Association of tenofovir exposure with kidney disease risk in HIV infection

Antiretroviral-treated HIV-infected women have similar long-term kidney function trajectories as HIV-uninfected women

Natural history studies suggest increased risk for kidney function decline with HIV infection, but few studies have made comparisons with HIV-uninfected women. We examined whether HIV infection treated with highly active antiretroviral therapy (HAART) remains associated with faster kidney function decline in the Women's Interagency HIV Study. HIV-infected women initiating HAART with (n=105) or without (n=373) tenofovir (TDF) were matched to HIV-uninfected women on calendar and length of follow-up, age, systolic blood pressure, hepatitis C antibody serostatus, and diabetes history. Linear mixed models were used to evaluate differences in annual estimated glomerular filtration rate (eGFR). Person-visits were 4,741 and 11,512 for the TDF-treated and non-TDF-treated analyses, respectively. Mean baseline eGFRs were higher among women initiated on TDF-containing HAART and lower among those on TDF-sparing HAART compared to their respective HIV-uninfected matches (p<0.05 for both). HIV-infected women had annual rates of eGFR changes similar to HIV-uninfected matches (p-interaction >0.05 for both). Adjusting for baseline eGFR, mean eGFRs at 1 and 3 years of follow-up among women initiated on TDF-containing HAART were lower than their uninfected matches (-4.98 and -4.26 ml/min/1.73 m(2), respectively; p<0.05 for both). Mean eGFR of women initiated on TDF-sparing HAART was lower versus uninfected matches at 5 years (-2.19 ml/min/1.73 m(2), p=0.03). HAART-treated HIV-infected women had lower mean eGFRs at follow-up but experienced rates of annual eGFR decline similar to HIV-uninfected women. Tenofovir use in HIV-infected women with normal kidney function did not accelerate long-term kidney function decline relative to HIV-uninfected women.

Tenofovir treatment duration predicts proteinuria in a multiethnic United States Cohort of children and adolescents with perinatal HIV-1 infection

BACKGROUND

Tenofovir is associated with renal proximal tubule injury. Such toxicity has not been extensively studied in HIV-1-infected children, in whom tenofovir is increasingly used.

METHODS

History, urine and blood were collected at regular intervals from 448 children and adolescents with perinatal HIV-1 infection followed in the Pediatric HIV/AIDS Cohort study. Relationships between tenofovir use and proteinuria and chronic kidney disease (CKD) outcomes were examined using multivariable logistic regression models. Proteinuria was defined as at least one urine protein/creatinine ratio (uPCR) ≥ 0.2, and CKD as ≥ 2 sequential uPCR ≥ 0.2 or estimated glomerular filtration rates <60 mL/min/1.73 m with no subsequent resolution, or a clinical diagnosis not contradicted by a normal uPCR. Subjects with ≥ 2 uPCR <0.2, and no abnormal uPCR and eGFR comprised the comparison group.

RESULTS

Subjects were 47% male, 72% black, 24% Hispanic, with entry mean age (± standard deviation) of 11.5 ± 2.5 years. Proteinuria prevalence at entry, and annually during 3 years, ranged from 10.3% to 13.7%. The cumulative prevalence of proteinuria was 22% (94/434, 95% confidence interval: 18%-26%) and CKD 4.5% (20/448, 95% confidence interval: 2.7%-6.8%). Duration of tenofovir use was an independent predictor of proteinuria, with >3 years of exposure having the highest risk compared with no exposure (odds ratio: 2.53, 95% confidence interval: 1.23-5.22, overall P = 0.01). Overall, duration of tenofovir use did not significantly predict the presence of CKD.

CONCLUSIONS

Rates of proteinuria and CKD were lower than those seen in the pre-highly active antiretroviral therapy era. However, prolonged exposure to tenofovir increases risk of renal injury.

