Association of tenofovir exposure with kidney disease risk in HIV infection

Impact of HIV-1 tropism on the emergence of non-AIDS events in HIV-infected patients receiving fully suppressive antiretroviral therapy

Objective:

The impact of HIV-1 tropism on the emergence of non-AIDS events was evaluated in a cohort of 116 antiretroviral therapy (ART) responder patients.

Methods:

The patients were followed for the emergence of hypertension, renal impairment, metabolic and bone disorders (defined as non-AIDS events) each 8 weeks at standard visits. A V3 plasma sequence genotype analysis was performed at the time of ART initiation and the geno2pheno algorithm with the results that defines the false-positive rate (FPR) was used to infer HIV tropism. The associations between the non-AIDS events and the FPR at baseline were evaluated using the χ² test for trend. A Cox-regression analysis using the counting process formulation of Andersen and Gill was performed to define whether the emergence of non-AIDS events was correlated to FPR.

Results:

The prevalence of at least one non-AIDS event resulted higher in patients with a FPR below 10% than in patients with a R5 virus (P = 0.033). Patients with a FPR below 5.0% most frequently developed non-AIDS events during ART (P = 0.01). A higher prevalence of patients with at least two AIDS events was found in the group of patients with a FPR below 5.0% with respect to the others (P < 0.001). At multivariate Cox-regression analysis, having an X4 virus and age were independently associated with a higher probability of non-AIDS event development.

Conclusion:

This study shows that an X4 virus, particularly a FPR less than 5%, is related to non-AIDS events development. Further studies are warranted to understand the mechanisms underlying this phenomenon.

Higher tenofovir exposure is associated with longitudinal declines in kidney function in women living with HIV

OBJECTIVE

Tenofovir disoproxil fumarate is a commonly used antiretroviral drug, but risk factors for tenofovir (TFV)-associated kidney disease are not fully understood. We used intensive pharmacokinetic studies in a cohort of HIV-infected women on TFV-based therapy to study the relationship between TFV exposure and subsequent kidney function.

DESIGN

This is a nested study within the Women's Interagency HIV Study, a multicenter, prospective cohort of HIV-infected women. Participants on TFV-based therapy underwent 24-h intensive pharmacokinetic sampling after witnessed dose. Kidney function was measured over the succeeding 7 years by serum creatinine [estimated glomerular filtration rate calculated by serum creatinine (eGFRcr)].

METHODS

Multivariable linear mixed models evaluated the relationship of baseline TFV area under the-time concentration curves (AUCs) with subsequent changes in kidney function. Covariates included age, diabetes, hypertension, race, BMI, ritonavir use, duration of TFV exposure, current CD4 cell count, and HIV viral load.

RESULTS

Of the 105 participants, persons within the highest baseline TFV AUC tertile had significantly lower eGFRcr compared with those in the lowest tertile (mean ± standard error: 80 ± 4.3 vs. 104 ± 2.5 ml/min per 1.73 m, P < 0.0001). By year 7, this difference widened (72 ± 4.9 vs. 105 ± 2.9, P < 0.0001). After multivariable adjustment, TFV AUC in the highest tertile remained associated with lower eGFRcr relative to values in the lowest tertile at both baseline (-15 ml/min per 1.73 m, P = 0.0047) and year 7 (-23 ml/min per 1.73 m, P = 0.0002).

CONCLUSION

Through intensive TFV pharmacokinetic sampling, we found a strong association between greater TFV exposure and subsequent decline in kidney function. Variations in TFV drug exposure may partially account for subsequent nephrotoxicity in persons infected with HIV.

Current state and limitations of daily oral therapy for treatment

PURPOSE OF REVIEW

We aim to review the strengths and weaknesses of current antiretroviral therapy (ART), and describe ongoing research to address limitations to current therapy.

RECENT FINDINGS

Current ART is highly effective and well tolerated. As a result of a decrease in medication side-effects and pill burden, and the known health effects of uncontrolled viremia, ART is now recommended at all CD4 cell counts in the USA. Novel medications are being developed to further decrease side-effects and offer alternative options for patients with multiclass resistance. New combination pills will further decrease pill burden.

SUMMARY

Current treatment for HIV is characterized by highly potent oral antiretroviral medications, which are well tolerated, resulting in outstanding rates of virologic suppression in patients who are adherent to therapy. Despite the marked improvement in therapeutic options, limitations to therapy still exist including reliance on daily adherence, long-term toxicity of medications, drug-drug interactions, long-term effects of HIV even in the setting of viral suppression, high lifetime cost of treatment, and limited options for some patients with multiclass resistance. Emerging alternative treatment strategies include nucleoside reverse transcriptase inhibitor-sparing or limiting regimens and long-acting injectable combination therapy.

Prevalence and distribution of non-AIDS causes of death among HIV-infected individuals receiving antiretroviral therapy: a systematic review and meta-analysis

The advent of antiretroviral therapy has significantly improved AIDS-related morbidity and mortality. Yet, among people living with HIV, deaths due to non-AIDS-defining illnesses have been on the rise. The objective of this study was to provide information about the global prevalence and distribution of non-AIDS causes of death in the last ten years among people living with HIV receiving antiretroviral therapy, by income levels of countries. We used broad search terms in Google Scholar, PubMed, and EMBASE to identify all studies that investigated the cause of death among people living with HIV receiving antiretroviral therapy, published after January 1, 2005. References were also identified from review articles and reference lists. Inclusion criteria were English language, the study’s end date was after 2005, all patients were HIV-positive, at least two-thirds of the patients were receiving antiretroviral therapy, at least one patient died of non-AIDS causes of death. Titles, abstracts, and articles were reviewed by at least two independent readers. Of 2951 titles identified in our original search, 151 articles were selected for further screening. We identified 19 studies meeting our full criteria, with patients from 55 different nations. Pooled non-AIDS causes of death prevalence estimates in high-income countries were 53.0% (95% confidence interval, 43.6–62.3), in developing countries 34.0% (95% confidence interval, 20.3–49.1), and in sub-Saharan countries 18.5% (95% confidence interval, 13.8–23.7). Statistically significant variation was noted within and between categories. Our findings show that a significant number of people living with HIV across the world die from cardiovascular disease, non-AIDS malignancies, and liver disease. There is a global need for further scrutiny in all regions to improve preventive measures and early detection according to distinct causes of death patterns.

Choice of antiretroviral drugs for continued treatment scale-up in a public health approach: what more do we need to know?

INTRODUCTION

There have been several important developments in antiretroviral treatment in the past two years. Randomized clinical trials have been conducted to evaluate a lower dose of efavirenz (400 mg once daily). Integrase inhibitors such as dolutegravir have been approved for first-line treatment. A new formulation of tenofovir (alafenamide) has been developed and has shown equivalent efficacy to tenofovir in randomized trials. Two-drug combination treatments have been evaluated in treatment-naïve and -experienced patients. The novel pharmacokinetic booster cobicistat has been compared to ritonavir in terms of pharmacokinetics, efficacy and safety. The objective of this commentary is to assess recent developments in antiretroviral drug treatment to determine whether new treatments should be included in new international guidelines.

DISCUSSION

The use of first-line treatment with tenofovir and efavirenz at the standard 600 mg once-daily dose should remain the first-choice standard of care treatment. Evidence supporting a switch to efavirenz 400 mg once daily or integrase inhibitors is sufficient to consider these drugs as alternative first-line options, but more data are needed on their use in pregnant women and people with TB co-infection. The use of new formulations of tenofovir is currently too preliminary to justify immediate adoption and scale-up across HIV programmes in low- and middle-income countries. The evidence supporting use of two-drug combinations is not considered strong enough to justify changed recommendations from use of standard triple drug combinations. Cobicistat does not offer significant safety advantages over ritonavir as a pharmacokinetic booster.

CONCLUSIONS

For continued scale-up of antiretroviral treatment in low- and middle-income countries, use of first-line triple combinations including efavirenz 600 mg once daily is supported by the largest evidence base. Additional studies are underway to evaluate new treatments in key populations, and these results may justify changes to these recommendations.

Targeted spontaneous reporting of suspected renal toxicity in patients undergoing highly active anti-retroviral therapy in two public health facilities in Uganda

Background

Although the national HIV control programme in Uganda has a well-established system for monitoring disease progression and treatment outcomes, monitoring of adverse drug reactions (ADRs) is inadequate. In order to address under-reporting of ADRs, the National Pharmacovigilance Centre, in collaboration with the HIV control programme, piloted a targeted spontaneous reporting (TSR) system as a complementary method to traditional spontaneous reporting.

Methods

From April 2012 to March 2014, all cases of suspected renal toxicity in 10,225 patients on tenofovir-based regimens were monitored in the regional pharmacovigilance centres of Masaka and Mbale. The identification of renal toxicity was performed using serum creatinine, urinalysis, and other signs and symptoms of kidney injury.

