the risk of AIDS-related events or death. The USPSTF found convincing evidence that the use of ART is of substantial benefit in decreasing the risk of HIV transmission to uninfected sex partners. The USPSTF also found convincing evidence that identification and treatment of pregnant women living with HIV infection is of substantial benefit in reducing the rate of mother-to-child transmission. The USPSTF found adequate evidence that ART is associated with some harms, including neuropsychiatric, renal, and hepatic harms, and an increased risk of preterm birth in pregnant women. The USPSTF concludes with high certainty that the net benefit of screening for HIV infection in adolescents, adults, and pregnant women is substantial.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends screening for HIV infection in adolescents and adults aged 15 to 65 years. Younger adolescents and older adults who are at increased risk of infection should also be screened. (A recommendation) The USPSTF recommends screening for HIV infection in all pregnant persons, including those who present in labor or at delivery whose HIV status is unknown. (A recommendation).

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Chronic kidney disease and HIV in the era of antiretroviral treatment: findings from a 10-year cohort study in a west African setting

Background

It has been reported that people living with HIV in West Africa exhibited the highest risks for chronic kidney disease (CKD) in the world. Here, we aimed at determining the CKD frequency and changes in kidney function during antiretroviral treatment (ART) in a large cohort of HIV-patients followed in Burkina Faso.

Methods

We included ART-naive adults who initiated ART at the Day Care Unit of the Souro Sanou University Hospital between 01/01/2007 and 12/31/2016. We assessed the estimated glomerular filtration rate (eGFR) by serum creatinine using the Modification of Diet in Renal Disease (MDRD) equation. Following the K/DOQI recommendations, CKD was defined as eGFR < 60 ml/min/1.73m² at two consecutive measurements at least 3 months apart. The factors associated with eGFR decline or CKD were identified by mixed linear regression and Cox regression, respectively.

Results

Three thousand, one hundred and thirty-eight patients (72% women) were followed for a median (IQR) of 4.5(2.2–6.9) years. At baseline, median eGFR (IQR) was 110.7(94.4–128.4) ml/min/1.73m² and 93 (3%) patients exhibited eGFR < 60 ml/min/1.73m². The lowest-performing progressions of eGFR during the first year of ART were observed in patients with 40-49 yr. age range (− 8.3[− 11.7;-5.0] ml/min/1.73m², p < 0.001), age ≥ 50 yr. (− 6.2[− 10.7;-1.8] ml/min/1.73m², p = 0.006) and high blood pressure (HBP) (− 28.4[− 46.9;-9.9] ml/min/1.73m², p = 0.003) at ART initiation. Regarding the ART exposure in patients with normal baseline eGFR, zidovudine (AZT) with protease inhibitor (PI) (− 4.7[− 7.7;-1.6] ml/min/1.73m², p = 0.002), tenofovir (TDF) + PI (− 13.1[− 17.4;-8.7] ml/min/1.73m², p < 0.001), TDF without PI (− 3.2[− 5.0;-1.4] ml/min/1.73m², p < 0.001), stavudine (d4T) + PI (− 8.5[− 14.6–2.4] ml/min/1.73m², p = 0.006) and d4T without PI (− 5.0[− 7.6–2.4] ml/min/1.73m², p < 0.001) were associated with poorer eGFR progression. The prevalence of CKD was 0.5% and the incidence was 1.9 [1.3; 2.7] cases/1000 person-years. The risk of CKD was higher in patients with HBP (4.3[1.8;9.9], p = 0.001), 40-49 yr. patients (4.2[1.6;11.2], p = 0.004), ≥50 yr. patients (4.5[1.5;14.1], p = 0.009) and patients exposed to abacavir (ABC) or didanosine (ddI) based ART (13.1[4.0;42.9], p < 0.001).

Conclusions

Our findings do not confirm the high risk of CKD reported in previous studies of West Africans with HIV, but support the recommendations for early initiation of ART and close kidney function monitoring in patients with HBP or aged ≥40 yr.

Pre-exposure Prophylaxis With Tenofovir Disoproxil Fumarate/Emtricitabine and Kidney Tubular Dysfunction in HIV-Uninfected Individuals

BACKGROUND

Pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) is becoming increasingly adopted for HIV prevention. Tenofovir can cause proximal tubular damage and chronic kidney disease in HIV-infected persons, but little is known regarding its nephrotoxic potential among HIV-uninfected persons. In this study, we evaluated the effects of PrEP on urine levels of the following: α1-microglobulin (α1m), a marker of impaired tubular reabsorption; albuminuria, a measure of glomerular injury; and total proteinuria.

SETTING

The Iniciativa Profilaxis Pre-Exposicion (iPrEx) study randomized HIV-seronegative men and transgender women who have sex with men to oral TDF/FTC or placebo. The iPrEx open-label extension (iPrEx-OLE) study enrolled former PrEP trial participants to receive open-label TDF/FTC.

METHODS

A cross-sectional analysis compared urine biomarker levels by study arm in iPrEx (N = 100 treatment arm, N = 100 placebo arm). Then, urine biomarker levels were compared before and after PrEP initiation in 109 participants of iPrEx-OLE.

RESULTS

In iPrEx, there were no significant differences in urine α1m, albuminuria, or proteinuria by treatment arm. In iPrEx-OLE, after 24 weeks on PrEP, urine α1m and proteinuria increased by 21% [95% confidence interval (CI): 10 to 33] and 18% (95% CI: 8 to 28), respectively. The prevalence of detectable α1m increased from 44% to 65% (P < 0.001) and estimated glomerular filtration rate declined by 4 mL/min/1.73 m (P < 0.001). There was no significant change in albuminuria (6%; 95% CI: -7% to 20%).

CONCLUSION

PrEP with TDF/FTC was associated with a statistically significant rise in urine α1m and proteinuria after 6 months, suggesting that PrEP may result in subclinical tubule dysfunction.

The Changing Face of Human Immunodeficiency Virus-Mediated Kidney Disease

In nearly 40 years since human immunodeficiency virus (HIV) first emerged, much has changed. Our understanding of the pathogenesis of HIV infection and its effect on the cells within each kidney compartment has progressed, and the natural history of the disease has been transformed. What was once an acutely fatal illness is now a chronic disease managed with oral medications. This change is largely due to the advent of antiretroviral drugs, which have dramatically altered the prognosis and progression of HIV infection. However, the success of antiretroviral therapy has brought with it new challenges for the nephrologist caring for patients with HIV/acquired immune deficiency syndrome, including antiretroviral therapy-induced nephrotoxicity, development of non-HIV chronic kidney disease, and rising incidence of immune-mediated kidney injury. In this review, we discuss the pathogenesis of HIV infection and how it causes pathologic changes in the kidney, review the nephrotoxic effects of select antiretroviral medications, and touch upon other causes of kidney injury in HIV cases, including mechanisms of acute kidney injury, HIV-related immune complex glomerular disease, and thrombotic microangiopathy.

Adverse outcome pathway for aminoglycoside ototoxicity in drug-resistant tuberculosis treatment

Individuals treated for multidrug-resistant tuberculosis (MDR-TB) with aminoglycosides (AGs) in resource-limited settings often experience permanent hearing loss. However, AG ototoxicity has never been conceptually integrated or causally linked to MDR-TB patients' pre-treatment health condition. We sought to develop a framework that examines the relationships between pre-treatment conditions and AG-induced hearing loss among MDR-TB-infected individuals in sub-Saharan Africa. The adverse outcome pathway (AOP) approach was used to develop a framework linking key events (KEs) within a biological pathway that results in adverse outcomes (AO), which are associated with chemical perturbation of a molecular initiating event (MIE). This AOP describes pathways initiating from AG accumulation in hair cells, sound transducers of the inner ear immediately after AG administration. After administration, the drug catalyzes cellular oxidative stress due to overproduction of reactive oxygen species. Since oxidative stress inhibits mitochondrial protein synthesis, hair cells undergo apoptotic cell death, resulting in irreversible hearing loss (AO). We identified the following pre-treatment conditions that worsen the causal linkage between MIE and AO: HIV, malnutrition, aging, noise, smoking, and alcohol use. The KEs are: (1) nephrotoxicity, pre-existing hearing loss, and hypoalbuminemia that catalyzes AG accumulation; (2) immunodeficiency and antioxidant deficiency that trigger oxidative stress pathways; and (3) co-administration of mitochondrial toxic drugs that hinder mitochondrial protein synthesis, causing apoptosis. This AOP clearly warrants the development of personalized interventions for patients undergoing MDR-TB treatment. Such interventions (i.e., choosing less ototoxic drugs, scheduling frequent monitoring, modifying nutritional status, avoiding poly-pharmacy) will be required to limit the burden of AG ototoxicity.

Rosuvastatin and atorvastatin preserve renal function in HIV-1-infected patients with chronic kidney disease and hyperlipidaemia

BACKGROUND

Hyperlipidaemia is a risk factor for the progression of chronic kidney disease (CKD), which is a frequent comorbidity in patients with HIV-1 infection, but the renal effects of statins remain unclear.

METHODS

We performed an observational, prospective study of HIV-infected patients on suppressive antiretroviral therapy, with CKD and hyperlipidaemia, and starting a lipid-lowering treatment with rosuvastatin, atorvastatin or omega-3 fatty acids. CKD was defined as an estimated glomerular filtration rate (eGFR) ≤ 60 mL/min/1.73 m² for >3 months.

