Estimated glomerular filtration rate, chronic kidney disease and antiretroviral drug use in HIV-positive patients

High prevalence of renal dysfunction and association with risk of death amongst HIV-infected Ghanaians

OBJECTIVES

To determine the prevalence of HIV-associated renal dysfunction (RD), identify risk factors for RD and explore the association between baseline renal function and mortality in an HIV-infected population in Ghana.

METHODS

Creatinine clearance (CrCl) or estimated glomerular filtration rate (eGFR) was calculated in patients attending an HIV clinic between 2004 and 2011 using Cockcroft-Gault, MDRD and CKD-EPI formulae. Logistic regression analysis was used to identify risk factors associated with RD and Kaplan-Meier/Cox proportional regression analyses to explore associations between baseline CrCl/eGFR and subsequent mortality.

RESULTS

In 3137 patients starting antiretroviral therapy (ART) the frequency (95%-CI) of RD, defined by CrCl <60 ml/min/1.73 m(2) using Cockroft-Gault formula was 38.8% (37.1-40.5%). RD prevalence in a sub-population of 238 patients, including proteinuria in the definition, was 15.3% (10.3-22.1%) in ART-treated and 43.6% (34.0-53.7%) in ART-naïve patients. RD at baseline was associated with increasing age, low CD4 counts, advanced WHO stage and female gender. Cox proportional hazard analysis identified an increased hazard of death with decreasing CrCl, HR 1.46 (1.31-1.63) for each tertile lower than CrCl of 90 ml/min/1.73 m(2).

CONCLUSIONS

RD is very common in HIV-infected ART-naïve Ghanaians, and associated with increased risk of mortality. Screening and monitoring of RD is important in this setting, particularly as tenofovir use increases.

Cost-utility analysis of lopinavir/ritonavir versus atazanavir + ritonavir administered as first-line therapy for the treatment of HIV infection in Italy: from randomised trial to real world

Objective

To estimate the lifetime cost utility of two antiretroviral regimens (once-daily atazanavir plus ritonavir [ATV+r] versus twice-daily lopinavir/ritonavir [LPV/r]) in Italian human immunodeficiency virus (HIV)-infected patients naïve to treatment.

Design

With this observational retrospective study we collected the clinical data of a cohort of HIV-infected patients receiving first-line treatment with LPV/r or ATV+r.

Methodology

A Markov microsimulation model including direct costs and health outcomes of first- and second-line highly active retroviral therapy was developed from a third-party (Italian National Healthcare Service) payer’s perspective. Health and monetary outcomes associated with the long-term use of ATV+r and LPV/r regimens were evaluated on the basis of eight health states, incidence of diarrhoea and hyperbilirubinemia, AIDS events, opportunistic infections, coronary heart disease events and, for the first time in an economic evaluation, chronic kidney disease (CKD) events. In order to account for possible deviations between real-life data and randomised controlled trial results, a second control arm (ATV+r 2) was created with differential transition probabilities taken from the literature.

Results

The average survival was 24.061 years for patients receiving LPV/r, 24.081 and 24.084 for those receiving ATV+r 1 and 2 respectively. The mean quality-adjusted life-years (QALYs) were higher for the patients receiving LPV/r than those receiving ATV+r (13.322 vs. 13.060 and 13.261 for ATV+r 1 and 2). The cost-utility values were 15,310.56 for LPV/r, 15,902.99 and 15,524.85 for ATV+r 1 and 2.

Conclusions

Using real-life data, the model produced significantly different results compared with other studies. With the innovative addition of an evaluation of CKD events, the model showed a cost-utility value advantage for twice-daily LPV/r over once-daily ATV+r, thus providing evidence for its continued use in the treatment of HIV.

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.

Lopinavir/ritonavir combined with raltegravir or tenofovir/emtricitabine in antiretroviral-naive subjects: 96-week results of the PROGRESS study

Alternative combinations of antiretrovirals (ARVs) are desired to increase treatment options for HIV-infected patients. PROGRESS was a randomized, open-label, 96-week pilot study comparing a regimen of lopinavir/ritonavir (LPV/r) 400/100 mg twice daily in combination with either raltegravir (RAL) 400 mg twice daily or tenofovir/emtricitabine (TDF/FTC) 300/200 mg once daily in ARV-naive adults. A total of 206 subjects were randomized and treated (LPV/r+RAL, N=101; LPV/r+TDF/FTC, N=105). Demographics and baseline characteristics were similar across treatment groups. At 96 weeks, 66.3% of subjects receiving LPV/r+RAL and 68.6% of subjects receiving LPV/r+TDF/FTC were responders (plasma HIV-1 RNA levels<40 copies/ml) by the FDA time to loss of virologic response (FDA-TLOVR) algorithm (p=0.767). Mean CD4(+) T cell increases through 96 weeks were similar between treatment groups (LPV/r+RAL=281 cells/mm(3), LPV/r+TDF/FTC=296 cells/mm(3), p=0.598). Safety and tolerability were generally similar between groups. The LPV/r+RAL regimen resulted in greater increases in peripheral fat, but not trunk fat, compared with LPV/r+TDF/FTC. There was a statistically significantly greater mean reduction in estimated glomerular filtration rate from baseline to week 96 in the LPV/r+TDF/FTC group compared with the LPV/r+RAL group (-7.33 ml/min vs. -1.43 ml/min; p=0.035). The LPV/r+TDF/FTC group had a statistically significant (p<0.001) mean percent decrease from baseline to week 96 in bone mineral density, which was significantly different from the mean percent change in the LPV/r+RAL group (-2.48% vs. +0.68%, p<0.001). These efficacy and safety observations support further evaluation of the LPV/r+RAL regimen.