Results

There was one suspected renal toxicity reported for every 200 patients on a tenofovir-based regimen. Some of the serious reactions reported were death in two cases and bone demineralisation in five patients. Most of patients had been on treatment for 2 years. Those that had been on tenofovir for more than 4 years had raised serum creatinine levels, emphasising the importance of monitoring for the risk of renal damage for longer. We also found that the reporting rate of suspected ADRs for all medicines in the two sites increased almost fivefold during the implementation period.

Conclusion

Although the occurrence of suspected tenofovir renal toxicity of HIV patients is low, there is need to monitor those at risk so as to prevent irreversible kidney injury. TSR can complement spontaneous reporting for collecting safety data on particular drugs and increase ADR reporting rates.

Electronic supplementary material

The online version of this article (doi:10.1007/s40264-015-0277-9) contains supplementary material, which is available to authorized users.

Prevalence and significance of proximal renal tubular abnormalities in HIV-infected patients receiving tenofovir

OBJECTIVES

Patients receiving tenofovir, disoproxil, fumarate (TDF) had an increased prevalence of proximal renal tubular dysfunction (PRTD), but contributing factors and its clinical significance remain controversial.

DESIGN AND METHODS

Cross-sectional evaluation of different urinary parameters (proteinuria, albuminuria, phosphaturia, uricosuria, glycosuria) in 200 HIV-infected patients receiving TDF, 26 following TDF discontinuation, and 22 never treated with TDF, included in a prospective cohort study. PRTD was defined as two or more tubular abnormalities.

RESULTS

After a median of 65 months (interquartile range, 42.7-84.7), at least one tubular alteration was found in 72% of patients, mostly proteinuria (42, 50, and 14% in current, previous and never TDF use; P=0.02) and phosphaturia (46, 42, and 14%; respectively, P < 0.01). PRTD was found in 63 patients (32%) receiving TDF, ranging from 14 to 46% according to concomitant hepatitis C virus coinfection, diabetes mellitus or hypertension arterial, in contrast with six (23%) following TDF discontinuation, and zero cases in no TDF-treated patients. The use of TDF [odds ratio (OR) 13.2; 95% confidence interval (CI) 1.4-22.7; P = 0.01], cumulative time on combination antiretroviral therapy (OR 1.011; 95% CI 1.07-1.019 per month; P = 0.01), and baseline estimated glomerular filtration rate (eGFR, OR 0.97; 95% CI 0.94-0.99 per ml/min per 1.73 m higher; P = 0.04) were associated with PRTD. The number of tubular abnormalities was linearly associated with eGFR decline since TDF initiation (β-coefficient -0.15, P = 0.02), together with age (-0.18; P = 0.01), baseline eGFR (0.49, P = 0.01), diabetes mellitus (-0.19, P = 0.02), and time on TDF (-0.23; P = 0.01).

CONCLUSION

The use of TDF leads to an increased rate of tubular dysfunction, and modulated by age, baseline eGFR, and classical factors, is associated with kidney function decline.

Tenofovir monotherapy for hepatitis B after 1 year does not produce renal dysfunction, but is associated with hyperparathyroidism not related to vitamin D

INTRODUCTION

Viral hepatitis B (VHB) represents a major public health problem. Studies from HIV multidrug patients have associated the use of tenofovir disoproxil fumarate (TDF) with renal dysfunction and phosphate wasting.

OBJECTIVE

The aim of this study was to examine the effect of year-long TDF monotherapy on renal function in VHB patients.

PATIENTS AND METHODS

We evaluated adult patients diagnosed with VHB before treatment initiation (T0), and after 3 and 12 months (T3 and T12) of TDF initiation. Estimated glomerular filtration rate (eGFR) was estimated by serum cystatin C and creatinine. In addition, urinary electrolytes and tubular biomarkers (cystatin C, β2-microglobulin and neutrophil gelatinase-associated lipocalin) were analyzed, as well as parathyroid hormone (PTH) and 25(OH)vitamin D levels.

RESULTS

After 1 year, 32 patients completed the study, 22 (68.7%) men and 12 (37.5%) Whites, mean age 44.1±12.0 years. We found that serum electrolytes were similar at baseline and 3 or 12 months after initiation of TDF monotherapy. In addition, urinary fractional excretions of electrolytes as well as proteinuria, albuminuria, urinary β2-microglobulin, and urinary cystatin C showed no significant differences across the treatment timeline. There were also no statistical differences in the eGFR. There was a statistically significant increase in the PTH (Friedman's test, P=0.012), but the 25(OH)vitamin D levels were in the normal range in the beginning and did not change at the follow-up. Moreover, there was no correlation between the initial levels of vitamin D and the corresponding increases in the PTH values.

CONCLUSION

If used as monotherapy in hepatitis B patients for a 12-month period, TDF is not associated with changes in either eGFR or a panel of urinary biomarkers. Serum and urinary electrolytes also remained unchanged. Of note, a significant increase in the PTH was found, although not related to the 25(OH)vitamin D initial status.

The Incidence and Clinical Characteristics of Acute Serum Creatinine Elevation more than 1.5 mg/dL among the Patients Treated with Tenofovir/Emtricitabine-containing HAART Regimens

Background

The combination of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) has been the first choice nucleoside reverse transcriptase inhibitor (NRTI) according to many reliable antiretroviral treatment (ART) guidelines because of its high efficacy. However, TDF-related renal toxicity reported in Western countries is a challenging issue regarding clinical use. We conducted this study to evaluate the incidence and characteristics of an acute increase in serum creatinine (Cr) level > 1.5 mg/dL among TDF/FTC-based highly active antiretroviral treatment (HAART)-treated patients.

Materials and Methods

We retrospectively reviewed the medical records of 205 HIV-infected patients treated with TDF/FTC-containing regimens between 1 February 2010 and 30 April 2014. Three groups of TDF/FTC + ritonavir-boosted protease inhibitor (PI/r), TDF/FTC + non-nucleoside reverse transcriptase inhibitor (NNRTI), and TDF/FTC + integrase strand transfer inhibitor (INSTI), and three PI/r subgroups of TDF/FTC + lopinavir (LPV)/r, TDF/FTC + atazanavir (ATV)/r, TDF/FTC + darunavir (DRV)/r were evaluated.

Results

A total 136 patients (91 in the TDF/FTC + PI/r group, 20 in the TDF/FTC + NNRTI group and 25 in the TDF/FTC + INSTI group) were included in the statistical analysis. Four cases (4.9%; all in the TDF/FTC + PI/r group) among 136 patients showed an acute increase in serum Cr more than 1.5 mg/dL, so the overall incidence was 2.8 cases per 100 patient-years. One case was a patient treated with TDF/FTC + LPV/r, and the others were treated with TDF/FTC + ATV/r. No case of an acute increase in serum Cr was observed in the TDF/FTC + DRV/r group. The incidence of serum Cr increase more than 1.5 mg/dL in TDF/FTC + PI/r group was 4.0 cases per 100 patient-years.

Conclusion

Although only a small number of patients were evaluated retrospectively from a single center, the TDF/FTC + PI/r regimen may have been related with relatively higher tendency of increment of serum Cr level. These findings reinforce the importance of close follow-ups of HIV-infected patients treated with the TDF/FTC + PI/r regimens.

Antiretroviral resistance at virological failure in the NEAT 001/ANRS 143 trial: raltegravir plus darunavir/ritonavir or tenofovir/emtricitabine plus darunavir/ritonavir as first-line ART

OBJECTIVES

To describe the pattern of drug resistance at virological failure in the NEAT001/ANRS143 trial (first-line treatment with ritonavir-boosted darunavir plus either tenofovir/emtricitabine or raltegravir).

METHODS

Genotypic testing was performed at baseline for reverse transcriptase (RT) and protease genes and for RT, protease and integrase (IN) genes for patients with a confirmed viral load (VL) >50 copies/mL or any single VL >500 copies/mL during or after week 32.

RESULTS

A resistance test was obtained for 110/805 (13.7%) randomized participants qualifying for resistance analysis (61/401 of participants in the raltegravir arm and 49/404 of participants in the tenofovir/emtricitabine arm). No resistance-associated mutation (RAM) was observed in the tenofovir/emtricitabine plus darunavir/ritonavir arm, and all further analyses were limited to the raltegravir plus darunavir arm. In this group, 15/55 (27.3%) participants had viruses with IN RAMs (12 N155H alone, 1 N155H + Q148R, 1 F121Y and 1 Y143C), 2/53 (3.8%) with nucleotide analogue RT inhibitor RAMs (K65R, M41L) and 1/57 (1.8%) with primary protease RAM (L76V). The frequency of IN mutations at failure was significantly associated with baseline VL: 7.1% for a VL of <100,000 copies/mL, 25.0% for a VL of ≥100,000 copies/mL and <500,000 copies/mL and 53.8% for a VL of ≥500,000 copies/mL (PTREND = 0.007). Of note, 4/15 participants with IN RAM had a VL < 200 copies/mL at time of testing.