RESULTS

As a whole, 69 patients (53 men, 58 Caucasian, median age 56.2 years) were enrolled. Overall, 25 patients started rosuvastatin (10 mg daily, group A), 23 patients atorvastatin (20 mg daily, group B), and 21 started omega-3 fatty acids (3 g daily, group C). At baseline, median eGFR was 54.4 mL/min/1.73 m², and the eGFR ranged between 50 and 60 mL/min/1.73 m² in 87% of patients. After 12 months, the median eGFR decline was significantly lower in group A (-0.84 mL/min/1.73 m²) and in group B (-0.91 mL/min/1.73 m²) in comparison with the group C (-1.53 mL/min/1.73 m²; p < 0.001 for both comparisons). The median decrease in prevalence of proteinuria and high-sensitivity C-reactive protein was also significantly greater in groups A and B than in group C, while the incidence of treatment discontinuations was comparable across the three groups.

CONCLUSION

In our study, rosuvastatin and atorvastatin showed a significant protective effect on the renal function compared to omega-3 fatty acids in HIV-1-infected patients with CKD and dyslipidaemia.

Effectiveness and safety of dual therapy with rilpivirine and boosted darunavir in treatment-experienced patients with advanced HIV infection: a preliminary 24 week analysis (RIDAR study)

Background

The objective was to analyze the effectiveness and safety of dual therapy with rilpivirine plus boosted-darunavir (RPV + bDRV) in real-life patients.

Methods

Observational, retrospective, multi-center study in HIV+ patients who had received RPV + bDRV for 24 weeks to optimize/simplify their previous antiretroviral treatment. We determined the percentage of patients without virologic failure (2 consecutive viral loads > 50 copies/mL) at 24 weeks of treatment.

Results

The study included 161 patients from 15 hospitals with median age of 49 years; 29.3% had previous AIDS stage and median CD4+ lymphocyte nadir of 170 cells/uL. They had been diagnosed with HIV for a median of 17 years and had received 14 years of ART, with five previous treatment combinations, and 36.6% had a history of virological failure. The reasons for the switch were simplification/optimization (49.7%), toxicity/intolerance (17.4%), or inadequate effectiveness of previous ART (10.6%).

Baseline VL of 50–1000 copies/mL was recorded in 25.5% of the patients. In the“intention-to-treat” analysis at 24 weeks, 87.6% of 161 patients continued the study treatment without virologic failure criteria.

In the “on treatment” analysis (excluding patients who discontinued treatment with dual therapy for any reason other than virologic failure) the efficacy was 94.6% (141/149 patients).

Conclusions

Dual therapy with RPV + DRVb proved to be effective and safe in patients with advanced HIV infection, long exposure to ART, low CD4 nadir, previous virologic failure, and/or history of ineffective ART.

Severe rhabdomyolysis-induced acute kidney injury following concomitant use of Genvoya® (EVG/COBI/FTC/TAF) and simvastatin; a case report

Background

Genvoya® (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide) is a recent single regimen for the treatment of Human Immunodeficiency Virus (HIV). However, because of its complexity, it is difficult to predict drug interactions, especially when associated with HMG-CoA reductase inhibitors and/or in the setting of other comorbidities. We discuss the mechanisms of these potential drug interactions as the cause of rhabdomyolysis and acute kidney injury in the context of prior and current medication therapy with possible underlying liver and kidney dysfunction.

Case presentation

We describe the case of a 54-year-old man diagnosed with HIV who developed severe rhabdomyolysis-induced anuric acute kidney injury (AKI) requiring renal replacement therapy following introduction of Genvoya® concomitantly with simvastatin, in the context of recently diagnosed hepatitis C and hepatitis A. Haemodialysis was continued over 5 weeks followed by progressive clinical and biological improvements. Five months later, a new antiretroviral regimen was started and has been well tolerated.

Conclusion

Simvastatin, as well as lovastatin, because of their CYP3A4 metabolism, and to a lesser extent atorvastatin, which is only partially metabolized by CYP3A4, are the HMG-CoA reductase inhibitors with the greatest risk of drug interactions and should not be used in patients under HIV-therapy. Patients receiving HMG-CoA reductase inhibitors should be monitored regularly for the occurrence of muscular adverse effects and drug interactions should be considered with each new prescription or change in clinical status. There are many online tools that enable clinicians to rapidly check for drug interactions. We recommend the one from the University of Liverpool for patients under HIV-therapy (https://www.hiv-druginteractions.org/checker), while for patients under hepatitis C-therapy, we advise to consult http://www.hep-druginteractions.org/. This case illustrates the importance of multidisciplinary collaboration in the treatment of HIV-positive patients because of their complexity, associated comorbidities and the potential of multiple drug-drug interactions potentially exacerbated by underlying liver and/or kidney dysfunction.

Brief Report: Tenofovir-Associated Nephrotoxicity Among a US National Historical Cohort of HIV-Infected Veterans: Risk Modification by Concomitant Antiretrovirals

BACKGROUND

Tenofovir disoproxil fumarate (TDF) has been associated with renal complications. The third agent in TDF-containing antiretroviral regimens may modify that risk. We compared renal adverse outcomes among treatment-naive HIV-infected patients initiating TDF-containing regimens including efavirenz (EFV) or other agents.

SETTING

This population-based historical cohort study used national Veterans Health Administration (VHA) clinical and administrative data sets to identify treatment-naive HIV-infected veterans initiating antiretroviral therapy with TDF/emtricitabine (FTC) + EFV, rilpivirine (RPV), elvitegravir/cobicistat (EVG/c), or ritonavir (RTV)-boosted protease inhibitors (PIs) from 2003 to 2015.

METHODS

Unadjusted incidence rates (IRs) for each regimen and covariate-adjusted hazard ratios [ using Cox proportional hazards models and inverse probability of treatment weighting] for between-regimen comparisons were calculated for renal outcomes including confirmed proteinuria, defined as 2 consecutive protein-to-creatinine ratios >150 mg/g or albumin-to-creatinine ratios >30 mg/g occurring ≥90 days apart; chronic kidney disease (CKD), defined as 2 consecutive estimated glomerular filtration rate measurements <60 mL·min·1.73 m occurring ≥90 days apart; and kidney dialysis.

RESULTS

Of 33,048 HIV-positive veterans, 4172 received EFV + TDF/FTC, 234 EVG/c/TDF/FTC, 173 RPV/TDF/FTC, and 2651 RTV-boosted PIs + TDF/FTC. Confirmed proteinuria and CKD IRs were numerically lower with EFV + TDF/FTC versus non-EFV + TDF/FTC (dialysis IRs were rare and comparable). After inverse probability of treatment weighting adjustment, EFV + TDF/FTC was associated with lower CKD risk versus non-EFV + TDF/FTC (hazard ratio, 0.62; 95% confidence interval, 0.53 to 0.72), EVG/c/TDF/FTC (0.75; 0.59 to 0.95), RPV/TDF/FTC (0.20; 0.17 to 0.24), and RTV-boosted PIs + TDF/FTC (0.62; 0.53 to 0.72).

CONCLUSIONS

EFV + TDF/FTC was associated with significantly lower risk of CKD versus other TDF-containing regimens in the Veterans Health Administration.

Changing concepts of HIV infection and renal disease

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) was identified as the major renal manifestation of HIV infection early in the HIV epidemic. However, HIV infection now is associated with a different spectrum of renal lesions leading to chronic kidney disease. This review examines the changes in kidney injury occurring in the current HIV era and the factors involved in this transformation of disease expression.

RECENT FINDINGS

The incidence of HIVAN and opportunistic infections in HIV-infected individuals has declined in concert with the use of effective combination antiretroviral agents. Chronic kidney disease has become more prevalent as patients infected with HIV are living longer and developing non-HIV-associated diseases such as hypertension and diabetes. Additionally, noncollapsing focal and segmental glomerulosclerosis, co-infection with hepatitis C, HIV-associated immune complex kidney disease, HIV-related accelerated aging, and antiretroviral therapies contribute to progressive loss of renal function.

SUMMARY

HIV infection is now associated with a variety of renal lesions causing chronic kidney disease, not all of which are virally induced. It is important to determine the cause of renal functional decline in an HIV-infected patient, as this will impact patient management and prognosis.

Membranous Nephropathy in a Patient with Human Immunodeficiency Virus Shortly After Initiation of HAART with Atripla

A human immunodeficiency virus (HIV) infection has long been associated with kidney disease. The pathogenesis of renal complications may be directly related to the presence of HIV viral particles or may occur secondary to an immune response against the virus. A number of HIV medications have been associated with the development of acute and chronic kidney disease. It has been estimated that approximately 60 percent of patients suffering from HIV/acquired immunodeficiency syndrome (AIDS) will, at some point, manifest clinically significant renal sequelae.The most common kidney disease affecting HIV patients is HIV-associated nephropathy (HIVAN) or focal segmental glomerulonephritis (FSGS). A very small subset of patients suffering from HIV/AIDS does go on to develop membranous glomerulonephritis. We present a case of a 55-year old Caucasian male who presented to the hospital after two weeks of weakness and falling when attempting to stand. The patient had a history of HIV, diagnosed in 1996. The latest cluster differentiation 4 (CD4) count was 245 cells/uL and the HIV-ribonucleic acid (RNA) viral load was reported as less than 75 copies/ml. The physical exam at presentation was insignificant. The laboratory examination revealed elevated creatinine. Potential nephrotoxic home medications, including Atripla and lisinopril, were held. After a brief inpatient stay, he was discharged but was ultimately readmitted for worsening renal function and nephrotic syndrome was diagnosed. Renal biopsy was performed, and membranous glomerulonephritis was confirmed. To this point, there are no associated cases reported of membranous glomerulonephritis after initiation of therapy with Atripla.