Association between antiretroviral exposure and renal impairment among HIV-positive persons with normal baseline renal function: the D:A:D study

BACKGROUND

Several antiretroviral agents (ARVs) are associated with chronic renal impairment, but the extent of such adverse events among human immunodeficiency virus (HIV)-positive persons with initially normal renal function is unknown.

METHODS

D:A:D study participants with an estimated glomerular filtration rate (eGFR) of ≥ 90 mL/min after 1 January 2004 were followed until they had a confirmed eGFR of ≤ 70 mL/min (the threshold below which we hypothesized that renal interventions may begin to occur) or ≤ 60 mL/min (a value indicative of moderately severe chronic kidney disease [CKD]) or until the last eGFR measurement during follow-up. An eGFR was considered confirmed if it was detected at 2 consecutive measurements ≥ 3 months apart. Predictors and eGFR-related ARV discontinuations were identified using Poisson regression.

RESULTS

Of 22 603 persons, 468 (2.1%) experienced a confirmed eGFR of ≤ 70 mL/min (incidence rate, 4.78 cases/1000 person-years of follow-up [95% confidence interval {CI}, 4.35-5.22]) and 131 (0.6%) experienced CKD (incidence rate, 1.33 cases/1000 person-years of follow-up [95% CI, 1.10-1.56]) during a median follow-up duration of 4.5 years (interquartile range [IQR], 2.7-6.1 years). A current eGFR of 60-70 mL/min caused significantly higher rates of discontinuation of tenofovir (adjusted incidence rate ratio [aIRR], 1.72 [95% CI, 1.38-2.14]) but not other ARVs compared with a current eGFR of ≥ 90 mL/min. Cumulative tenofovir use (aIRR, 1.18/year [95% CI, 1.12-1.25]) and ritonavir-boosted atazanavir use (aIRR, 1.19/year [95% CI, 1.09-1.32]) were independent predictors of a confirmed eGFR of ≤ 70 but were not significant predictors of CKD whereas ritonavir-boosted lopinavir use was a significant predictor for both end points (aIRR, 1.11/year [95% CI, 1.05-1.17] and 1.22/year [95% CI, 1.16-1.28], respectively). Associations were unaffected by censoring for concomitant ARV use but diminished after discontinuation of these ARVs.

CONCLUSIONS

Tenofovir, ritonavir-boosted atazanavir, and ritonavir-boosted lopinavir use were independent predictors of chronic renal impairment in HIV-positive persons without preexisting renal impairment. Increased tenofovir discontinuation rates with decreasing eGFR may have prevented further deteriorations. After discontinuation, the ARV-associated incidence rates decreased.

Tenofovir plasma concentrations according to companion drugs: a cross-sectional study of HIV-positive patients with normal renal function

As the risk of tenofovir-associated renal toxicity has been found to be proportional to the drug plasma concentration, our aim was to measure the determinants of tenofovir plasma exposure in HIV-positive patients with normal renal function. A cross-sectional analysis was conducted in HIV-positive patients chronically receiving tenofovir-containing highly active antiretroviral therapies (HAARTs). Patients on tenofovir-containing antiretroviral regimens, presenting 22 to 26 h after drug intake, having estimated glomerular filtration rates above 60 ml/min, reporting high adherence to antiretroviral medications (above 95% of the doses), and signing a written informed consent were included. Plasma tenofovir concentrations were measured through a validated high-performance liquid chromatography-mass spectrometry (HPLC/LC-MS) method. The tenofovir trough concentrations in 195 patients (median, 50 ng/ml, and interquartile range, 35 to 77 ng/ml) were significantly associated with the estimated glomerular filtration rate, body mass index, and third-drug class (protease-containing versus protease-sparing regimens) (with the highest exposure in unboosted-atazanavir recipients). The results of multivariate analysis showed that the third-drug class and the weight/creatinine ratio were independent predictors of tenofovir trough concentrations. This cross-sectional study shows that tenofovir trough concentrations are predicted by the weight/creatinine ratio and by the coadministered antiretrovirals, with protease inhibitors (whether boosted or unboosted) being associated with the highest plasma exposure. These data, previously available in healthy subjects or for some drugs only, could be useful for designing strategies to manage tenofovir-associated toxicity, since this toxicity has been reported to be dose dependent.