CONCLUSIONS

In the NEAT001/ANRS143 trial, there was no RAM at virological failure in the standard tenofovir/emtricitabine plus darunavir/ritonavir regimen, contrasting with a rate of 29.5% (mostly IN mutations) in the raltegravir plus darunavir/ritonavir NRTI-sparing regimen. The cumulative risk of IN RAM after 96 weeks of follow-up in participants initiating ART with raltegravir plus darunavir/ritonavir was 3.9%.

Long-Term Follow-Up of Proteinuria and Estimated Glomerular Filtration Rate in HIV-Infected Patients with Tubular Proteinuria

Objective

The objective of this prospective observational study was to describe the evolution of tubular proteinuria detected in HIV-infected patients, and to evaluate the impact of tenofovir disoproxil fumarate (TDF) discontinuation.

Methods

Proteinuria and estimated glomerular filtration rate (eGFR) were followed during a median duration of 32 months, in 81 HIV-infected patients with tubular proteinuria and eGFR ≥ 60 ml/min/1.73 m² (determined using the Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration equation). Tubular proteinuria was defined by urine protein to creatinine ratio (uPCR) ≥200 mg/g and albumin to protein ratio (uAPR) <0.4.

Results

Twenty per cent of patients had persistence of tubular proteinuria: TDF continuation was the main factor associated with this persistence [OR 9.0; 95%CI: 1.9–41.4; p = 0.01]. Among the 23 patients who discontinued TDF, uPCR returned below the threshold of 200 mg/g in 11 patients. Overall, eGFR decreased with a mean rate of decline of 3.8 ml/min/1.73m²/year. The decline in eGFR was lesser after discontinuation of TDF (5.8 ml/min/1.73m²/year during TDF exposure versus 3 ml/min/1.73m²/year after TDF discontinuation; p = 0.01).

Conclusions

The continuation of TDF was the main factor associated with the persistence of proteinuria. Moreover, proteinuria was normalized in only half of the patients who discontinued TDF. The clinical significance of TDF-related low level of proteinuria as a factor associated with renal disease progression and bone loss remains poorly understood.

Kidney dysfunction associated with tenofovir exposure in human immunodeficiency virus-1-infected Taiwanese patients

BACKGROUND/PURPOSE

Tenofovir disoproxil fumarate (TDF) is associated with kidney tubular dysfunction, for which the risk may vary among patients of different ethnicities. Data are limited, however, on the association between renal function changes and TDF exposure in human immunodeficiency virus (HIV)-infected Taiwanese patients.

METHODS

Medical records of HIV-infected Taiwanese patients seeking HIV care at a university hospital from 2011 to 2014 were reviewed. The change of estimated glomerular filtration rate (eGFR) was compared between patients not receiving combination antiretroviral therapy (cART) and those starting cART with or without TDF. The determinants of annual eGFR changes and factors associated with greater annual eGFR decline in TDF-exposed patients were explored.

RESULTS

A total of 775 patients were included: 140 were cART-naïve, 393 received TDF-containing cART, and 242 received cART without TDF. Compared with cART-naïve patients, the annual eGFR decline was greater in TDF-exposed patients (0.57 ± 8.6 mL/min/1.73 m² and 2.7 ± 8.9 mL/min/1.73 m², p = 0.012). The annual eGFR decline between patients receiving cART with or without TDF was similar (2.7 ± 8.9 mL/min/1.73 m² and 1.8 ± 8.3 mL/min/1.73 m², p = 0.567). Diabetes was associated with worsening eGFR decline in all studied patients. TDF exposure correlated with an additional annual eGFR decline of 2.73 mL/min/1.73 m² (95% confidence interval 0.139-5.326, p = 0.039) in patients with CD4 count < 350 cells/μL. Among TDF-exposed patients, the factors associated with annual eGFR decline of > 3 mL/min/1.73 m² were higher baseline eGFR and lower CD4 counts.

CONCLUSION

Among HIV-infected Taiwanese patients, cART exposure correlated with the decline of renal function. However, TDF-exposed patients are more likely to have prominent eGFR decline, especially those with higher baseline eGFR, advanced HIV disease, and diabetes.

Low Incidence of Renal Dysfunction among HIV-Infected Patients on a Tenofovir-Based First Line Antiretroviral Treatment Regimen in Myanmar

BACKGROUND

Since 2004, Médecins Sans Frontières-Switzerland has provided treatment and care for people living with HIV in Dawei, Myanmar. Renal function is routinely monitored in patients on tenofovir (TDF)-based antiretroviral treatment (ART), and this provides an opportunity to measure incidence and risk factors for renal dysfunction.

METHODS

We used routinely collected program data on all patients aged ≥15 years starting first-line TDF-based ART between January 2012 and December 2013. Creatinine clearance (CrCl) was assessed at base line and six-monthly, with renal dysfunction defined as CrCl < 50 ml/min/1.73 m2. We calculated incidence of renal dysfunction and used Cox regression analysis to identify associated risk factors.

RESULTS

There were 1391 patients, of whom 1372 had normal renal function at baseline. Of these, 86 (6.3%) developed renal dysfunction during a median time of follow-up 1.14 years with an incidence rate of 5.4 per 100 person-years: 78 had CrCl between 30-50 ml/min/1.73 m2 and were maintained on TDF-based ART, but 5 were changed to another regimen: 4 because of CrCl <30 ml/min/1.73 m2. Risk factors for renal dysfunction included age ≥45 years, diagnosed diabetes, underlying renal disease, underweight and CD4 count <200 cells/mm3. There were 19 patients with baseline renal dysfunction and all continued on TDF-based ART: CrCl stayed between 30-49 ml/min/1.73 m2 in five patients while the remainder regained normal renal function.

CONCLUSIONS

In a resource-poor country like Myanmar, the low incidence of renal toxicity in our patient cohort suggests that routine assessment of CrCl may not be needed and could be targeted to high risk groups if resources permit.

Role of oral pre-exposure prophylaxis (PrEP) in current and future HIV prevention strategies

Treatment as prevention is expected to have a major role in reducing HIV incidence, but other prevention interventions will also be required to bring the epidemic under control, particularly among key populations. One or more forms of pre-exposure prophylaxis (PrEP) will likely play a critical role. Oral PrEP with emtricitabine-tenofovir (Truvada®) is currently available in the US and some other countries, but uptake has been slow. We review the concerns that have contributed to this slow uptake and discuss current and future research in this critical area of HIV prevention research.

Tenofovir alafenamide versus tenofovir disoproxil fumarate, coformulated with elvitegravir, cobicistat, and emtricitabine, for initial treatment of HIV-1 infection: two randomised, double-blind, phase 3, non-inferiority trials

BACKGROUND

Tenofovir disoproxil fumarate can cause renal and bone toxic effects related to high plasma tenofovir concentrations. Tenofovir alafenamide is a novel tenofovir prodrug with a 90% reduction in plasma tenofovir concentrations. Tenofovir alafenamide-containing regimens can have improved renal and bone safety compared with tenofovir disoproxil fumarate-containing regimens.

METHODS

In these two controlled, double-blind phase 3 studies, we recruited treatment-naive HIV-infected patients with an estimated creatinine clearance of 50 mL per min or higher from 178 outpatient centres in 16 countries. Patients were randomly assigned (1:1) to receive once-daily oral tablets containing 150 mg elvitegravir, 150 mg cobicistat, 200 mg emtricitabine, and 10 mg tenofovir alafenamide (E/C/F/tenofovir alafenamide) or 300 mg tenofovir disoproxil fumarate (E/C/F/tenofovir disoproxil fumarate) with matching placebo. Randomisation was done by a computer-generated allocation sequence (block size 4) and was stratified by HIV-1 RNA, CD4 count, and region (USA or ex-USA). Investigators, patients, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug were included in the primary intention-to-treat efficacy and safety analyses. The main outcomes were the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by the the US Food and Drug Adminstration (FDA) snapshot algorithm (pre-specified non-inferiority margin of 12%) and pre-specified renal and bone endpoints at 48 weeks. These studies are registered with ClinicalTrials.gov, numbers NCT01780506 and NCT01797445.