We present a case of a rare etiology of membranous nephropathy in an HIV patient. Physicians should be judicious in detecting the etiology of renal dysfunction in HIV patients.

Kidney disease risk factors associate with urine biomarkers concentrations in HIV-positive persons; a cross-sectional study

Background

HIV-positive persons bear an excess burden of chronic kidney disease (CKD); however, conventional methods to assess kidney health are insensitive and non-specific for detecting early kidney injury. Urinary biomarkers can detect early kidney injury, and may help mitigate the risk of overt CKD.

Methods

Cross-sectional study of HIV-positive persons in the Multicenter AIDS Cohort Study and the Women’s Interagency HIV Study. We measured levels of 14 biomarkers, capturing multiple dimensions of kidney injury. We then evaluated associations of known CKD risk factors with urine biomarkers using separate multivariable adjusted models for each biomarker.

Results

Of the 198 participants, one third were on HAART and virally suppressed. The vast majority (95%) had preserved kidney function as assessed by serum creatinine, with a median eGFR of 103 ml/min/1.73 m² (interquartile range (IQR): 88, 116). In our multivariable analyses, the associations of each CKD risk factor with urinary biomarker levels varied in magnitude. For example, HIV viral load was predominantly associated with elevations in interleukin(IL)-18, and albuminuria, while higher CD4 levels were associated with lower monocyte chemoattractant protein-1 (MCP-1) and β2-microglobulin. In contrast, older age was significantly associated with elevations in α1-microglobulin, kidney injury marker-1, clusterin, MCP-1, and chitinase-3-like protein-1 levels, as well as lower epidermal growth factor, and uromodulin levels.

Conclusions

Among HIV-positive persons, CKD risk factors are associated with unique and heterogeneous patterns of changes in urine biomarkers levels. Additional work is needed to develop parsimonious algorithms that integrate multiple biomarkers and clinical data to discern the risk of overt CKD and its progression.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1192-y) contains supplementary material, which is available to authorized users.

Long Term Exposure to Tenofovir Disoproxil Fumarate-Containing Antiretroviral Therapy Is Associated with Renal Impairment in an African Cohort of HIV-Infected Adults

OBJECTIVES AND METHOD

There are growing concerns of tenofovir disoproxil fumarate (TDF)-associated renal toxicity. We evaluated the effect of long-term TDF exposure on renal function in a cohort of HIV-1-infected Nigerians between 2006 and 2015. Multivariate logistic regression was used to identify predictors of renal impairment at different time over 144 weeks of antiretroviral therapy (ART).

RESULTS

Data of 4897 patients, median age 42 years (interquartile range: 36-49), and 61% females were analyzed. The prevalence of renal impairment increased from 10% at week 24 to 45% at 144 weeks in TDF-exposed participants compared to an increase from 8% at 24 weeks to 14% at 144 weeks in TDF-unexposed participants. Tenofovir disoproxil fumarate exposure predicted the risk of renal impairment at 144 weeks of ART (odds ratio: 2.36; 95% confidence interval: 1.28-4.34).

CONCLUSION

Long-term exposure to TDF-based ART significantly increases the likelihood of renal impairment. The continued use of TDF-based regimen in our setting should be reviewed. We recommend the urgent introduction of tenofovir alafenamide-based regimen in the HIV treatment guidelines of Nigeria and other resource-limited countries.

Health Care Costs in a Cohort of HIV-Infected U.S. Veterans Receiving Regimens Containing Tenofovir Disoproxil Fumarate/Emtricitabine

BACKGROUND

Tenofovir disoproxil fumarate (TDF), a key component in many human immunodeficiency virus (HIV) treatment regimens, is associated with increased renal and bone toxicities. The contributions of such toxicities to treatment costs, as well as the relative differences in treatment costs for various TDF/emtricitabine (FTC) regimens, remains unexplored.

OBJECTIVE

To estimate and compare mean overall and renal- and bone-specific costs, including total, inpatient, outpatient, and pharmacy costs in patients treated with TDF/FTC+efavirenz (EFV) compared with several non-EFV-containing TDF/FTC regimens.

METHODS

We conducted a national cohort study of treatment-naive HIV-infected U.S. veterans who initiated treatment from 2003 to 2015 with TDF/FTC in combination with EFV, elvitegravir/cobicistat, rilpivirine, or ritonavir-boosted protease inhibitors (atazanavir, darunavir, or lopinavir). Outcomes of interest were quarterly total, inpatient, outpatient, and pharmacy costs using data from the Veterans Health Administration (VHA) electronic medical record and Managerial Cost Accounting System (an activity-based accounting system that allocates VHA expenditures to patient encounters). We controlled for measured confounders using inverse probability of treatment (IPT) weights and assessed differences using standardized mean differences (SMDs). For comparisons where SMDs exceeded 0.1 after IPT weighting, we used the more conservative matching weights in sensitivity analyses. For hypothesis testing, we compared IPT-adjusted differences in quarterly costs between treatment groups using Mann-Whitney U-tests and generalized estimating equation (GEE) regression models.

RESULTS

Of 33,048 HIV-positive veterans, 7,222 met eligibility criteria, including 4,172 TDF/FTC + EFV recipients; mean (SD) age of the cohort was 50.0 (10.0) years; 96.7% were male; 60.1% were black; and 30.1% were white. Quarterly periods of exposure to EFV-containing regimens were 22,499 and of exposure to non-EFV-containing regimens were 11,633. After IPT weighting, absolute SMDs were < 0.1 except for a few covariates in the rilpivirine comparison. The per-patient adjusted mean total quarterly costs were $7,145 for EFV versus $8,726 for non-EFV (P < 0.001; Mann-Whitney U-test) and the per-patient adjusted mean difference in total quarterly costs was $1,419 lower for EFV versus all non-EFV combined (P < 0.001; GEE model). Corresponding values for outpatient costs ($2,656 vs. $2,942; P < 0.001; difference, -$254; P = 0.001), inpatient costs ($2,009 vs. $2,614; P < 0.001), radiology costs ($213 vs. $276; P < 0.001), and pharmacy costs ($2,480 vs. $3,170; P < 0.001; difference, -$600; P < 0.001) were all lower for EFV versus all non-EFV combined. Findings based on matching weights were qualitatively similar. Contributions of renal and bone costs to the total costs of treatment were very small, ranging between $52 and $94 per patient per quarter for renal outcomes and between $6 and $114 for bone outcomes.

CONCLUSIONS

Among 7,222 HIV-treated veterans over an average follow-up of 1.2 years per patient, those patients receiving TDF/FTC + EFV had lower overall health care costs compared with those receiving non-EFV regimens.

DISCLOSURES

This study was funded by Bristol-Myers Squibb. Nelson, Ma, Crook, Knippenberg, Nyman, and LaFleur are employees of the University of Utah, which received a grant from Bristol-Myers Squibb to conduct this study. Nyman also discloses honoraria for consulting from Otsuka and for writing a book chapter from Fresenius. La Fleur reports advisory board and consulting fees from Bristol-Myers Squibb outside of this study. Paul and Esker are employees of, and own stock in, Bristol-Myers Squibb.

Tenofovir disoproxil fumarate discontinuation for renal outcomes: any room for treatment personalization?

Tenofovir disoproxil fumarate (TDF) is a very effective antiviral drug that has been associated with tubular dysfunction. The aim of this study was to analyze the demographic, pharmacokinetic, and pharmacogenetic variables associated with TDF discontinuation for renal outcomes in stable HIV-positive patients using multivariable analyses. Three hundred and four patients were included (73% male, with median age and eCrCl of 45.3 years and 90.9 mL/min, respectively). After a median follow-up of 28.3 months, 27 patients discontinued TDF for renal adverse events [persistent urinary abnormalities (n = 21) or eCrCl < 60 mL/min (n = 6)] providing an incidence of 3.77 events per 100 patient-year. The probability of TDF discontinuation was higher with several features (male gender, older age, not Caucasians ancestry, absence of intravenous drug abuse, protease inhibitors, previous indinavir, HCV-positivity, lower CD4 cell count, detectable HIV-RNA, lower eCrCl, spot-urine proteinuria) and higher tenofovir concentrations but not genetic variants. Tenofovir plasma concentrations were prognostic of TDF discontinuation for renal adverse events suggesting that dose-adjustment may be warranted for long-term safety.

Mitochondrial pathway of apoptosis and necrosis contribute to tenofovir disoproxil fumarate-induced renal damage in rats

Tenofovir disoproxil fumarate (TDF) is currently the only nucleotide analogue reverse-transcriptase inhibitor that is approved by the Food and Drug administration (FDA), USA, for the treatment of human immunodeficiency virus (HIV) infection. In recent days, renal toxicity is becoming common i HIV patients treated with TDF. However, the mechanism of tenofovir nephrotoxicity is not clear. We hypothesized that mitochondrial pathway of apoptosis, poly [ADP-ribose] polymerase (PARP) overactivation and neutrophil infiltration may contribute to tenofovir-induced renal damage. Renal damage was induced in adult male Wistar rats by the oral administration of 600 mg/kg body weight daily for five consecutive weeks. Kidneys were removed and used for histological and biochemical analyses. Apoptosis was detected by terminal deoxynucleotidyl transferase biotin-deoxyuridine triphosphate nick end-labelling (TUNEL) assay and caspase 3 activity and protein expression; mitochondrial pathway of apoptosis by cyt c release; and PARP activation by immunofluorescence, immunohistochemistry and Western blot techniques. Myeloperoxidase (MPO) activity was measured as a marker of neutrophil infiltration. TDF administration resulted in increased number of TUNEL-positive cells, activation of caspase 3 and release of cyt c from mitochondria into the cytosol in the kidneys. There was increased nuclear localization of PARP as well as increase in its protein level in the TDF-treated rat kidneys. In addition, renal MPO activity was increased ninefold as compared to controls. The results of the present study show that mitochondrial apoptotic pathway, PARP overactivation and neutrophil infiltration contribute to tenofovir-induced renal damage in rats.