Urinary markers of kidney injury and kidney function decline in HIV-infected women

OBJECTIVE

HIV-infected persons have substantially higher risk of kidney failure than persons without HIV, but serum creatinine levels are insensitive for detecting declining kidney function. We hypothesized that urine markers of kidney injury would be associated with declining kidney function among HIV-infected women.

METHODS

In the Women's Interagency HIV Study, we measured concentrations of albumin-to-creatinine ratio, interleukin-18 (IL-18), kidney injury marker-1 (KIM-1), and neutrophil gelatinase-associated lipocalin from stored urine among 908 HIV-infected and 289 HIV-uninfected participants. Primary analyses used cystatin C-based estimated glomerular filtration rate (CKD-EPI eGFRcys) as the outcome, measured at baseline and 2 follow-up visits over 8 years; secondary analyses used creatinine (CKD-EPI eGFRcr). Each urine biomarker was categorized into tertiles, and kidney decline was modeled with both continuous and dichotomized outcomes.

RESULTS

Compared with the lowest tertiles, the highest tertiles of albumin-to-creatinine ratio (-0.15 mL/min per 1.73 m, P < 0.0001), IL-18 (-0.09 mL/min per 1.73 m, P < 0.0001) and KIM-1 (-0.06 mL/min per 1.73 m, P < 0.001) were independently associated with faster eGFRcys decline after multivariate adjustment including all 3 biomarkers among HIV-infected women. Among these biomarkers, only IL-18 was associated with each dichotomized eGFRcys outcome: ≥3% (relative risk = 1.40; 95% confidence interval: 1.04 to 1.89); ≥5% (1.88; 1.30 to 2.71); and ≥10% (2.16; 1.20 to 3.88) for the highest versus lowest tertile. In alternative models using eGFRcr, the high tertile of KIM-1 had independent associations with 5% (1.71; 1.25 to 2.33) and 10% (1.78; 1.07 to 2.96) decline, and the high IL-18 tertile with 10% decline (1.97; 1.00 to 3.87).

CONCLUSIONS

Among HIV-infected women in the Women's Interagency HIV Study cohort, novel urine markers of kidney injury detect risk for subsequent declines in kidney function.

Tenofovir-associated proteinuria

Proteinuria was observed in 27% of 153 patients taking tenofovir for more than 1 year. Concomitant protease inhibitor therapy and cumulative tenofovir exposure were independently associated with proteinuria in this cohort. Proteinuria was reversible in 11 of 12 patients who ceased tenofovir because of proteinuria without altering other medications. Clinicians should be aware that tenofovir can cause reversible proteinuria in patients with HIV.

Meta-analysis of the safety, tolerability, and efficacy of lopinavir/ritonavir-containing antiretroviral therapy in HIV-1-infected women

PURPOSE

Women comprise ≯50% of HIV-infected patients, yet safety, tolerability, and efficacy data in women taking antiretrovirals (ARVs) are limited. Lopinavir/ ritonavir (LPV/r)-anchored regimens are globally the most widely prescribed HIV-1 protease inhibitor regimens. The objective was to investigate the safety and efficacy of LPV/r-based therapy in women.

METHODS

A database query yielded all available data in HIV-1-infected subjects receiving LPV/r-based triple-ARV regimens from randomized clinical trials lasting ≥48 weeks from Abbott or Abbott-supported AIDS Clinical Trials Group studies. Efficacy (HIV-1 RNA levels, CD4+ T-cell counts) and safety and tolerability (treatment discontinuation, treatment-related adverse events [AE], and clinical laboratory abnormalities) at 48 weeks were assessed for total women, women by age (≥50, <50 years) and body mass index (BMI; <25, ≥25 to <30, ≥30 kg/m2), and sex.