FINDINGS

We recruited patients from Jan 22, 2013, to Nov 4, 2013 (2175 screened and 1744 randomly assigned), and gave treatment to 1733 patients (866 given E/C/F/tenofovir alafenamide and 867 given E/C/F/tenofovir disoproxil fumarate). E/C/F/tenofovir alafenamide was non-inferior to E/C/F/tenofovir disoproxil fumarate, with 800 (92%) of 866 patients in the tenofovir alafenamide group and 784 (90%) of 867 patients in the tenofovir disoproxil fumarate group having plasma HIV-1 RNA less than 50 copies per mL (adjusted difference 2·0%, 95% CI -0·7 to 4·7). Patients given E/C/F/tenofovir alafenamide had significantly smaller mean serum creatinine increases than those given E/C/F/tenofovir disoproxil fumarate (0·08 vs 0·12 mg/dL; p<0·0001), significantly less proteinuria (median % change -3 vs 20; p<0·0001), and a significantly smaller decrease in bone mineral density at spine (mean % change -1·30 vs -2·86; p<0·0001) and hip (-0·66 vs -2·95; p<0·0001) at 48 weeks.

INTERPRETATION

Through 48 weeks, more than 90% of patients given E/C/F/tenofovir alafenamide or E/C/F/tenofovir disoproxil fumarate had virological success. Renal and bone effects were significantly reduced in patients given E/C/F/tenofovir alafenamide. Although these studies do not have the power to assess clinical safety events such as renal failure and fractures, our data suggest that E/C/F/tenofovir alafenamide will have a favourable long-term renal and bone safety profile.

FUNDING

Gilead Sciences.

Urine alpha1-microglobulin is a better marker for early tubular dysfunction than beta2-microglobulin among tenofovir-exposed human immunodeficiency virus-infected men who have sex with men

OBJECTIVES

Men who have sex with men are at risk of tenofovir nephrotoxicity due to its wide use in both treatment and prophylaxis for human immunodeficiency virus infection, but little is known about the urinary biomarkers of early renal dysfunction in this population. This study aims to identify useful biomarkers of early renal dysfunction among human immunodeficiency virus-infected men who have sex with men exposed to tenofovir.

METHODS

In a cross-sectional study urinary alpha1-microglobulin, beta2-microglobulin, N-acetyl-β-d-glucosaminidase and albumin were measured and expressed as the ratio-to-creatinine in 239 human immunodeficiency virus-infected men who have sex with men who were treatment naïve or receiving antiretroviral therapy with tenofovir-containing or non-tenofovir-containing regimens. Additionally, 56 patients in the non-antiretroviral therapy group started a tenofovir-containing regimen and were assessed after 3 and 6 months on antiretroviral therapy.

RESULTS

Both the frequency of alpha1-microglobulin proteinuria (alpha1-microglobulin-creatinine ratio >25.8mg/g) and the median urinary alpha1-microglobulin-creatinine ratio were higher in the tenofovir disoproxil fumarate group than the other two groups (all p<0.05). A higher frequency of beta2-microglobulin proteinuria (beta2-microglobulin-creatinine ratio >0.68mg/g) was also observed in the tenofovir group (28.9%) compared to the non-tenofovir group (13.6%, p=0.024). There were no significant differences between groups for N-acetyl-β-d-glucosaminidase and albumin. In the longitudinal study, the median urinary alpha1-microglobulin-creatinine ratio after 3 and 6 months on tenofovir-containing therapy (16.8 and 17.3mg/g) was higher than baseline (12.3mg/g, p=0.023 and 0.011, respectively), while no statistically important changes were observed in urinary beta2-microglobulin-creatinine ratio or in the other biomarkers after 3 and 6 months on antiretroviral therapy (all p>0.05).

CONCLUSION

Urinary alpha1-microglobulin seems to be a more sensitive and stable indicator of tubular dysfunction than urinary beta2-microglobulin for assessing tenofovir-related nephrotoxicity and can be significantly altered after tenofovir exposure.

Proximal tubular dysfunction and kidney injury associated with tenofovir in HIV patients: a case series

Background

Tenofovir disoproxil fumarate (TDF) may cause acute kidney injury and proximal tubular dysfunction. However, no detailed studies document urinary phosphate wasting as a marker of TDF-induced tubulopathy.

Methods

Records of HIV-infected patients with presumed TDF toxicity were reviewed. We describe the characteristics and clinical course of 15 patients who had documented elevated (>20%) fractional excretion of phosphate (FEphos).

Results

Patients were predominantly Caucasian and male (73 and 80%, respectively), with a mean age of 56 years (range 38–76). Of the 15 patients, 11 had a estimated glomerular filtration rate (eGFR) of >90 mL/min/1.73² at time of TDF initiation. The mean duration of TDF therapy prior to diagnosis of TDF toxicity was 64 months. Mean FEphos was 34% (range 20–62). The mean eGFR at TDF initiation was 104 mL/min/1.73 m² [standard deviation (SD) 17.0] with a gradual decline to 69 mL/min/1.73 m² (SD 19.0) by the time of TDF discontinuation. Of 10 patients with repeated FEphos after TDF discontinuation, 9 had improvement of their FEphos. Of these individuals, 6 had normalization of their FEphos. Estimated GFR improved in 12 patients after discontinuation of TDF, though importantly, none returned to their baseline eGFR.

Conclusions

Urinary phosphate wasting is a sensitive marker for TDF-induced proximal tubulopathy and is associated with unrecognized and permanent renal function decline. Tubular dysfunction can develop after years of TDF therapy in those with normal kidney function at the time of drug initiation. This suggests that continuing vigilance be maintained in all those on TDF.

Incidence and risk factors for tenofovir-associated renal toxicity in HIV-infected patients

BACKGROUND

Since the beginning of highly active antiretroviral therapy utilization, the association of renal impairment with treatment toxicity is more prevalent. Tenofovir disoproxil fumarate (TDF) side effects include renal toxicity.

OBJECTIVE

To assess the incidence of renal damage in human immunodeficiency virus (HIV)-positive patients treated with TDF and to identify associated potential risk factors.

SETTING

A public university tertiary 450-beds hospital in Spain.

METHOD

Retrospective, longitudinal observational study that included adult HIV-1-infected patients treated with TDF. Patient´s treated with TDF from January 2010 to December 2012 were included. Patient follow-up started when initiating treatment with TDF up until either end of treatment or end of study (July 31, 2013). The estimated glomerular filtration rate was calculated using the four-variable modification of diet in renal disease. Renal toxicity was classified as moderate [estimated glomerular filtration rate (eGFR) < 60 ml/min] or severe (eGFR < 30 ml/min). The incidence rate for moderate and severe renal insufficiency was calculated as number of cases per 1000 patient-year. A univariate analysis and binary logistic regression was carried out in order to identify risk factors associated with renal toxicity by using the forward stepwise method (likelihood ratio)

MAIN OUTCOME MEASURE

Incidence rate for moderate and severe renal insufficiency (RI) RESULTS: 451 patients were included in the study. The incidence rate of moderate RI was 29.2 cases per 1000 person-year (95% CI 22.1-36.3), whereas the incidence of severe RI was 2.2 cases per 1000 person-year (95% CI 0.3-4.1). Multivariate analysis confirmed an independent association with the risk of kidney damage for age (OR 1.08 95% CI 1.05-1.12), time on treatment with TDF (OR 1.16 95% CI 1.04-1.30), baseline creatinine (OR 49.80 95% CI 7.90-311.92) and treatment with NNRTIs (OR 0.45 95% CI 0.24-0.83).

CONCLUSION

Mild to moderate renal failure is a frequent complication during treatment with TDF although severe renal impairment is scarce. Risk factors include age, duration of treatment with TDF, elevated baseline creatinine levels, and treatment with protease inhibitor boosted with ritonavir combinations.

Monitoring of kidney function in HIV-positive patients

HIV-positive patients are at increased risk of developing chronic kidney disease. Although guidelines recommend regular monitoring of renal function in individuals living with HIV, the optimal frequency remains to be defined. In this review, we discuss the renal syndromes that may be identified at an earlier stage via routine assessment of kidney function, and provide guidance in terms of the frequency of monitoring, the most useful tests to perform, and their clinical significance. Specifically, we address whether annual monitoring of kidney function is appropriate for the majority of HIV-positive patients.