Tenofovir-induced renal tubular dysfunction among human immunodeficiency virus patients on antiretroviral therapy in Nigeria: Prospects for early detection of presymptomatic nephrotoxicity

Background

Tenofovir disoproxil fumarate (TDF) is relatively safe, although renal toxicity has been reported. In Nigeria, there is insufficient data on renal toxicity among patients on TDF. This study assesses TDF-associated tubular dysfunction among human immunodeficiency virus (HIV) patients at a hospital in Nigeria.

Methods

In this cohort study, 104 adult HIV patients were recruited with a simple random technique from the outpatient clinic. Biochemical indices of renal function were estimated from serum and urine at the 16th and 24th week after an initial assessment at baseline.

Results

There were no significant differences in baseline proteinuria or glycosuria between TDF and non-TDF groups. Mean baseline urine and serum parameters did not differ significantly between the two groups (P > 0.05). In the TDF group, all urine parameters differed significantly between baseline and 24th week values (P < 0.001). After 16 weeks, mean urine phosphate and urine uric acid increased significantly (P < 0.05) by 2.97 mg/dL and 50.9 mg/dL, respectively, in the TDF group. The rise in mean urine glucose from baseline to the 24th week was more marked in the TDF than the non-TDF group (0.25 vs. 0.07 mmol/L). Higher mean differences in urine albumin were also recorded in the TDF group from baseline to the 24th week.

Conclusion

Indicators of tubular dysfunction were markedly higher among patients on the TDF-based treatment regimen. Biomarkers of tubular dysfunction could be useful for detecting pre-symptomatic nephrotoxicity before marked reduction of glomerular filtration rate in HIV patients on TDF.

Association of Urinary Biomarkers of Kidney Injury with Estimated GFR Decline in HIV-Infected Individuals following Tenofovir Disoproxil Fumarate Initiation

BACKGROUND AND OBJECTIVES

Tenofovir disoproxil fumarate (tenofovir) is associated with elevated concentrations of biomarkers of kidney damage and dysfunction in individuals with HIV. The relationship of these kidney biomarkers with longitudinal kidney function decline is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We evaluated associations of 14 urinary biomarkers of kidney injury with changes in eGFR among 198 men and women with HIV who initiated tenofovir between 2009 and 2015 in the Multicenter AIDS Cohort Study and Women's Interagency HIV Study. Urinary biomarkers included albumin-to-creatinine ratio, α-1-microglobulin, β-2-microglobulin, cystatin C, kidney injury molecule-1 (KIM-1), IL-18, neutrophil gelatinase-associated lipocalin (NGAL), clusterin, osteopontin, uromodulin, monocyte chemoattractant protein-1, EGF, trefoil factor 3, and chitinase 3-like protein 1. We used multivariable linear mixed-effect models controlling for demographics, traditional kidney disease risk factors, and HIV-related risk factors to evaluate associations of baseline biomarkers with first-year changes in eGFR, and associations of year 1 and first-year change in biomarkers with changes in eGFR from year 1 to year 3. We used the least absolute shrinkage and selection operator method to identify a parsimonious set of biomarkers jointly associated with changes in eGFR.

RESULTS

Median eGFR before tenofovir initiation was 103 (interquartile range, 88-116) ml/min per 1.73 m2. During the first year of tenofovir use, eGFR decreased on average by 9.2 (95% confidence interval, 6.5 to 11.9) ml/min per 1.73 m2 and was stable afterward (decrease of 0.62; 95% confidence interval, -0.85 to 2.1 ml/min per 1.73 m2 per year). After multivariable adjustment, higher baseline β-2-microglobulin, KIM-1, and clusterin were associated with larger first-year eGFR declines, whereas higher baseline uromodulin was associated with a smaller eGFR decline. First-year increase in urinary cystatin C and higher year 1 IL-18 were associated with larger annual eGFR declines from year 1 to year 3. The parsimonious models identified higher pre-tenofovir clusterin and KIM-1, lower pre-tenofovir uromodulin, and higher year 1 IL-18 as jointly associated with larger eGFR declines.

CONCLUSIONS

Urinary biomarkers of kidney injury measured before and after tenofovir initiation are associated with subsequent changes in eGFR in individuals with HIV.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_08_28_CJASNPodcast_18_9_S.mp3.

Proximal Tubular Secretory Clearance: A Neglected Partner of Kidney Function

The secretion of small molecules by the proximal tubules of the kidneys represents a vital homeostatic function for rapidly clearing endogenous solutes and medications from the circulation. After filtration at the glomerulus, renal blood flow is directed through a network of peritubular capillaries, where transporters of the proximal tubules actively secrete putative uremic toxins and hundreds of commonly prescribed drugs into the urine, including protein-bound substances that cannot readily cross the glomerular basement membrane. Despite its central physiologic importance, tubular secretory clearance is rarely measured or even estimated in clinical or research settings. Major barriers to estimating tubular solute clearance include uncertainty regarding optimal endogenous secretory markers and a lack of standardized laboratory assays. The creation of new methods to measure tubular secretion could catalyze advances in kidney disease research and clinical care. Differences in secretory clearance relative to the GFR could help distinguish among the causes of CKD, particularly for disorders that primarily affect the tubulointerstitium. As the primary mechanism by which the kidneys excrete medications, tubular secretory clearance offers promise for improving kidney medication dosing, which is currently exclusively on the basis of filtration. The differing metabolic profiles of retained solutes eliminated by secretion versus glomerular filtration suggest that secretory clearance could uniquely inform uremic toxicity, refine existing measures of residual kidney function, and improve prediction of cardiovascular and kidney disease outcomes. Interdisciplinary research across clinical, translational, and laboratory medicine is needed to bring this often neglected kidney function into the limelight.

Secondary Syphilis Associated with Membranous Nephropathy and Acute Hepatitis in a Patient with HIV: A Case Report

INTRODUCTION

We present a case of membranous nephropathy associated with a secondary syphilis infection in a patient with HIV.

CASE PRESENTATION

A 37-year-old white man with HIV who was receiving highly active antiretroviral therapy presented to the Emergency Department with 6 weeks of rectal pain. He had a CD3-CD4 count of 656 cells/mm³ and an undetectable viral load. On admission, he was found to have an anal ulcer, a serum creatinine of 1.4 mg/dL (baseline 0.7 to 1.0 mg/dL), elevated transaminases, positive rapid plasmin reagin, and a urine protein/creatinine ratio revealing nephrotic-range proteinuria. Renal biopsy demonstrated membranous nephropathy with features suggestive of a secondary cause. Our patient was treated with penicillin for secondary syphilis, with normalization of renal function, resolution of the nephrotic syndrome, and improvement of his elevated transaminases.

DISCUSSION

This case is a reminder that patients with HIV are not infrequently coinfected with Treponema pallidum and that secondary syphilis can have systemic manifestations, including elevated transaminases and nephrotic syndrome. Prompt diagnosis and treatment will result in resolution of these problems.

An overview of tenofovir and renal disease for the HIV-treating clinician

Tenofovir disoproxil fumarate (TDF, commonly termed ‘tenofovir’) is the antiretroviral most commonly implicated in antiretroviral-induced nephrotoxicity. As patients on successful antiretroviral therapy (ART) age, their risk for developing renal disease may increase in part because of ART itself, but more importantly, because of HIV-associated and non-HIV-associated comorbidity. Therefore, clinicians need an approach to managing renal disease in people on TDF. TDF as a cause of acute kidney injury (AKI) or chronic kidney disease (CKD) is uncommon, and clinicians should actively exclude other causes (Box 1). In TDF-associated AKI, TDF should be interrupted in all cases, and replaced, or ART interrupted altogether. Tenofovir disoproxil fumarate toxicity can present as AKI or CKD, and as a full or partial Fanconi’s syndrome. TDF has a small but definite negative impact on kidney function (up to a 10% decrease in glomerular filtration rate [GFR]). This occurs because of altered tubular function in those exposed to TDF for treatment and as pre-exposure prophylaxis. Renal function should be assessed using creatinine-based estimated GFR at the time of initiation of TDF, if ART is changed, at 1–3 months, and then ideally every 6–12 months if stable. Specific tests of tubular function are not routinely recommended; in the case of clinical concern, a spot protein or albumin: creatinine ratio is preferable, but in resource-limited settings, urine dipstick can be used. More frequent monitoring may be required in those with established CKD (estimated glomerular filtration rate [eGFR] < 50 mL/min/1.73 m²) or risk factors for kidney disease. The most common risk factors are comorbid hypertension, diabetes, HIV-associated kidney disease, hepatitis B or C co-infection, and TDF in combination with a ritonavir-boosted protease inhibitor. Management of these comorbid conditions must be prioritised in this group. If baseline screening eGFR is < 50 mL/min/1.73 m², abacavir (the preferred option), and dose-adjusted TDF (useful if concomitant hepatitis B), zidovudine or stavudine (d4T) remain alternatives to full-dose TDF. If there is a rapid decline in kidney function (eGFR drops by more than 25% and decreases to < 50 mL/min/1.73 m² from of baseline function), or there is new onset or worsening of proteinuria or albuminuria, clinicians should review ART and other potentially nephrotoxic medications and comorbidity and conduct further testing if indicated. If kidney function does not improve after addressing reversible causes of renal failure, then referral to a nephrologist is appropriate. In the case of severe CKD, timeous referral for planning for renal replacement therapy is recommended. Tenofovir alafenamide, a prodrug of tenofovir, appears to have less renal toxicity and is likely to replace TDF in future.