RESULTS

Nine hundred ninety-two women initiated LPV/r-based therapy (of whom 79.2% were ARV-naïve), with 83.6% completing 48 weeks of treatment. There were 75.5% of women who achieved a threshold of HIV RNA <400 copies/mL by intent-to-treat, non-completer equals failure (ITT, NC = F) analysis, with a mean ± SE CD4+ T-cell count increase of 191.6 ± 4.92 cells/mm3 from baseline. Women aged ≥50 versus <50 years had higher incidence of moderate-to-severe treatment-related AEs and certain laboratory abnormalities, better virologic response (HIV RNA <400 copies/mL by ITT, NC = F), similar immunologic responses, and similar overall incidence of treatment discontinuations. Higher incidences of certain moderate-to-severe treatment-related AEs and laboratory abnormalities occurred in women with BMI ≥30 kg/m2; however, no effect of BMI on efficacy or discontinuation was observed.

CONCLUSIONS

LPV/r-based regimens were efficacious and well-tolerated in women without marked differences based on age and BMI categories evaluated.

Performance of creatinine and cystatin C GFR estimating equations in an HIV-positive population on antiretrovirals

OBJECTIVE

To evaluate the performance of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine, cystatin C, and creatinine-cystatin C estimating equations in HIV-positive patients.

METHODS

We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) Study and CKD-EPI creatinine 2009, CKD-EPI cystatin C 2012, and CKD-EPI creatinine-cystatin C 2012 glomerular filtration rate (GFR) estimating equations compared with GFR measured using plasma clearance of iohexol in 200 HIV-positive patients on stable antiretroviral therapy. Creatinine and cystatin C assays were standardized to certified reference materials.

RESULTS

Of the 200 participants, median (IQR) CD4 count was 536 (421) and 61% had an undetectable HIV viral load. Mean (SD) measured GFR (mGFR) was 87 (26) mL/min per 1.73 m. All CKD-EPI equations performed better than the MDRD Study equation. All 3 CKD-EPI equations had similar bias and precision. The cystatin C equation was not more accurate than the creatinine equation. The creatinine-cystatin C equation was significantly more accurate than the cystatin C equation, and there was a trend toward greater accuracy than the creatinine equation. Accuracy was equal or better in most subgroups with the combined equation compared to either alone.

CONCLUSIONS

The CKD-EPI cystatin C equation does not seem to be more accurate than the CKD-EPI creatinine equation in patients who are HIV-positive, supporting the use of the CKD-EPI creatinine equation for routine clinical care for use in North American populations with HIV. The use of both filtration markers together as a confirmatory test for decreased estimated GFR based on creatinine in individuals who are HIV-positive requires further study.

Triple-combination rilpivirine, emtricitabine, and tenofovir (Complera™/Eviplera™) in the treatment of HIV infection