Systematic Literature Review and Meta-Analysis of Renal Function in Human Immunodeficiency Virus (HIV)-Infected Patients Treated with Atazanavir (ATV)-Based Regimens

Some HIV antiretroviral therapies (ART) have been associated with renal toxicities, which become of increasing concern as HIV-infected patients age and develop comorbidities. The objective of this study was to evaluate the relative impact of atazanavir (ATV)-based regimens on the renal function of adult patients with HIV. We conducted a systematic literature review by searching PubMed, EMBASE, Cochrane library, and the CRD from 2000 until March 2013. Major HIV-related conferences occurring in the past two years were also searched. All randomized clinical trials and large cohort studies assessing renal function in treatment-naïve and/or treatment-experienced HIV patients on ATV-based regimens were included. Fixed-effect mixed-treatment network analyses were carried out on the most frequently reported renal outcomes. 23 studies met the inclusion criteria, and change in estimated glomerular filtration rate (eGFR) from baseline to 48 weeks was identified as the main outcome. Two networks including, respectively, six studies (using the Cockcroft-Gault method) and four studies (using MDRD and CKD-EPI) were analysed. With CG network, ATV/r + TDF/FTC was associated with lower impact on the decline of eGFR than ATV/cobicistat + TDF/FTC but with higher decrease in eGFR than ATV/r + ABC/3TC (difference in mean change from baseline in eGFR respectively +3.67 and -3.89). The use of ATV/cobicistat + TDF/FTC led to a similar decline in eGFR as EVG/cobicistat/TDF/FTC. With respect to third agents combined with TDF/FTC, ATV/r had a lower increase in eGFR in comparison to EFV, and no difference was shown when compared to SQV/r and DRV/r. The effect of ATV-based regimens on renal function at 48 weeks appears similar to other ART regimens and appears to be modest regardless of boosting agent or backbone, although TDF containing backbones consistently leads to greater decline in eGFR.

Factors associated with daily tenofovir exposure in Thai subjects taking combination antiretroviral therapy

Tenofovir (TFV) exposure is associated with antiretroviral efficacy and risk of kidney disease. There is evidence of high interindividual variability of the pharmacokinetics of TFV. The effect of several clinical conditions on the pharmacokinetics of TFV has been observed and may partly explain its variability. We assessed factors influencing the pharmacokinetics of TFV in Thai patients. Thirty participants (50% female) taking efavirenz- or ritonavir-boosted protease inhibitor-based regimens were investigated. Intensive pharmacokinetic sampling was performed over 24 h. Multivariate geometric mean regression models adjusted for covariates with p ≤ 0.2 in univariate analysis were developed. The median age was 41 years. Five participants [three taking a protease inhibitor (PI) and two taking efavirenz (EFV)] had mild renal dysfunction [estimated glomerular filtration rate (eGFR) 60-90 ml/min/1.73 m(2); range 72-89]. TFV AUC0-24 was 23% (95% CI 1-49%; p=0.04) higher in those taking PI vs. EFV, 39% (95% CI 5-84%; p=0.02) higher in those with mild renal dysfunction, and reduced by 16% (95% CI 5-26%; p=0.008) with each 10 kg body weight increase, after adjusting for sex and duration of TFV exposure. In PI-treated subjects TFV AUC0-24 increased by 3% (0.3-6%; p=0.03) for each mg·h/liter increase in ritonavir (RTV) AUC0-24 after adjusting for sex, weight, mild renal impairment, and proximal renal tubular dysfunction. Significantly higher TFV exposures were independently associated with PI regimens, mild renal impairment, lower body weight, and increasing RTV AUC0-24. Clinicians should be aware of the effect of these factors on TFV exposure when this drug is prescribed.

Development and validation of a risk score for chronic kidney disease in HIV infection using prospective cohort data from the D:A:D study

BACKGROUND

Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice.

METHODS AND FINDINGS

A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with ≥3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR ≤ 60 ml/min/1.73 m2. Poisson regression was used to develop a risk score, externally validated on two independent cohorts. In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1:393 chance of developing CKD in the next 5 y in the low risk group (risk score < 0, 33 events), rising to 1:47 and 1:6 in the medium (risk score 0-4, 103 events) and high risk groups (risk score ≥ 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria.

CONCLUSIONS

Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.

Efficacy and safety of treatment simplification to atazanavir/ritonavir + lamivudine in HIV-infected patients with virological suppression: 144 week follow-up of the AtLaS pilot study

OBJECTIVES

AtLaS was a single-arm pilot study that demonstrated promising efficacy and safety of treatment simplification to a dual regimen with atazanavir/ritonavir + lamivudine in virologically suppressed HIV-positive patients. Here, we report data from the 144 week follow-up.

METHODS

At baseline, patients treated with a three-drug atazanavir/ritonavir-based regimen were switched to 300/100 mg of atazanavir/ritonavir plus 300 mg of lamivudine once daily. Major clinical events, laboratory parameters, neurocognitive performance, bone composition and body fat distribution were monitored. Treatment failure was defined as a discontinuation/switch of the regimen or virological failure (HIV-RNA >50 copies/mL in two consecutive determinations or a single level above 1000 copies/mL).

RESULTS

After 144 weeks, 9/40 (22.5%) treatment failures occurred, including two virological failures (Weeks 48 and 53, without resistance). A significant increase in the CD4 count was observed at Week 96 (+124 cells/mm(3); P = 0.002) and Week 144 (+94 cells/mm(3); P = 0.008). After 144 weeks, a significant increase in total cholesterol (+25 mg/dL; P = 0.001), HDL cholesterol (+6 mg/dL; P = 0.024) and LDL cholesterol (+12 mg/dL; P = 0.008) was observed, without any change in triglyceride levels, total cholesterol/HDL ratio or LDL/HDL ratio. A significant increase in the estimated glomerular filtration rate (+25 mL/min/1.73 m(2); P < 0.001) and lumbar spine T-score and Z-score (+0.2, P = 0.011; and +0.35, P = 0.001, respectively) and a decrease in trunk fat (-1.898 g; P = 0.005) were also observed. Neurocognitive function did not decline over time. Concerning safety, 10 moderate to severe adverse events were recorded in eight patients; overall seven cases of renal colic (possibly treatment related) were observed, leading to a discontinuation of treatment in two patients.

CONCLUSIONS

Data from the 144 week follow-up suggested good long-term efficacy of the simplification strategy that was investigated, with rare virological failure and a potential for improvement of the CD4 count, renal function and bone mineral density. This strategy warrants further investigation in a randomized trial.

Differentiating HIV-associated nephropathy from antiretroviral drug-induced nephropathy: a clinical challenge

With the introduction of potent combination antiretroviral therapy (cART) into clinical practice, HIV-infected patients have garnered much benefit. However, kidney disease continues to be a potential complication in this group. Whereas HIV-associated nephropathy (HIVAN) was the major renal complication prior to cART, co-morbid diseases and adverse renal effects of various drugs, in particular cART, now complicate the landscape. Clinicians now must differentiate HIVAN from cART nephrotoxicity. While sometimes this is easy and relatively straightforward, often the clinician faces a difficult challenge distinguishing these two etiologies of kidney disease. This review will discuss HIVAN and cART-related kidney disease and review the clinical and laboratory data that may be useful in differentiating these processes. Often, however, kidney biopsy may be required to differentiate HIVAN from cART nephrotoxicity as well as other kidney lesions associated with concurrent co-morbidities, both infectious and non-infectious.

Differences in nephrotoxicity risk and renal effects among anti-viral therapies against hepatitis B

BACKGROUND

Results are conflicting with respect to the renal effects of anti-viral agents used for hepatitis B virus infection.

AIM

To compare short and long-term renal effects in real-life settings and to determine risk factors for renal impairment during treatment.

METHODS

2221 treatment-naïve patients were enrolled. Among these, 895 (302 lamivudine, 27 telbivudine, 282 entecavir, 273 tenofovir and 11 adefovir initiated patients) had 'repeated measures' of creatinine (baseline, 1st, 6th, 12th and 24th month of treatment). Telbivudine and adefovir groups were excluded from further analysis because of the low number of patients. We calculated the glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) formula at each time point. Hypophosphataemia was also recorded. Risk factors for renal impairment were analysed.

RESULTS

Tenofovir caused a decline in GFR at each time point when compared to baseline levels. However, lamivudine and entecavir did not change GFR. GFR-shifting from ≥90 to 60-89 mL/min/1.73 m(2) was comparable among groups. The proportion of patients whose baseline creatinine increased more than 25% was comparable among all anti-virals. GFR showed a decline in patients who switched from entecavir to tenofovir. One patient with compensated cirrhosis needed to change from tenofovir because of renal safety. Seven and three patients developed transient hypophosphataemia in the tenofovir and lamivudine groups, respectively.

CONCLUSIONS

Although tenofovir caused a decline in GFR, differences between the anti-viral agents do not appear to be so impressive. In patients with and without renal risk factors at baseline, there is no impact of anti-virals, including tenofovir.

Long-term treatment with tenofovir in Asian-American chronic hepatitis B patients is associated with abnormal renal phosphate handling

BACKGROUND

Increased risk of defective urinary phosphate reabsorption and osteoporosis has been reported in HIV and chronic hepatitis B (CHB) patients treated with tenofovir disoproxil fumarate (TDF).

AIMS

Goals of this study were to evaluate the prevalence of renal phosphate wasting and abnormal bone mineral density in CHB patients taking TDF compared to CHB patients treated with entecavir (ETV) and untreated CHB patients.