Long-term kidney function, proteinuria, and associated risks among HIV-infected and uninfected men

BACKGROUND

Factors affecting kidney function and proteinuria among HIV-positive (HIV+) and HIV-negative (HIV-) persons need better characterization.

METHODS

We evaluated estimated glomerular filtration rate (eGFR, ml/min per 1.73 m) changes, proteinuria prevalence (a urine protein-to-creatinine ratio of ≥0.2 at two consecutive visits) and associated factors among HIV+ and HIV- men.

RESULTS

There were 917 HIV+ men receiving HAART, 159 HIV+ men not receiving HAART, and 1305 HIV- men seen from October 2003 to September 2014. Median annual eGFR change was -0.5, -0.8% for HIV+ and -0.3% for HIV- men (P < 0.001). Factors significantly (P < 0.05) associated with more than 3% annual eGFR decline were HAART receipt (but no specific antiretroviral drug), age more than 50, hypertension, diabetes, current smoking. Proteinuria existed in 14.9% of visit-pairs among HAART recipients, 5.8% among non-HAART recipients, and 1.9% among HIV- men, and was associated with subsequent annual more than 3% eGFR decline (odds ratio 1.80, P < 0.001). Proteinuria-associated factors also included HAART use (vs. HIV-), age at least 50 (vs. <40), diabetes, hypertension, current smoking, hepatitis C virus-infection (all P < 0.05) and, among HIV+ men, lower CD4 cell count, didanosine, saquinavir, or nelfinavir use (all P < 0.05). After adjusting for proteinuria, among HAART users, having a detectable HIV RNA, cumulative use of tenofovir disoproxil fumarate, emtricitabine, ritonavir, atazanavir, any protease inhibitor, or fluconazole were associated with more than 3% annual eGFR decline.

CONCLUSION

Longitudinal kidney function decline was associated with HAART use but no individual antiretroviral drug, and traditional kidney disease risks. Proteinuria was nearly seven times more common in HAART-treated men than HIV- men, reflected recent eGFR decline and predicted subsequent eGFR decline.

Incidence and predictors of tenofovir disoproxil fumarate-induced renal impairment in HIV infected Nigerian patients

Introduction

The use of tenofovir disoproxil fumarate (TDF) in the treatment of HIV infection has been associated with renal dysfunction. In Nigeria, data on the incidence and risk factors of TDF nephrotoxicity is sparse. We determined the cumulative incidence of and risk factors for TDF-induced renal impairment in HIV-infected individuals accessing care at the antiretroviral therapy (ART) clinic of Jos University Teaching Hospital, Nigeria.

Methods

This retrospective cohort analysis included patients aged ≥16 years that initiated ART between January 2008 and December 2011. Renal impairment, defined as glomerular filtration rate GFR <60 mL/min/1.73 sqm using the Modification of Diet in Renal Disease (MDRD) equation was assessed at baseline and at 48 weeks on ART. Logistic regression was performed to determine factors associated with incident renal impairment.

Results

The mean age was 39±9 years, and 67.1% were female. The cumulative incidence of renal impairment among the TDF-exposed and TDF-unexposed groups was 4.6% and 2.3% respectively (p<0.001). TDF exposure was significantly associated with renal impairment [OR=2.0, 95%CI=(1.48-2.89), p<0.001] in bivariate analysis. In multivariate analysis, older age (aOR=1.06, 95%CI=(1.05-1.08), p<0.001), TDF exposure [aOR=1.85, 95%CI=(1.31-2.60), p<0.001] and co-morbidities [aOR=2.71, 95%CI=(1.72-4.25), p<0.001] were significantly associated with renal impairment.

Conclusion

TDF exposure, aging and comorbidities were predictors of renal toxicity among HIV positive patients. Regular monitoring of renal function in such high-risk individuals is recommended.

Prevalence and risk factors of mild chronic renal failure in HIV-infected patients: influence of female gender and antiretroviral therapy

Background

In people living with HIV, much is known about chronic kidney disease, defined as a glomerular filtration rate under 60 mL/min. However, there is scarce data about prevalence and risk factors for milder impairment (60–89 mL/min).

Objective

The present study aims to assess the influence of sex, antiretroviral therapy, and classical risk factors on the occurrence of mild decreased renal function in a large Spanish cohort of HIV-infected patients.

Methods

Cross-sectional, single center study, including all adult HIV-1-infected patients under antiretroviral treatment with at least two serum creatinine measures during 2014, describing the occurrence of and the risk factors for mildly decreased renal function (eGFR by CKD-EPI creatinine equation of 60–89 mL/min).

Results

Among the 4337 patients included, the prevalence rate of mildly reduced renal function was 25%. Independent risk factors for this outcome were age older than 50 years (OR 3.03, 95% CI 2.58–3.55), female sex (OR 1.23, 95% CI 1.02–1.48), baseline hypertension (OR 1.57, 95% CI 1.25–1.97) or dyslipidemia (OR 1.48, 95% CI 1.17–1.87), virologic suppression (OR 1.88, 95% CI 1.39–2.53), and exposure to tenofovir disoproxil-fumarate (OR 1.67, 95% CI 1.33–2.08) or ritonavir-boosted protease-inhibitors (OR 1.19, 95% CI 1.03–1.39).

Conclusions

Females and patients over 50 seem to be more vulnerable to renal impairment. Potentially modifiable risk factors and exposure to tenofovir disoproxil-fumarate or ritonavir-boosted protease-inhibitors are present even in earlier stages of chronic kidney dysfunction. It remains to be determined whether early interventions including antiretroviral therapy changes (tenofovir alafenamide, cobicistat) or improving comorbidities management will improve the course of chronic kidney disease.

A Review of Long-Term Toxicity of Antiretroviral Treatment Regimens and Implications for an Aging Population

Human immunodeficiency virus (HIV) is a chronic infectious disease currently requiring lifelong antiretroviral therapy (ART). People living with HIV (PLWH) face an increased risk of comorbidities associated with aging, chronic HIV, and the toxicity arising from long-term ART. A literature review was conducted to identify the most recent evidence documenting toxicities associated with long-term ART, particularly among aging PLWH. In general, PLWH are at a greater risk of developing fractures, osteoporosis, renal and metabolic disorders, central nervous system disorders, cardiovascular disease, and liver disease. There remains limited evidence describing the economic burden of long-term ART. Overall, an aging HIV population treated with long-term ART presents a scenario in which the clinical, humanistic, and economic burden for healthcare systems will demand thoughtful policy solutions that preserve access to treatment. Newer treatment regimens with fewer drugs may mitigate some of the cumulative toxicity burden of long-term ART.

Funding: ViiV Healthcare.

Renal health after long-term exposure to tenofovir disoproxil fumarate (TDF) in HIV/HBV positive adults in Ghana

OBJECTIVES

The study assessed markers of renal health in HIV/HBV co-infected patients receiving TDF-containing antiretroviral therapy in Ghana.

METHODS

Urinary protein-to-creatinine ratio (uPCR) and albumin-to-protein ratio (uAPR) were measured cross-sectionally after a median of four years of TDF. At this time, alongside extensive laboratory testing, patients underwent evaluation of liver stiffness and blood pressure. The estimated glomerular filtration rate (eGFR) was measured longitudinally before and during TDF therapy.

RESULTS

Among 101 participants (66% women, median age 44 years, median CD4 count 572 cells/mm³) 21% and 17% had detectable HIV-1 RNA and HBV DNA, respectively. Overall 35% showed hypertension, 6% diabetes, 7% liver stiffness indicative of cirrhosis, and 18% urinary excretion of Schistosoma antigen. Tubular proteinuria occurred in 16% of patients and was independently predicted by female gender and hypertension. The eGFR declined by median 1.8 ml/min/year during TDF exposure (IQR -4.4, -0.0); more pronounced declines (≥ 5 ml/min/year) occurred in 22% of patients and were associated with receiving ritonavir-boosted lopinavir rather than efavirenz. HBV DNA, HBeAg, transaminases, and liver stiffness were not predictive of renal function abnormalities.

CONCLUSIONS

The findings mandate improved diagnosis and management of hypertension and suggest targeted laboratory monitoring of patients receiving TDF alongside a booster in sub-Saharan Africa.

Relationship between combination antiretroviral therapy regimens and diabetes mellitus-related comorbidities among HIV patients in Gaborone Botswana

BACKGROUND

Combination antiretroviral therapy (cARTs) regiments are known to prolong the recipients' life even though they are risk factors for diabetes mellitus-related comorbidities (DRCs). We sought to: (i) examine cART relationship with DRCs among patients attending HIV clinics in Gaborone, Botswana (which cART regimens are associated with shorter/longer time to the event), (ii) characterize patients' underlying biomedical and demographic risk factors of DRC and identify the most important, (iii) investigate survival of patients on different cART regimens in the presence of these risk factors.

METHODS

Data from two major HIV clinics in Botswana were reviewed. Relationships between different cART regimens and DRCs were investigated among 531 recipients. Recipients' DRC risk factors were identified. Cox regression model was run. Unadjusted and adjusted hazard ratios were computed, and hazard and survival functions for different cART regimens were plotted.