The combination rilpivirine (RPV)/emtricitabine (FTC)/tenofovir (TDF) is a once-daily, single-tablet regimen (STR) containing one nonnucleoside reverse-transcriptase inhibitor associated with two nucleos(t)ide reverse transcriptase inhibitors. It is approved by regulatory agencies (eg, US Food and Drug Association, European Medicines Agency) in all countries in which it is manufactured, except Switzerland, as first-line highly active antiretroviral therapy (HAART) for the treatment of naïve patients with HIV infection and a viral load HIV-RNA level of ≤100,000 copies/mL. Two large trials (ECHO and THRIVE) comparing RPV with efavirenz, along with different background regimens, led to approval of the drug, while a more recent trial (STaR) explored the use of STR. RPV showed noninferiority to efavirenz in all the studies, including superiority as an STR in patients with HIV-RNA ≤100,000 copies/mL in the STaR study. A positive CD4 cell response was observed in all the studies, both in the RPV and efavirenz groups. The incidence of virologic failures was higher for RPV, but was mostly referred to patients with HIV-RNA >100,000 copies/mL. There were fewer adverse events (AEs) with the RPV-based regimens versus efavirenz-based regimens, with a lower discontinuation rate because of AEs, especially psychiatric-neurological AEs, and a significantly lower rate of blood-lipid abnormalities. In the SPIRIT study (a switch study), significantly greater improvements from baseline in serum total cholesterol, low-density lipoprotein cholesterol, and trygliceride were demonstrated in patients switching to RPV/FTC/TDF from a ritonavir-boosted protease inhibitor (PI/r)-based regimen, than in those who continued treatment with a PI/r regimen. RPV's better tolerability, associated with its once-daily STR formulation, is key to improving patients' adherence and quality of life, which are among the most important factors affecting the therapeutic efficacy of an antiretroviral regimen. In summary, RPV/FTC/TDF STR is a valuable treatment option for the majority of antiretroviral-naïve HIV-infected patients. Furthermore, the use of this STR in the therapeutic switch, like in the SPIRIT study, can result in another valuable option by which to reduce AEs and improve patients' quality of life.

Pharmacists as providers of HIV pre-exposure prophylaxis

The efficacy of HIV pre-exposure prophylaxis (PrEP) has been demonstrated in four clinical trials to date; however, the success of PrEP is largely dependent on high levels of medication adherence. Due to their extensive experience and expertise in medication adherence counseling, as well as their ability to monitor and manage medication adverse effects and drug-drug interactions, clinical pharmacists are well-equipped to play a key role in effective PrEP utilization. Here we discuss reasons favoring the establishment of a protocol-based, pharmacist-run PrEP clinic.

Renal dysfunction in the setting of HIV/AIDS

Antiretroviral therapy has been immensely successful in reducing the incidence of opportunistic infections and death after HIV infection. This has resulted in heightened interest in noninfectious comorbidities including kidney disease. Although HIV-associated nephropathy, the most ominous kidney disease related to the direct effects of HIV, may be prevented and treated with antiretrovirals, kidney disease remains an important issue in this population. In addition to the common risk factors for kidney disease of diabetes mellitus and hypertension, HIV-infected individuals have a high prevalence of other risk factors, including hepatitis C and exposure to antiretrovirals and other medications. Therefore, the differential diagnosis is vast. Early identification (through efficient screening) and prompt treatment of kidney disease in HIV-infected individuals are critical to lead to better outcomes. This review focuses on clinical and epidemiological issues, treatment strategies (including dialysis and kidney transplantation), and recent advances among kidney disease in the HIV population.

Association between tenofovir exposure and reduced kidney function in a cohort of HIV-positive patients: results from 10 years of follow-up

BACKGROUND

Some studies have shown that tenofovir disoproxil fumarate (TDF), a drug widely used in highly active antiretroviral therapy, is associated with kidney dysfunction, but the magnitude of the effect and its clinical impact is still being debated. Our objective was to evaluate the association between long-term TDF exposure and kidney dysfunction in a cohort of 1043 human immunodeficiency virus-positive patients followed up for 10 years and to quantify the loss in estimated glomerular filtration rate (eGFR) in patients exposed to TDF in comparison with those exposed to other antiretroviral therapies.

METHODS

Adjusted hazard ratios (HR) and odds ratios (OR) for the association between TDF and kidney dysfunction (defined as eGFR <90 mL/min/1.73 m(2)) were calculated using the Cox proportional hazards model and generalized estimating equations. Mean loss in eGFR attributable to TDF by cumulative years of exposure was estimated using linear regressions.

RESULTS

Tenofovir exposure increased the risk of kidney dysfunction by 63% (HR, 1.63; 95% confidence interval, 1.26-2.10). The cumulative eGFR loss directly attributable to TDF after 1, 2, 3, and 4 years of TDF exposure was -3.05 (P = .017), -4.05 (P = .000), -2.42 (P = .023), and -3.09 mL/min/1.73 m(2) (P = .119), respectively, which shows that most of the loss occurred during the first years of exposure.