METHODS

This is a cross-sectional study of 146 consecutive Asian-American CHB patients who were treatment naïve (n = 60) or treated with either TDF (n = 42) or ETV (n = 44). Proximal tubular handling of phosphate was assessed by the maximal rate of tubular reabsorption of phosphate (TmPO4) divided by glomerular filtration rate (GFR) (TmPO4/GFR). Bone mineral density (BMD) was measured using dual X-ray absorptiometry.

RESULTS

TmPO4/GFR was similar among CHB patients treated with TDF compared to untreated patients and patients taking ETV. However, among patients treated with ≥18 months of TDF or ETV, prevalence of abnormal TmPO4/GFR was higher among patients treated with TDF compared to ETV (48.5 % (16/33) vs. 12.5 % (3/24), p = 0.005). Overall prevalence of osteoporosis in this cohort of CHB patients was 14 %, with no significant difference between the three groups. Renal phosphate handling did not correlate with osteoporosis.

CONCLUSIONS

Chronic hepatitis B patients treated with ≥18 months of TDF experienced an increased risk of proximal tubular dysfunction. TDF did not increase the risk of osteoporosis. Longitudinal studies are needed to confirm these findings.

Changes in glomerular kidney function among HIV-1-uninfected men and women receiving emtricitabine-tenofovir disoproxil fumarate preexposure prophylaxis: a randomized clinical trial

IMPORTANCE

Tenofovir disoproxil fumarate (TDF) use has been associated with declines in the estimated glomerular filtration rate (eGFR) when used as part of antiretroviral treatment by persons with human immunodeficiency virus (HIV) type 1, but limited data are available for risk when used as preexposure prophylaxis (PrEP) for HIV-1 prevention.

OBJECTIVE

To determine whether TDF-based PrEP causes eGFR decline in HIV-1-uninfected adults.

DESIGN, SETTING, AND PARTICIPANTS

A per-protocol safety analysis of changes in eGFR in the Partners PrEP Study, a randomized, placebo-controlled trial of daily oral TDF and emtricitabine (FTC)-TDF PrEP among heterosexual HIV-1-uninfected members of serodiscordant couples in Kenya and Uganda. The trial was conducted from 2008 to 2012.

MAIN OUTCOMES AND MEASURES

Predefined outcomes of this analysis were mean eGFR change and a 25% or greater eGFR decline from baseline. The eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

Of 4640 participants in the once-daily TDF (n = 1548), FTC-TDF (n = 1545), or placebo (n = 1547) groups, 63% were men. At enrollment, median age was 35 years (range, 18-64 years), and mean eGFR was 130 mL/min/1.73 m². During a median follow-up of 18 months (interquartile range 12-27 months), mean within-group eGFR change from baseline was +0.14 mL/min/1.73 m² for TDF, -0.22 mL/min/1.73 m² for FTC-TDF, and +1.37 mL/min/1.73 m² for placebo, translating into average declines in eGFR attributable to PrEP vs placebo of -1.23 mL/min/1.73 m² (95% CI, -2.06 to -0.40; P = .004) for TDF and -1.59 mL/min/1.73 m² (95% CI, -2.44 to -0.74; P < .001) for FTC-TDF. The difference in mean eGFR between PrEP and placebo appeared by 1 month after randomization, was stable through 12 months, and then appeared to wane thereafter. The respective proportions of persons who developed a confirmed 25% or greater eGFR decline from baseline by 12 and 24 months was 1.3% and 1.8% for TDF and 1.2% and 2.5% for FTC-TDF, and these frequencies were not statistically different from the confirmed decline in the placebo group (0.9% and 1.3% by 12 and 24 months, respectively).

CONCLUSIONS AND RELEVANCE

In this large randomized, placebo-controlled trial among heterosexual persons, with median follow-up of 18 months and maximum follow-up of 36 months, daily oral TDF-based PrEP resulted in a small but nonprogressive decline in eGFR that was not accompanied by a substantial increase in the risk of clinically relevant (≥25%) eGFR decline.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00557245.

Diminished impact of ethnicity as a risk factor for chronic kidney disease in the current HIV treatment era

BACKGROUND

Chronic kidney disease (CKD) is an important comorbidity during human immunodeficiency virus (HIV) infection. Historically, HIV-associated nephropathy has been the predominant cause of CKD and has primarily been observed in people of African ancestry. This study aims to investigate the role of ethnicity in relation to CKD risk in recent years.

METHODS

Analyses were performed including 16 836 patients from the Dutch AIDS Therapy Evaluation in the Netherlands (ATHENA) cohort. Baseline was defined as the first available creatinine level measurement after 1 January 2007; CKD was defined as a glomerular filtration rate of <60 mL/min/1.73 m(2). The associations between ethnicity and both prevalent CKD at baseline and incident CKD during follow-up were analyzed.

RESULTS

The prevalence of baseline CKD was 2.7% (460 of 16 836 patients). Birth in a sub-Saharan African country (hereafter, "SSA origin") was significantly associated with baseline CKD (adjusted odds ratio 1.49; 95% confidence interval [CI], 1.04-2.13). During follow-up (median duration, 4.7 years; interquartile range, 2.4-5.2), the rate of incident CKD was 6.0 events per 1000 person-years. The risk of newly developing CKD was similar between patients of SSA origin and those born in Western Europe, Australia, or New Zealand (adjusted hazard ratio, 1.00; 95% CI, .63-1.59).

CONCLUSIONS

Among HIV-infected patients in the Netherlands, being of SSA origin was associated with a higher baseline CKD prevalence but had no impact on newly developing CKD over time. This suggests a shift in the etiology of CKD from HIV-associated nephropathy toward other etiologies.

Protease Inhibitors and Renal Function in Patients with HIV Infection: a Systematic Review

INTRODUCTION

Despite antiretroviral (ARV) therapy reducing renal disease in human immunodeficiency virus overall, there is concern that certain ARVs, particularly tenofovir disoproxil fumarate (TDF) with or without a boosted protease inhibitor (PI), may reduce renal function over time. It is not known whether effects seen with PI-based regimens are independent, result from interactions with TDF coadministration, or are artefactual owing to inhibition of renal tubular creatinine transport by ritonavir or cobicistat pharmacoenhancement. The aim of this review was to conduct a systematic review of studies, weighted toward high-quality evidence, examining changes in renal function over time with PI-based regimens.

METHODS

PubMed, Embase, and Medline databases and conference abstracts were searched using pre-defined terms for English language articles, published up to and including August 12, 2013, describing changes in renal function over time with PI-based regimens. All available randomized controlled trials (RCTs) were selected; however, to reduce bias, only observational studies recruiting from more than one center and analyzing data from more than 1,000 patients were included. Evidence was qualitatively evaluated according to levels established by the Oxford Centre for Evidence-Based Medicine (OCEBM).

RESULTS

A total of 2,322 articles were retrieved by the initial search. Of these, 37 were selected for full review, comprising 24 RCTs (OCEBM Level 1 evidence: 4 reports of fully double-blinded or blinded with respect to the PI component). The remaining 20 RCTs and 13 observational studies qualified as OCEBM Level 2 evidence. Level 1 evidence showed initial but non-progressive increases in serum creatinine and corresponding decreases in estimated glomerular filtration rate (eGFR), suggesting an effect on renal tubular transport of creatinine. Level 2 evidence suggested that atazanavir and lopinavir especially in combination with TDF were associated with non-progressive reductions in eGFR over time, with a decreased risk for the development of chronic kidney disease (CKD) on cessation and without the development of advanced CKD or end-stage renal disease (ESRD); whether these reductions were independent or associated with interactions with coadministered TDF could not be established with certainty. Data on darunavir were insufficient to draw any conclusions. The principal limitation of the reviewed studies was the lack of standardization of creatinine measurements in virtually all studies and the lack of corroborative data on changes in proteinuria or other indices of renal function.

DISCUSSION

In this review, there was little evidence for progressive changes in eGFR, or the development of advanced CKD, or ESRD with lopinavir or atazanavir. Further long-term studies, employing a wide range of validated renal function assessments, are required to fully evaluate potential association of PIs with CKD.

Race and other risk factors for incident proteinuria in a national cohort of HIV-infected veterans

BACKGROUND

Proteinuria in human immunodeficiency virus (HIV)-infected individuals has been associated with poorer outcomes. We examined risk factors associated with the development of proteinuria in a national registry of HIV-infected veterans.