RESULTS

Major findings were: patients on second- and third-line cART were less likely to develop DRCs earlier than those on first-line cART. Patients with CD4 count ≤ 200 cells/mm3 at cART initiation were more likely to develop DRCs earlier than those who had CD4 count > 200 cells/mm3. Overweight patients at cART initiation had a higher risk of developing DRCs earlier than those who had normal body mass index. Males had a lower risk of developing DRCs earlier than females.

CONCLUSION

The risk of new onset of DRC among cART recipients is a function of the type of cART regimen, duration of exposure and patients' underlying biomedical and demographic DRC risk factors. The study has provided a survival model highlighting DRCs' significant prognostic factors to guide clinical care, policy and management of recipients of cARTs. Further studies in the same direction will likely improve the survival to the development of DRC of every cART recipient in this community.

Prevalence and Evolution of Renal Impairment in People Living With HIV in Rural Tanzania

Background

We assessed the prevalence, incidence, and predictors of renal impairment among people living with HIV (PLWHIV) in rural Tanzania.

Methods

In a cohort of PLWHIV aged ≥15 years enrolled from January 2013 to June 2016, we assessed the association between renal impairment (estimated glomerural filtration rate < 90 mL/min/1.73 m²) at enrollment and during follow-up with demographic and clinical characteristcis using logistic regression and Cox proportional hazards models.

Results

Of 1093 PLWHIV, 172 (15.7%) had renal impairment at enrollment. Of 921 patients with normal renal function at baseline, 117 (12.7%) developed renal impairment during a median follow-up (interquartile range) of 6.2 (0.4–14.7) months. The incidence of renal impairment was 110 cases per 1000 person-years (95% confidence interval [CI], 92–132). At enrollment, logistic regression identified older age (adjusted odds ratio [aOR], 1.79; 95% CI, 1.52–2.11), hypertension (aOR, 1.84; 95% CI, 1.08–3.15), CD4 count <200 cells/mm³ (aOR, 1.80; 95% CI, 1.23–2.65), and World Health Organization (WHO) stage III/IV (aOR, 3.00; 95% CI, 1.96–4.58) as risk factors for renal impairment. Cox regression model confirmed older age (adjusted hazard ratio [aHR], 1.85; 95% CI, 1.56–2.20) and CD4 count <200 cells/mm³ (aHR, 2.05; 95% CI, 1.36–3.09) to be associated with the development of renal impairment.

Conclusions

Our study found a low prevalence of renal impairment among PLWHIV despite high usage of tenofovir and its association with age, hypertension, low CD4 count, and advanced WHO stage. These important and reassuring safety data stress the significance of noncommunicable disease surveillance in aging HIV populations in sub-Saharan Africa.

A LC/MS/MS method for determination of tenofovir in human plasma and its application to toxicity monitoring

Tenofovir disoproxil fumarate is a pro-drug of the active metabolite tenofovir widely used against the HIV1, HIV2, and Hepatitis B virus. Several studies have been conducted and found kidney injury associated with tenofovir exposure. High tenofovir plasma concentration correlated with kidney injury in tenofovir-exposed patients. The present study developed and validated a simple and cost-effective LC/MS/MS method to determine tenofovir level in human plasma. A small plasma volume of 80 μl is utilized for the sample preparation. The samples were separated by Luna C18 (100 mm × 2.0 mm, 3 μm) using gradient elution with a mobile phase consisting of water (containing 0.1% formic acid) and acetonitrile (90:10, v/v). The detection was achieved through multiple reaction monitoring using positive ionization mode on the triple quadrupole mass spectrometer with a run time of 10 min. The monitoring transitions were set at m/z 288.0 → 176.1 and 136.1 for tenofovir and m/z 226.1 → 152.0 for acyclovir (as the internal standard). This standard curve was linear from 10 to 640 ng/ml, with the lower limit of quantification of 10 ng/ml. The inter- and intra-day precision results were less than 12.3% and their accuracies were within the acceptable range of 84.9-113.1%. The validated method was successfully applied to the study of tenofovir induced kidney injury in HIV-1 infected patients taking 300 mg once daily for more than 4 weeks.

Tenofovir disoproxil fumarate co-administered with lopinavir/ritonavir is strongly associated with tubular damage and chronic kidney disease

BACKGROUD

With expanding antiretroviral therapy (ART) in a resource-limited setting, the use of second line ART with ritonavir boosted lopinavir (LPV/r) is increasing. However, little is known regarding the renal safety of tenofovir (TDF) co-administered with LPV/r.

METHODS

In total 1382 HIV-infected patients were enrolled and data were recorded twice (October 2014 and 2015) in Vietnam. Tubular dysfunction (TD) was defined as urinary beta 2 microglobulin (β2MG) > 1000 μg/L at both timepoints or increase in β2MG by > 2000 μg/L. Chronic kidney disease (CKD) was defined as creatinine clearance ≤60 ml/min or urinary protein/creatinine ratio ≥ 0.15 g/gCre at both timepoints.

RESULTS

The patients'mean weight and age were 55.9 kg and 38.4 years, respectively, and 41.5% were female. Additionally, 98.2% were on ART, 76.3% were on TDF (mean exposure duration was 35.4 months), and 22.4% had never TDF exposure. TD and CKD were diagnosed in 13% and 8.3% of all patients, respectively. In multivariate analyses, age (OR = 1.057; 95%CI, 1.034-1.081), being female (OR = 0.377; 95%CI, 0.221-0.645), HBsAg positive (OR = 1.812; 95%CI, 1.134-2.894), HCVAb positive (OR = 1.703; 95%CI, 1.100-2.635), TDF exposure (OR = 9.226; 95%CI, 2.847-29.901) and LPV/r exposure (OR = 5.548; 95%CI, 3.313-9.293) were significantly associated with TD. Moreover, age (OR = 1.093; 95%CI, 1.068-1.119), being female (OR = 0.510; 95%CI, 0.295-0.880), weight (OR = 0.909; 95%CI, 0.879-0.939), hypertension (OR = 3.027; 95%CI, 1.714-5.347), TDF exposure (OR = 1.963; 95%CI, 1.027-3.7 53) and LPV/r exposure (OR = 3.122; 95%CI, 1.710-5.699) were significantly associated with CKD.

CONCLUSIONS

TDF and LPV/r exposure were strongly associated with TD and CKD, in addition to their known risks. Therefore, attention to renal safety for patients on second line ART is necessary.

Potential kidney toxicity from the antiviral drug tenofovir: new indications, new formulations, and a new prodrug

PURPOSE OF REVIEW

The antiviral agent tenofovir is highly effective for the treatment of HIV and hepatitis B virus infections, and the older prodrug tenofovir disoproxil fumarate (TDF) is also a component of daily preexposure prophylaxis (PrEP) to reduce the risk of HIV infection in high-risk populations. Although TDF is well tolerated, the potential for kidney and bone toxicity has important implications for public health given the large number of individuals exposed to TDF worldwide. This review summarizes the recent literature on kidney and bone health in individuals treated with TDF and the newer prodrug tenofovir alafenamide (TAF).

RECENT FINDINGS

Risk factors for TDF toxicity appear to be similar in patients treated for HIV or hepatitis B virus and in HIV-uninfected PrEP users, although drug-drug interactions are a more important concern in HIV-positive individuals. The risk of toxicity appears to be lower with TAF, but further studies are needed to confirm the safety of long-term use and to evaluate the efficacy of TAF-based PrEP.

SUMMARY

Nephrologists should be aware of the potential kidney and bone toxicity of TDF, as well as unique situations in which the newer prodrug TAF may contribute to kidney injury.

Kidney disease in the setting of HIV infection: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

HIV-positive individuals are at increased risk for kidney disease, including HIV-associated nephropathy, noncollapsing focal segmental glomerulosclerosis, immune-complex kidney disease, and comorbid kidney disease, as well as kidney injury resulting from prolonged exposure to antiretroviral therapy or from opportunistic infections. Clinical guidelines for kidney disease prevention and treatment in HIV-positive individuals are largely extrapolated from studies in the general population, and do not fully incorporate existing knowledge of the unique HIV-related pathways and genetic factors that contribute to the risk of kidney disease in this population. We convened an international panel of experts in nephrology, renal pathology, and infectious diseases to define the pathology of kidney disease in the setting of HIV infection; describe the role of genetics in the natural history, diagnosis, and treatment of kidney disease in HIV-positive individuals; characterize the renal risk-benefit of antiretroviral therapy for HIV treatment and prevention; and define best practices for the prevention and management of kidney disease in HIV-positive individuals.

Changes in Kidney Function Associated With Daily Tenofovir Disoproxil Fumarate/Emtricitabine for HIV Preexposure Prophylaxis Use in the United States Demonstration Project

BACKGROUND

HIV preexposure prophylaxis (PrEP) using daily oral tenofovir-disoproxil-fumarate/emtricitabine (TDF/FTC) is effective for preventing HIV acquisition, but concerns remain about its potential kidney toxicity. This study examined kidney function in individuals using PrEP in real-world clinical settings.

SETTING

Demonstration project in 2 sexually transmitted infection clinics and a community health center.

METHODS

We evaluated kidney function among men who have sex with men and transgender women taking tenofovir-disoproxil-fumarate/emtricitabine PrEP for up to 48 weeks. Serum creatinine and urine dipstick for protein were obtained at 12-week intervals. Kidney function was estimated using creatinine clearance (CrCl) (Cockcroft-Gault) and estimated glomerular filtration rate (eGFR) (CKD-EPI).