CONCLUSIONS

In this cohort, TDF exposure was associated with reduced kidney function, but the loss in eGFR attributable to TDF is relatively mild in a long-term perspective.

Clinical outcomes of a combined HIV and renal clinic

Background

Renal disease is an emerging problem in patients living with human immunodeficiency virus (HIV), as illustrated by an increased incidence of acute kidney injury and chronic kidney disease (CKD) from HIV, its associated treatment and comorbidities such as diabetes and vascular disease. We have established a combined HIV-renal clinic to manage such patients, enhance their treatment and minimize outpatient visits.

Methods

We have analysed the outcomes of the first 99 patients seen in the clinic using electronic patient records. These ninety-nine patients were referred to the service from HIV physicians in West London and all the patients were seen jointly by an HIV and a renal consultant.

Results

Sixty-five percent of the patients were referred with reduced renal function or proteinuria [mean creatinine at presentation 136 mcmol/L, estimated glomerular filtration rate (eGFR) 57 mL/min/1.73 m²]. The majority (53%) had risk factors predisposing to vascular disease including diabetes, hypertension, previous stroke or myocardial infarction. Overall, 27% of patients had a renal diagnosis directly associated with HIV (HIVAN, immune complex nephritis, tenofovir toxicity, Fanconi syndrome), 73% had an alternative possible cause. Twenty-seven percent of patients had low-level proteinuria (urine protein:creatinine ratio abnormal but <100 mg/mmol) or mildly reduced eGFR (40–66 mL/min/1.73 m²) without a clear underlying cause. Ten percent of patients were thought to have tenofovir-induced renal damage all of whom improved on cessation of this agent. Following the review in the combined clinic, 64% of patients had a change in treatment or management, with 50% improving their renal parameters as a result. Most patients were discharged back to their main HIV teams for ongoing follow-up.

Conclusions

A combined HIV-renal clinic can enhance patient care with reduced outpatient visits.

Risk factors for chronic kidney disease in a large cohort of HIV-1 infected individuals initiating antiretroviral therapy in routine care

OBJECTIVE

To examine long-term effects of antiretroviral therapy (ART) on kidney function, we evaluated the incidence and risk factors for chronic kidney disease (CKD) among ART-naive, HIV-infected adults and compared changes in estimated glomerular filtration rates (eGFR) before and after starting ART.

METHODS

Multicenter observational cohort study of patients with at least one serum creatinine measurement before and after initiating ART. Cox proportional hazard models, and marginal structure models examined CKD risk factors; mixed-effects linear models examined eGFR slopes.

RESULTS

Three thousand, three hundred and twenty-nine patients met entry criteria, contributing 10 099 person-years of observation on ART. ART was associated with a significantly slower rate of eGFR decline (from -2.18 to -1.37 ml/min per 1.73 m per year; P = 0.02). The incidence of CKD defined by eGFR thresholds of 60, 45 and 30 ml/min per 1.73 m was 10.5, 3.4 and 1.6 per 1000 person-years, respectively. In adjusted analyses black race, hepatitis C coinfection, lower time-varying CD4 cell count and higher time-varying viral load on ART were associated with higher CKD risk, and the magnitude of these risks increased with more severe CKD. Tenofovir and a ritonavir-boosted protease inhibitor (rPI) was also associated with higher CKD risk [hazard odds ratio for an eGFR threshold <60 ml/min per 1.73 m: 3.35 (95% confidence interval (CI) = 1.40-8.02)], which developed in 5.7% of patients after 4 years of exposure to this regimen-type.

CONCLUSION

ART was associated with reduced CKD risk in association with CD4 cell restoration and plasma viral load suppression, despite an increased CKD risk that was associated with initial regimens that included tenofovir and rPI.