METHODS

A total of 21,129 HIV-infected veterans of black and white race without preexisting kidney disease were receiving health care in the Veterans' Health Administration (VHA) medical system between 1997 and 2011. Using the VHA electronic record system, we identified kidney-related risk factors (hypertension, diabetes, and cardiovascular disease) and HIV-related risk factors (CD4 lymphocyte count, HIV RNA level, hepatitis C virus, and hepatitis B virus) for developing proteinuria. Proteinuria was defined by 2 consecutive dipstick measures of 1 or higher. The Fine-Gray competing risk model was used to estimate association between clinical variables and incident proteinuria, while accounting for intervening mortality events.

RESULTS

During follow-up (median = 5.3 years), 7031 patients developed proteinuria. Overall, black race compared with white race was associated with a higher risk of proteinuria {hazard ratio [95% confidence interval (CI)] = 1.51 [1.43 to 1.59]}, but the association was stronger at younger ages (P interaction <0.001). Age-stratified risk of proteinuria for blacks relative to whites was greatest among veterans <30 years [2.19 (1.66 to 2.89)] and the risk diminished with increasing age [1.14 (0.97 to 1.34) for >60 years]. We found the race difference to be stronger for the outcome of 2 or higher proteinuria [2.13 (1.89 to 2.39)]. Both HIV-related and traditional risk factors were also associated with incident proteinuria (P < 0.05).

CONCLUSIONS

Compared with whites, risk of proteinuria was higher in black veterans with HIV infection, particularly at younger ages. In both races, HIV- and kidney-related risk factors were associated with higher proteinuria risk.

Monotherapy with boosted PIs as an ART simplification strategy in clinical practice

BACKGROUND

Data on the efficacy of simplifying therapy using darunavir/ritonavir and lopinavir/ritonavir monotherapy in clinical practice remain limited.

METHODS

A retrospective single-centre study including patients initiating darunavir/ritonavir or lopinavir/ritonavir monotherapy with a plasma HIV-1 viral load (pVL) <50 copies/mL and at least one subsequent follow-up visit. The primary endpoint was the percentage of patients remaining free of virological failure (VF; defined as a confirmed pVL >50 copies/mL or as any change in the regimen after a single determination with a pVL >50 copies/mL) during the follow-up. We also evaluated the percentage of patients remaining free of treatment failure (TF; defined as VF or the early discontinuation of monotherapy for any reason) and compared the effectiveness of the two regimens. Effectiveness was evaluated using cumulative survival analysis (at Weeks 48 and 96). Factors associated with VF and TF were analysed using Cox regression.

RESULTS

A total of 522 patients were included (309 receiving lopinavir/ritonavir and 213 receiving darunavir/ritonavir). The median follow-up was 64.3 (30.5-143.0) weeks. The percentage of patients free of VF and TF was 94% (95% CI 91%-96%) and 79% (95% CI 75%-82%) at 48 weeks, respectively, and 86% (95% CI 81%-89%) and 62% (95% CI 57%-67%) at 96 weeks, respectively. The risk of VF was similar for the two regimens (HR=1.0, 95% CI 0.6-1.8; P=0.962). Lopinavir/ritonavir monotherapy was associated with a 1.5-fold greater risk of TF (95% CI 1.1-2.1; P=0.012) and a 2.3-fold greater risk of discontinuation of therapy due to adverse events (95% CI 1.3-3.9; P=0.003).

CONCLUSIONS

The virological efficacy of darunavir/ritonavir and lopinavir/ritonavir monotherapy is high in clinical practice. Treatment discontinuation due to safety issues is more frequent with lopinavir/ritonavir.

A review of the toxicity of HIV medications

Antiretroviral therapy has changed human immunodeficiency virus (HIV) infection from a near-certainly fatal illness to one that can be managed chronically. More patients are taking antiretroviral drugs (ARVs) for longer periods of time, which naturally results in more observed toxicity. Overdose with ARVs is not commonly reported. The most serious overdose outcomes have been reported in neonates who were inadvertently administered supratherapeutic doses of HIV prophylaxis medications. Typical ARV regimens include a "backbone" of two nucleoside reverse transcriptase inhibitors (NRTI) and a "base" of either a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor. New classes of drugs called entry inhibitors and integrase inhibitors have also emerged. Older NRTIs were associated with mitochondrial toxicity, but this is less common in the newer drugs, emtricitabine, lamivudine, and tenofovir. Mitochondrial toxicity results from NRTI inhibition of a mitochondrial DNA polymerase. Mitochondrial toxicity manifests as myopathy, neuropathy, hepatic failure, and lactic acidosis. Routine lactate assessment in asymptomatic patients is not indicated. Lactate concentration should be obtained in patients taking NRTIs who have fatigue, nausea, vomiting, or vague abdominal pain. Mitochondrial toxicity can be fatal and is treated by supportive care and discontinuing NRTIs. Metabolic cofactors like thiamine, carnitine, and riboflavin may be helpful in managing mitochondrial toxicity. Lipodystrophy describes changes in fat distribution and lipid metabolism that have been attributed to both PIs and NRTIs. Lipodystrophy consists of loss of fat around the face (lipoatrophy), increase in truncal fat, and hypertriglyceridemia. There is no specific treatment of lipodystrophy. Clinicians should be able to recognize effects of chronic toxicity of ARVs, especially mitochondrial toxicity.

A consensus statement on the renal monitoring of Australian patients receiving tenofovir based antiviral therapy for HIV/HBV infection

A number of antiviral agents used against Human Immunodeficiency Virus (HIV) infection and hepatitis B virus (HBV) mono or co-infection have been associated with real nephrotoxicity (including tenofovir disoproxil fumarate (TDF), atazanavir, indinavir and lopinavir) or apparent changes in renal function (e.g. cobicistat, ritonavir, rilpivirine and dolutegravir). Patients with HIV are at higher risk of acute and chronic renal dysfunction, so baseline assessment and ongoing monitoring of renal function is an important part of routine management of patients with HIV.

Given the paucity of evidence in this area, we sought to establish a consensus view on how routine monitoring could be performed in Australian patients on ART regimens, especially those involving TDF. A group of nephrologists and prescribers (an HIV physician and a hepatologist) were assembled by Gilead to discuss practical and reasonable renal management strategies for patients particularly those on TDF-based combination regimens (in the case of those with HIV-infection) or on TDF-monotherapy (in the case of HBV-mono infection). The group considered which investigations should be performed as part of routine practice, their frequency, and when specialist renal referral is warranted. The algorithm presented suggests testing for serum creatinine along with plasma phosphate and an assessment of urinary protein (rather than albumin) and glucose.

Here we advocate baseline tests of renal function at initiation of therapy. If creatinine excretion inhibitors (e.g. cobicistat or rilpivirine) are used as part of the ART regimen, we suggest creatinine is rechecked at 4 weeks and this value used as the new baseline. Repeat testing is suggested at 3-monthly intervals for a year and then at least yearly thereafter if no abnormalities are detected. In patients with abnormal baseline results, renal function assessment should be performed at least 6 monthly. In HBV mono-infected patients advocate that a similar testing protocol may be logical.

Association of urine α1-microglobulin with kidney function decline and mortality in HIV-infected women

BACKGROUND AND OBJECTIVES

Despite advances in therapy, HIV-infected individuals remain at higher risk for kidney dysfunction than uninfected individuals. It was hypothesized that urine levels of α1-microglobulin, a biomarker of proximal tubular dysfunction, would predict kidney function decline and mortality risk in HIV-infected and uninfected women.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In the Women's Interagency HIV Study, urine α1-microglobulin and creatinine concentrations were measured in 903 HIV-infected and 287 uninfected women using stored urine from 1999 to 2000, when prevalence of tenofovir use was <1%. Participants were categorized into three categories by level of α1-microglobulin-to-creatinine ratio, and associations with kidney decline and all-cause mortality over 8 years were evaluated.

RESULTS

Urine α1-microglobulin was detectable in 60% of HIV-infected and 40% of uninfected women (P<0.001). Among HIV-infected women, there were 177 (22%), 61 (7%), and 128 (14%) patients with incident CKD, with 10% annual eGFR decline, and who died, respectively. Compared with HIV-infected women in the lowest α1-microglobulin category, HIV-infected women in the highest α1-microglobulin category had a 2.1-fold risk of incident CKD (95% confidence interval, 1.3 to 3.4), 2.7-fold risk of 10% annual eGFR decline (95% confidence interval, 1.2 to 5.9), and 1.6-fold mortality risk (95% confidence interval, 1.0 to 2.6) in models adjusting for kidney risk factors, baseline eGFR, and albuminuria. Among uninfected women, the highest α1-microglobulin category was associated with 3% (relative risk, 2.2; 95% confidence interval, 1.4 to 3.5) and 5% (relative risk, 2.2; 95% confidence interval, 1.1 to 4.3) annual eGFR decline relative to the lowest α1-microglobulin category.