RESULTS

From October 2012 to January 2014, we enrolled 557 participants (median age 33). Mean creatinine increased from baseline to week 12 by 0.03 mg/dL (4.6%) (P < 0.0001); mean CrCl decreased by 4.8 mL/min (3.0%) (P < 0.0001). These changes remained stable through week 48 (P = 0.81, P = 0.71 respectively). There were 75/478 (15.7%) participants who developed worsening proteinuria at week 12 compared with baseline (P < 0.0001), and this percent remained stable through week 48 (P = 0.73). Twenty-five participants (5.1%) developed new-onset eGFR <70 mL/min/1.73 m; independent predictors of this outcome were age ≥40 years (OR 3.79, 95% CI: 1.43 to 10.03) and baseline eGFR <90 mL/min/1.73 m (OR 9.59, 3.69-24.94).

CONCLUSIONS

In a demonstration setting, daily tenofovir-disoproxil-fumarate/emtricitabine PrEP leads to reduced CrCl and eGFR; however, these eGFR changes are based on very small changes in serum creatinine and seem to be nonprogressive after the first 12 weeks. Future studies are needed to understand the prognostic significance of these small changes.

Cumulative exposure of TDF is associated with kidney tubulopathy whether it is currently used or discontinued

OBJECTIVE

Tenofovir disoproxil fumarate (TDF) increases the risk of kidney tubular dysfunction (KTD). This study was conducted to elucidate whether KTD persists after discontinuation of TDF.

DESIGN

A prospective cross-sectional study which enrolled 941 HIV-1-infected patients.

METHODS

KTD was predefined as the presence of at least two abnormalities among the five tubular markers (fractional excretion of phosphate, fractional excretion of uric acid, β2 microglobulinuria, N-acetyl-β-D-glucosaminidase, nondiabetic glycosuria). Logistic regression model was used to examine the association between KTD and cumulative TDF use, as well as current status of TDF use.

RESULTS

In total, 94% of study patients were men (median age 45, estimated glomerular filtration rate 75 ml/min per 1.73 m, CD4 575 cells/μl. About 98% were on antiretroviral therapy. In total, 64% of the patients ever used TDF and 39% currently used TDF. Twenty-nine percent used TDF for more than 5 years. KTD was diagnosed in 116 (12%) patients. In multivariate model, more than 5 years of TDF exposure and current TDF use [odds ratio (OR) 4.2, 95% confidence interval (CI) 2.37-7.56], more than 5 years and past TDF use (OR 2.4, 95% CI 1.09-5.33), less than 5 years and current TDF (OR 2.4, 95% CI 1.24-4.85), and less than 5 years and past TDF (OR 2.4, 95% CI 1.22-4.64) were all significantly associated with KTD, with never TDF use as reference. The results were the same using 4 and 3 years of exposure as the cutoff. However, with 2 years exposure, both less than 2 years and current TDF (OR 2.3, 95% CI 0.84-6.20) and less than 2 years and past TDF (OR 1.9, 95% CI 0.73-4.93) were not associated with KTD, whereas both more than 2 years and current TDF and more than 2 years and past TDF were associated.

CONCLUSION

The association between cumulative TDF use and KTD was strong and robust. The results of the study suggested that TDF-related KTD might persist after discontinuation of TDF if patients used TDF for more than 2 years.

Decreased expression of megalin and cubilin and altered mitochondrial activity in tenofovir nephrotoxicity

Tenofovir disoproxil fumarate (TDF) is a commonly used antiretroviral drug for HIV, rarely causing Fanconi syndrome and acute kidney injury. We retrospectively analyzed the clinico pathological presentation of 20 cases of tenofovir-induced tubulopathy, and investigated the renal expression of the megalin and cubilin proteins, as well as the mitochondrial respiratory chain activity. Estimated glomerular filtration rate (eGFR) before TDF exposure was 92 ml/min/1.73m², decreasing to 27.5 ml/min/1.73m² at the time of biopsy, with 30% of patients requiring renal replacement therapy. Proximal tubular expression of megalin and cubilin was altered in 19 and 18 cases, respectively, whereas it was preserved in patients exposed to TDF without proximal tubular dysfunction and in HIV-negative patients with acute tubular necrosis. Loss of megalin/cubilin was correlated with low eGFR and high urine retinol binding protein at the time of biopsy, low eGFR at last follow-up, and was more severe in patients with multifactorial toxicity. Patients with additional nephrotoxic conditions promoting tenofovir accumulation showed a lower eGFR at presentation and at last follow-up, and more severe lesions of acute tubular necrosis, than those with isolated tenofovir toxicity. Altered mitochondrial COX activity in proximal tubules was observed and may be an early cellular alteration in tenofovir nephrotoxicity. In conclusion, altered megalin/cubilin expression represents a distinctive feature in tenofovir-induced tubulopathy, and its severity is correlated with urine retinol binding protein loss and is associated with a poor renal prognosis. Concomitant exposure to other nephrotoxic conditions severely impacts the renal presentation and outcome.

Precision medicine for HIV: where are we?

To date, antiretroviral therapy is highly effective in HIV-affected patients, but the individualization of such a life-long therapy may be advised. This review briefly summarizes the main factors involved in the potential personalization of antiretroviral treatment. Relevant articles in English were identified by PubMed and recent congresses’ abstracts. Foremost influences concerning pharmacodynamics, therapeutic drug monitoring, pharmacogenetics, comorbidities, immune recovery and viral characteristics affecting the healthcare of HIV-positive patients are listed here. Furthermore, pharmacoeconomic aspects are mentioned. Applying pharmacokinetic and pharmacogenetic knowledge may be informative and guide the better choice of treatment in order to achieve long-term efficacy and avoid adverse events. Randomized investigations of the clinical relevance of tailored antiretroviral regimens are needed in order to obtain a better management of HIV/AIDS-affected patients.

Abacavir usage patterns and hypersensitivity reactions in the EuroSIDA cohort

OBJECTIVES

Five to eight per cent of HIV-positive individuals initiating abacavir (ABC) experience potentially fatal hypersensitivity reactions (HSRs). We sought to describe the proportion of individuals initiating ABC and to describe the incidence and factors associated with HSR among those prescribed ABC.

METHODS

We calculated the proportion of EuroSIDA individuals receiving ABC-based combination antiretroviral therapy (cART) among those receiving cART after 1 January 2009. Poisson regression was used to identify demographic, and current clinical and laboratory factors associated with ABC utilization and discontinuation.

RESULTS

Between 2009 and 2016, of 10 076 individuals receiving cART, 3472 (34%) had ever received ABC-based cART. Temporal trends of ABC utilization were also heterogeneous, with 28% using ABC in 2009, dropping to 26% in 2010 and increasing to 31% in 2016, and varied across regions and over time. Poisson models showed lower ABC utilization in older individuals, and in those with higher CD4 cell counts, higher cART lines, and prior AIDS. Higher ABC utilization was associated with higher HIV RNA and poor renal function, and was more common in Central-East and Eastern Europe and lowest during 2014. During 779 person-years of follow-up (PYFU) in 2139 individuals starting ABC after 1 January 2009, 113 discontinued ABC within 6 weeks of initiation for any reason [incidence rate (IR) 14.5 (95% confidence interval (CI) 12.1, 17.5) per 100 PYFU], 13 because of reported HSR [IR 0.3 (95% CI 0.1, 1.0) per 100 PYFU] and 35 because of reported HSR/any toxicity [IR 4.5 (95% CI 3.2, 6.3) per 100 PYFU]. There were no factors significantly associated with ABC discontinuation because of reported HSR/any toxicity.

CONCLUSIONS

ABC remains commonly used across Europe and the incidence of discontinuation because of reported HSR was low in our study population.

Effect of Cobicistat on Tenofovir Disoproxil Fumarate (TDF): What Is True for TAF May Also Be True for TDF

BACKGROUND

The dose of tenofovir alafenamide is reduced from 25 to 10 mg daily when given with boosting agents. However, such dose reduction has never been adopted for tenofovir disoproxil fumarate (TDF). In this study, we aim to quantify the effect of cobicistat (COBI) both on tenofovir concentrations and TDF durability in real life setting.

METHODS

HIV-positive patients receiving TDF-containing antiretroviral therapies with at least 1 assessment of tenofovir plasma trough concentrations were included in the study. Univariate and multivariate regression analyses were performed considering tenofovir concentration as the dependent variable and clinical characteristics as independent covariates. Subsequently, survival and Cox analyses were performed considering as the primary outcome TDF discontinuation for any reasons.

RESULTS

Patients were given TDF with protease inhibitors/ritonavir (n = 212), non-nucleoside reverse transcriptase inhibitors (n = 176), integrase inhibitors (dolutegravir or raltegravir, n = 46), or with elvitegravir/COBI (ELV/COBI) (n = 76). By multivariate analysis, concomitant antiretroviral therapies resulted significantly associated with tenofovir levels, with the highest drug concentrations measured in patients given ELV/COBI. By survival analysis, we found that patients given TDF with ELV/COBI had the lowest rate of drug durability. Overall, these patients had a 2.3-fold increased risk to experience TDF discontinuation.

CONCLUSIONS

Coadministration with COBI resulted in significantly higher tenofovir concentrations and higher TDF discontinuation compared with other antiretroviral regimens. Accordingly, the possibility that the lack of proper dose adjustment for TDF when given with COBI might have biased the safety comparisons with tenofovir alafenamide during registrative trials cannot be ruled out.