Incidence of renal toxicity in HIV-infected, antiretroviral-naïve patients starting tenofovir/emtricitabine associated with efavirenz, atazanavir/ritonavir, or lopinavir/ritonavir

OBJECTIVES

We performed a retrospective cohort study of HIV-infected antiretroviral-naïve patients starting a first antiretroviral therapy with tenofovir/emtricitabine plus efavirenz (EFV), atazanavir/ritonavir (ATV/r), or lopinavir/ritonavir (LPV/r).

METHODS

The incidence of renal impairment or proximal tubular dysfunction was evaluated during a 12-month follow-up. Renal impairment was diagnosed by a reduced estimated glomerular filtration rate (eGFR) calculated using the Modification of Diet in Renal Disease (MDRD) formula, and tubular dysfunction was diagnosed when ≥ 2 among proteinuria, glucosuria, hypouricaemia, hypophosphataemia, and hypokalaemia, were identified.

RESULTS

A total of 235 patients were enrolled: 82 taking EFV, 78 ATV/r, and 75 LPV/r. The mean decline in eGFR after the 12-month follow-up was significantly greater in subjects treated with ATV/r (-10.4 ml/min/1.73 m(2)) than in those receiving EFV (- 5.1; p = 0.002) or LPV/r (-4.8; p = 0.003). Similarly, a significantly higher incidence of proximal tubulopathy was observed among ATV/r-treated patients (14.1%) compared with patients receiving EFV (4.9%) or LPV/r (5.3%).

CONCLUSIONS

In our retrospective study, naïve patients receiving tenofovir/emtricitabine and ATV/r for 12 months showed a significantly higher decline in eGFR and a significantly higher incidence of proximal tubulopathy than those receiving tenofovir/emtricitabine plus EFV or LPV/r, even though clinically evident renal toxicity associated with tenofovir-based treatment is a very uncommon event.

The glory of guidelines and the twilight of reality: controversies and challenges in the prevention and treatment of HIV in children

Since the discovery of HIV 30 years ago, we have learned much about HIV in children and adolescents. Dramatic declines have occurred in mother-to-child transmission of HIV in resource-rich countries. Resource-poor countries struggle with improving prevention of mother-to-child transmission due to the lack of universal antiretroviral treatment for pregnant and nursing mothers. In children infected with HIV, pharmacokinetic, safety and efficacy data have been determined for many of the older drugs. Data are lacking for the newer, safer and more effective currently available drugs, resulting in the pediatric guidelines lagging behind adult recommendations. Although guidelines for prevention and treatment are helpful, the way they are created causes them to lag behind new scientific evidence, and in some situations they will be confusing or only based on expert opinion. Improving prevention of HIV infection in adolescents and young adults and in treating those who become HIV infected is crucially important. The next 10 years hold tremendous opportunities for improvements in prevention and treatment of HIV in children, adolescents and young adults.

Antiviral agents and HIV prevention: controversies, conflicts, and consensus

Antiviral agents can be used to prevent HIV transmission before exposure as preexposure prophylaxis (PrEP), after exposure as postexposure prophylaxis, and as treatment of infected people for secondary prevention. Considerable research has shed new light on antiviral agents for PrEP and for prevention of secondary HIV transmission. While promising results have emerged from several PrEP trials, the challenges of poor adherence among HIV-negative clients and possible increase in sexual risk behaviors remain a concern. In addition, a broader pipeline of antiviral agents for PrEP that focuses on genital tract pharmacology and safety and resistance issues must be developed. Antiretroviral drugs have also been used to prevent HIV transmission from HIV-infected patients to their HIV-discordant sexual partners. The HIV Prevention Trials Network 052 trial demonstrated nearly complete prevention of HIV transmission by early treatment of infection, but the generalizability of the results to other risk groups - including intravenous drug users and MSM - has not been determined. Most importantly, the best strategy for use of antiretroviral agents to reduce the spread of HIV at either the individual level or the population level has not been developed, and remains the ultimate goal of this area of investigation.