CONCLUSIONS

Proximal tubular dysfunction, indicated by urine α1-microglobulin, was independently associated with kidney function decline in HIV-infected and uninfected women and mortality risk among HIV-infected women.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

High prevalence of signs of renal damage despite normal renal function in a cohort of HIV-infected patients: evaluation of associated factors

Renal disorders are an emerging problem in HIV-infected patients. We performed a cross-sectional study of the first 1000 HIV-infected patients attended at our HIV unit who agreed to participate. We determined the frequency of renal alterations and its related risk factors. Summary statistics and logistic regression were applied. The study sample comprised 970 patients with complete data. Most were white (94%) and men (76%). Median (IQR) age was 48 (42-53) years. Hypertension was diagnosed in 19%, dyslipidemia in 27%, and diabetes mellitus in 3%. According to the Chronic Kidney Disease Epidemiology Collaboration (CKD EPI) equation, 29 patients (3%) had an eGFR<60 ml/min/1.73 m(2); 18 of them (62%) presented altered albumin/creatinine and protein/creatinine (UPC or UAC) ratios. Of the patients with eGFR>60 mL/min, it was present in 293 (30%), 38 of whom (7.1%) had UPC>300 mg/g. Increased risk of renal abnormalities was correlated with hypertension (OR, 1.821 [95%CI, 1.292;2.564]; p=0.001), age (OR, 1.015 [95%CI, 1.001;1.030], per one year; p=0.040), and use of tenofovir disoproxil fumarate (TDF) plus protease inhibitor (PI), (OR, 1.401 [95%CI, 1.078;1.821]; p=0.012). Current CD4 cell count was a protective factor (OR, 0.9995 [95%CI, 0.9991;0.9999], per one cell; p=0.035). A considerable proportion of patients presented altered UPC or UAC ratios, despite having an eGFR>60 mL/min. CD4 cell count was a protective factor; age, hypertension, and use of TDF plus PIs were risk factors for renal abnormalities. Based on our results, screen of renal abnormalities should be considered in all HIV-infected patients to detect these alterations early.

The association of adiposity with kidney function decline among HIV-infected adults: findings from the Fat Redistribution and Metabolic Changes in HIV Infection (FRAM) study

OBJECTIVES

The aim of the study was to investigate the association of adiposity with longitudinal kidney function change in 544 HIV-infected persons in the Study of Fat Redistribution and Metabolic Change in HIV infection (FRAM) cohort over 5 years of follow-up.

METHODS

The regional distribution of muscle and adipose tissue was quantified by whole-body magnetic resonance imaging (MRI), and total adiponectin and leptin levels were measured in serum. Kidney function was assessed using the estimated glomerular filtration rate from serum cystatin C (eGFRCys), obtained at baseline and follow-up. Rapid kidney function decline was defined as annual loss of eGFRCys ≥ 3 mL/min/1.73 m(2) , and incident chronic kidney disease (CKD) was defined as eGFRCys <60 mL/min/1.73 m(2) . Multivariate regression analysis was adjusted for age, race, gender, glucose, antihypertensive use, serum albumin, baseline and change in HIV viral load.

RESULTS

At baseline, mean age was 43 years, mean eGFRCys was 86 mL/min/1.73 m(2) , and 21% of patients had albuminuria. The mean (± standard deviation) eGFRCys decline was -0.11 ± 4.87 mL/min/1.73 m(2) per year; 23% of participants had rapid kidney function decline, and 10% developed incident CKD. The lowest tertile of visceral adipose tissue and the highest tertile of adiponectin were both marginally associated with annual kidney function decline of -0.5 mL/min/1.73 m(2) each, but these associations were not statistically significant after adjustment. We found no statistically significant associations of MRI-measured regional adiposity or serum adipokines with rapid kidney function decline or incident CKD (all P-values>0.1 in adjusted models).

CONCLUSIONS

Contrary to findings in the general population, adiposity did not have a substantial association with longitudinal change in kidney function among HIV-infected persons.

Changes in proteinuria and albuminuria with initiation of antiretroviral therapy: data from a randomized trial comparing tenofovir disoproxil fumarate/emtricitabine versus abacavir/lamivudine

BACKGROUND

Antiretroviral therapy (ART) is associated with improved kidney function; however, the nucleotide reverse transcriptase inhibitor (NRTI) tenofovir disoproxil fumarate (TDF) has been associated with decreased kidney function and proteinuria.

METHODS

We examined changes in urine protein:creatinine (UPCR) and urine albumin:creatinine (UACR) ratios in 245 ART-naive participants in A5202 randomized in a substudy to blinded NRTI (abacavir/lamivudine, ABC/3TC, n = 124 or TDF/emtricitabine, TDF/FTC, n = 121) with open-label protease inhibitor (PI) atazanavir/ritonavir or nonnucleoside reverse transcriptase inhibitor (NNRTI) efavirenz.

RESULTS

At baseline, 18% of participants had clinically significant proteinuria (UPCR ≥200 mg/g), and 11% had clinically significant albuminuria (UACR ≥30 mg/g). The prevalence of clinically significant proteinuria and albuminuria decreased from baseline to week 96 in all treatment groups. In intention-to-treat analyses, there was a significant effect of NRTI component on fold change in UPCR (P = 0.011) and UACR (P = 0.018) from baseline to week 96, with greater improvements in participants randomized to ABC/3TC. There was no significant effect of NNRTI/PI component on fold change in UPCR (P = 0.23) or UACR (P = 0.88), and no significant interactions between NRTI and NNRTI/PI components.

CONCLUSIONS

In this prespecified secondary analysis, ART initiation was associated with improvements in proteinuria and albuminuria, with significantly greater improvements in participants randomized to ABC/3TC versus TDF/FTC. These are the first data from a randomized trial to suggest that initiation of TDF/FTC may not be associated with the same degree of improvement in proteinuria and albuminuria that have been reported with other regimens. Future studies should consider the long-term clinical significance of these findings.

Comparison of renal changes with lopinavir/ritonavir plus raltegravir or tenofovir/emtricitabine in the PROGRESS study

ABSTRACT 

Aim: To assess renal function changes among 172 treatment-naive subjects treated with lopinavir/ritonavir (LPV/r) plus raltegravir (RAL) or LPV/r plus tenofovir/emtricitabine in the PROGRESS study, a prospective, randomized controlled trial. Patients & methods: Serum creatinine, creatinine clearance and chronic kidney disease category were compared between groups. Results: Mean change from baseline to week 96 in creatinine clearance was smaller with LPV/r plus RAL versus LPV/r plus tenofovir/emtricitabine (-1.4 vs -7.3 ml/min; p = 0.035). Chronic kidney disease category improvement was more frequent and the mean increase in serum creatinine was smaller for the LPV/r plus RAL group. Differences in estimated renal function were also detected when the analysis was performed according to baseline demographics. Conclusion: Smaller renal function declines were observed with LPV/r plus RAL. The results from this study warrant further evaluation of the renal safety profile of nucleotide reverse transcriptase inhibitor-sparing regimens.

Low-grade proteinuria is highly prevalent in HIV-positive patients on antiretroviral treatment

OBJECTIVES

HIV-positive patients are at an increased risk for chronic kidney disease. However, these data mainly derive from cohorts with a high percentage of African-American patients, representing a specific ethnical risk group for chronic kidney disease. The aim of this study was to estimate the prevalence and risk factors specifically for early signs of kidney dysfunction in a large, predominantly white cohort of HIV patients.

DESIGN

Cross-sectional study.

METHODS

Prevalence of low-grade proteinuria was measured by quantitative analysis of urinary protein-to-creatinine ratio (cutoff >70 mg/g) and further differentiated by assessing α1-microglobulin (tubular proteinuria) and albumin-to-creatinine ratio (glomerular proteinuria) of HIV patients attending the University Hospital in Cologne, Germany. Together with standard and HIV-related laboratory findings and medical history, risk factors for each form of proteinuria were identified using multivariate forward selection.

RESULTS

Of 945 enrolled patients, 55% were identified with low-grade proteinuria, 41% with tubular proteinuria, and 20% with glomerular proteinuria. Older age was a risk factor for all forms of proteinuria in multivariate analysis. Low-grade proteinuria was also associated with concomitant diabetes and exposure to nucleoside reverse transcriptase inhibitor [anytime during HIV infection, not tenofovir (TDF)-specific], whereas tubular proteinuria was linked to current and any exposure to nucleoside reverse transcriptase inhibitor (TDF-specific). Further risk factors for glomerular proteinuria were hypertension and diabetes in this cohort.

CONCLUSION

Low-grade, glomerular and tubular proteinuria are highly prevalent in this large white HIV cohort. Older age represents a nonmodifiable risk factor for all forms of proteinuria. Glomerular proteinuria is associated with modifiable cardiovascular, but not HIV-related risk factors, whereas tubular proteinuria is linked to TDF exposure.