HIV treatment simplification to elvitegravir/cobicistat/emtricitabine/tenofovir disproxil fumarate (E/C/F/TDF) plus darunavir: a pharmacokinetic study

BACKGROUND

As a simplification strategy for treatment-experienced HIV-infected patients who have achieved virologic suppression on a multi-drug, multi-class antiretroviral regimen, the aim of this study was to evaluate the safety, efficacy, and pharmacokinetics of once-daily elvitegravir/cobicistat/emtricitabine/tenofovir disproxil fumarate (E/C/F/TDF) with darunavir.

METHODS

A single arm, open-label 48-week study was conducted of regimen simplification to E/C/F/TDF plus darunavir 800 mg daily from stable therapy including two nucleoside/nucleotide reverse transcriptase inhibitors, a ritonavir-boosted protease inhibitor, and an integrase inhibitor. Participants had plasma HIV viral load consistently < 200 copies/mL for ≥ 6 months, estimated glomerular filtration rate (eGFR) ≥ 60 mL/min, and no genotypic resistance to major components of the study regimen. Plasma viral load was measured at weeks 2 and 4, then every 4 weeks throughout the study. Safety laboratory assessments were conducted at baseline and at weeks 12, 24, 36, and 48. Antiretroviral drug concentrations were measured at baseline and once ≥ 2 weeks after the regimen change.

RESULTS

Ten HIV-infected adults (8 male and 2 female; median age 50.5 years) were enrolled. All maintained virologic suppression on the new regimen for 48 weeks. One subject experienced a decrease in eGFR from 62 mL/min at baseline to 52 mL/min at week 12; study medications were continued and his eGFR remained stable (50-59 mL/min) thereafter. No subjects discontinued study medications for renal function changes or other adverse events. Darunavir trough concentration were lower on the new regimen than on darunavir/ritonavir 800/100 mg (n = 5; p < 0.05).

CONCLUSIONS

Despite low darunavir trough concentrations, treatment simplification to a two-pill, once-daily regimen of E/C/F/TDF plus darunavir was safe and effective for 48 weeks among 10 selected treatment-experienced HIV-infected patients. Trial registration The study protocol was registered with ClinicalTrials.gov (NCT02199613) on July 22, 2014.

Kidney Disease in HIV: Moving beyond HIV-Associated Nephropathy

In developed countries, remarkable advances in antiretroviral therapy have transformed HIV infection into a chronic condition. As a result, HIV-associated nephropathy, the classic HIV-driven kidney lesion among individuals of African descent, has largely disappeared in these regions. However, HIV-positive blacks continue to have much higher rates of ESRD than HIV-positive whites, which could be attributed to the APOL1 renal risk variants. Additionally, HIV-positive individuals face adverse consequences beyond HIV itself, including traditional risk factors for CKD and nephrotoxic effects of antiretroviral therapy. Concerns for nephrotoxicity also extend to HIV-negative individuals using tenofovir disoproxil fumarate-based pre-exposure prophylaxis for the prevention of HIV infection. Therefore, CKD remains an important comorbid condition in the HIV-positive population and an emerging concern among HIV-negative persons receiving pre-exposure prophylaxis. With the improved longevity of HIV-positive individuals, a kidney transplant has become a viable option for many who have progressed to ESRD. Herein, we review the growing knowledge regarding the APOL1 renal risk variants in the context of HIV infection, antiretroviral therapy-related nephrotoxicity, and developments in kidney transplantation among HIV-positive individuals.

Higher Prevalence and Faster Progression of Chronic Kidney Disease in Human Immunodeficiency Virus-Infected Middle-Aged Individuals Compared With Human Immunodeficiency Virus-Uninfected Controls

Background

Human immunodeficiency virus (HIV)-infected individuals are at increased risk of chronic kidney disease (CKD). Human immunodeficiency virus infection, traditional CKD risk factors, and combination antiretroviral therapy (cART) may all contribute.

Methods

We compared prevalence of renal impairment (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73m2), albuminuria (albumin/creatinine ratio ≥3 mg/mmol), and proximal renal tubular dysfunction (retinol-binding protein/creatinine ratio >2.93μg/mmol and/or fractional phosphate excretion >20% with plasma phosphate <0.8 mmol/L) in 596 HIV-infected and 544 HIV-uninfected AGEhIV Cohort Study participants. We also assessed whether being HIV-infected on cART, with follow-up censored when cART regimen was modified, was associated with greater eGFR decline or worsening albuminuria (increase ≥10%/year with change in albuminuria category).

Results

Human immunodeficiency virus infection was independently associated with renal impairment (adjusted odds ratio [aOR] = 2.1; 95% confidence interval [CI] = 1.0-4.4), albuminuria (aOR = 5.8; 95% CI = 3.7-9.0), and proximal renal tubular dysfunction (aOR = 7.0; 95% CI = 4.9-10.2]). Among 377 HIV-infected and 479 HIV-uninfected individuals (median follow-up = 3.9/4.1 years, respectively) included in longitudinal analyses, being HIV-infected and remaining on unmodified cART was independently associated with greater eGFR decline (-0.56; 95% CI = -0.87 to -0.24 mL/min/1.73m2/year) and worsening albuminuria (aOR = 2.3; 95% CI = 1.3-4.0).

Conclusions

In these middle-aged individuals, HIV infection was independently associated with renal impairment, albuminuria, and proximal renal tubular dysfunction. Human immunodeficiency virus-infected individuals on cART (predominantly containing tenofovir disoproxil fumarate) were also more likely to experience eGFR decline and worsening albuminuria compared with HIV-uninfected individuals.

A review of drug-drug interactions in older HIV-infected patients

INTRODUCTION

The number of older HIV-infected people is growing due to increasing life expectancies resulting from the use of antiretroviral therapy (ART). Both HIV and aging increase the risk of other comorbidities, such as cardiovascular disease, osteoporosis, and some malignancies, leading to greater challenges in managing HIV with other conditions. This results in complex medication regimens with the potential for significant drug-drug interactions and increased morbidity and mortality. Area covered: We review the metabolic pathways of ART and other medications used to treat medical co-morbidities, highlight potential areas of concern for drug-drug interactions, and where feasible, suggest alternative approaches for treating these conditions as suggested from national guidelines or articles published in the English language. Expert commentary: There is limited evidence-based data on ART drug interactions, pharmacokinetics and pharmacodynamics in the older HIV-infected population. Choosing and maintaining effective ART regimens for older adults requires consideration of side effect profile, individual comorbidities, interactions with concurrent prescriptions and non-prescription medications and supplements, dietary patterns with respect to dosing, pill burden and ease of dosing, cost and affordability, patient preferences, social situation, and ART resistance history. Practitioners must remain vigilant for potential drug interactions and intervene when there is a potential for harm.

Tenofovir alafenamide nephrotoxicity in an HIV-positive patient: A case report

RATIONALE

Tenofovir alafenamide (TAF) is novel prodrug of Tenofovir, a nucleotide reverse transcriptase inhibitor. TAF is less nephrotoxic than its predecessor prodrug, tenofovir disoproxil fumarate (TDF). Tenofovir causes mitochondrial dysfunction and tubular injury when there is elevated accumulation in proximal tubule cells. TAF's unique pharmacokinetic profile enables provision of lower required doses for antiviral efficacy. Lower concentrations reach renal tubules minimizing intracellular accumulation and mitochondrial damage. TAF has not been associated with the histologic markers of tenofovir-associated nephrotoxicity that are seen with TDF, such as dysmorphic mitochondria in proximal tubule cells. Here, we report a patient with dysmorphic mitochondria on kidney biopsy after initiating therapy with TAF.

LESSONS

This case suggests that at risk individuals may experience tubular mitochondrial injury from lower concentrations of tenofovir with TAF.

Changes in Kidney Function and in the Rate of Tubular Dysfunction After Tenofovir Withdrawal or Continuation in HIV-Infected Patients

INTRODUCTION

Longitudinal data on the changes in kidney function and tubular abnormalities in case of tenofovir disoproxil fumarate (TDF) withdrawal or continuation are scarce.

METHODS

Prospective study of 228 patients receiving TDF, with 3 sequential determinations of serum creatinine, estimated glomerular filtration rate (eGFR), phosphatemia, and different urinary parameters (protein, albumin, phosphaturia, uricosuria, and glycosuria). Changes were analyzed in patients who interrupted TDF as compared to those who continued the same regimen. Proximal renal tubular dysfunction (PRTD) was defined as ≥2 tubular abnormalities.

RESULTS

After a median follow-up of 59.5 months, 78 patients (34%) had PRTD, mainly proteinuria (40%) and phosphaturia (61%), and time on TDF explains the severity of tubular alterations and eGFR slopes. In 35 switching patients, there was a rapid and significant eGFR improvement (median +4.1 ml/min per 1.73 m; P = 0.02), leading to a 39%-83% reduction in the prevalence of tubular abnormalities and of PRTD in less than 1 year (66%-39%). In comparison, 193 patients continuing the same regimen for 21.2 months had a small but significant and progressive eGFR decrease (-2.9 mL·min·1.73 m; P < 0.01), and a progressive rise in the prevalence of phosphaturia, uricosuria, and glycosuria (+9%-56%). In linear mixed-effect model, subsequent eGFR impairment was associated with proteinuria and time on TDF, and eGFR improvement with TDF discontinuation.

CONCLUSIONS

Our data support the role of use and time on TDF in eGFR decline and tubular dysfunction. In contrast, TDF withdrawal is followed by a rapid and significant, although partial, recovery of eGFR and tubular abnormalities.