The kidney in HIV infection: beyond HIV-associated nephropathy

Acute kidney injury (AKI) and chronic kidney disease (CKD) are more common in HIV-infected persons than in the general population. AKI is associated with poor health outcomes, including increased risk of heart failure, cardiovascular events, end-stage renal disease (ESRD), and mortality. The most common causes of AKI in HIV-infected persons are systemic infections and adverse drug effects. The prevalence of CKD is rising in the HIV-infected population and CKD is increasingly likely to be caused by comorbid conditions, such as diabetes and hypertension, that frequently cause CKD in the general population. Guidelines for CKD screening in HIV-infected patients are being revised. It is currently recommended that all patients be screened for creatinine-based estimates of glomerular filtration rate and for urine protein at the time of HIV diagnosis. Annual screening is recommended for high-risk patients. Hemodialysis, peritoneal dialysis, and kidney transplantation are all options for treating ESRD in HIV-infected patients. Hemodialysis and peritoneal dialysis offer similar survival in HIV-infected patients with ESRD. In selected patients with well-controlled HIV infection, kidney transplantation is associated with survival intermediate between that in the overall transplant population and that among transplant recipients older than 65 years. This article summarizes a presentation by Christina M. Wyatt, MD, at the IAS-USA continuing medical education program held in Chicago in May 2012, describing AKI and CKD using case illustrations.

Antiretroviral therapy adherence and drug-drug interactions in the aging HIV population

It is estimated that by 2015 more than half of all HIV-infected individuals in the United States will be 50 years of age or older. As this population ages, the frequency of non-AIDS related comorbidities increases, which includes cardiovascular, metabolic, gastrointestinal, genitourinary and psychiatric disorders. As a result, medical management of the aging HIV population can be complicated by polypharmacy and higher pill burden, leading to poorer antiretroviral therapy (ART) adherence. Adherence to ART is generally better in older populations when compared to younger populations; however, cognitive impairment in elderly patients can impair adherence, leading to worse treatment outcomes. Practical monitoring tools can improve adherence and increase rates of viral load suppression. Several antiretroviral drugs exhibit inhibitory and/or inducing effects on cytochrome P450 isoenzymes, which are responsible for the metabolism of many medications used for the treatment of comorbidities in the aging HIV population. The combination of ART with polypharmacy significantly increases the chance of potentially serious drug-drug interactions (DDIs), which can lead to drug toxicity, poorer ART adherence, loss of efficacy of the coadministered medication, or virologic breakthrough. Increasing clinicians awareness of common DDIs and the use of DDI programs can prevent coadministration of potentially harmful combinations in elderly HIV-infected individuals. Well designed ART adherence interventions and DDI studies are needed in the elderly HIV population.

Patient-reported symptoms on the antiretroviral regimen efavirenz/emtricitabine/tenofovir

Most patients (80-90%) newly diagnosed with HIV are started on the antiretroviral regimen efavirenz, emtricitabine, and tenofovir (EFV/FTC/TDF). Existing studies of patient tolerability, however, are limited. We compared symptom experiences of patients on EFV/FTC/TDF, and the subsequent impact on health-related quality of life, with those of patients on other combination antiretroviral therapy (cART). We conducted a cross-sectional analysis of the Veterans Aging Cohort Study from February 2008 to August 2009 to compare the symptom experiences of patients on EFV/FTC/TDF vs. other cART, unadjusted and then adjusted for treatment characteristics, and comorbid disease severity. We then assessed the association between EFV/FTC/TDF use and health-related quality of life. Among the 1,759 patients in our analytic sample, EFV/FTC/TDF use was associated with fewer symptoms than was other cART. The use of EFV/FTC/TDF was independently associated with health-related quality of life, and this association was at least partially explained by symptom burden.