Abacavir/lamivudine versus tenofovir/emtricitabine in virologically suppressed patients switching from ritonavir-boosted protease inhibitors to raltegravir

There are few clinical data on the combination abacavir/lamivudine plus raltegravir. We compared the outcomes of patients from the SPIRAL trial receiving either abacavir/lamivudine or tenofovir/emtricitabine at baseline who had taken at least one dose of either raltegravir or ritonavir-boosted protease inhibitors. For the purpose of this analysis, treatment failure was defined as virological failure (confirmed HIV-1 RNA ≥50 copies/ml) or discontinuation of abacavir/lamivudine or tenofovir/emtricitabine because of adverse events, consent withdrawal, or lost to follow-up. There were 143 (72.59%) patients with tenofovir/emtricitabine and 54 (27.41%) with abacavir/lamivudine. In the raltegravir group, there were three (11.11%) treatment failures with abacavir/lamivudine and eight (10.96%) with tenofovir/emtricitabine (estimated difference 0.15%; 95% CI -17.90 to 11.6). In the ritonavir-boosted protease inhibitor group, there were four (14.81%) treatment failures with abacavir/lamivudine and 12 (17.14%) with tenofovir/emtricitabine (estimated difference -2.33%; 95% CI -16.10 to 16.70). Triglycerides decreased and HDL cholesterol increased through the study more pronouncedly with abacavir/lamivudine than with tenofovir/emtricitabine and differences in the total-to-HDL cholesterol ratio between both combinations of nucleoside reverse transcriptase inhibitors (NRTIs) tended to be higher in the raltegravir group, although differences at 48 weeks were not significant. While no patient discontinued abacavir/lamivudine due to adverse events, four (2.80%) patients (all in the ritonavir-boosted protease inhibitor group) discontinued tenofovir/emtricitabine because of adverse events (p=0.2744). The results of this analysis do not suggest that outcomes of abacavir/lamivudine are worse than those of tenofovir/emtricitabine when combined with raltegravir in virologically suppressed HIV-infected adults.

Risk, predictors, and mortality associated with non-AIDS events in newly diagnosed HIV-infected patients: role of antiretroviral therapy

OBJECTIVE

We aimed to characterize non-AIDS events (NAEs) occurring in newly diagnosed HIV-infected patients in a contemporary cohort.

METHODS

The Cohort of the AIDS Research Network (CoRIS) is a prospective, multicenter cohort of HIV-infected adults antiretroviral naive at entry, established in 2004. We evaluated the incidence of and the mortality due to NAEs and AIDS events through October 2010. Poisson regression was used to investigate factors associated with a higher incidence of NAEs.

RESULTS

Overall, 5185 patients (13.306 person-years of follow-up), median age (interquartile range) 36 (29-43) years, participated in the study. A total of 86.5% patients had been diagnosed in 2004 or later. The incidence rate of NAEs was 28.93 per 1000 person-years [95% confidence interval (CI) 26.15-32.07], and of AIDS-defining events 25.23 per 1000 person-years (95% CI 22.60-28.16). The most common NAEs were psychiatric, hepatic, malignant, renal, and cardiovascular related. After adjustment, age, higher HIV-viral load, and lower CD4 cell count at cohort entry were associated with the occurrence of NAEs, whereas likelihood significantly decreased with sexual transmission and higher educational level. Additionally, antiretroviral therapy was inversely associated with the development of some NAEs, specifically of psychiatric [incidence rate ratio (95% CI) 0.54 (0.30-0.96)] and renal-related [incidence rate ratio (95% CI) 0.31 (0.13-0.72)] events. One hundred and seventy-three (3.33%) patients died during the study period. NAEs contributed to 28.9% of all deaths, with an incidence rate (95% CI) of 3.75 (2.84-4.94) per 1000 person-years.

CONCLUSION

In patients newly diagnosed with HIV infection, NAEs are a significant cause of morbidity and mortality. Our results suggest a protective effect of antiretroviral therapy in the occurrence of NAEs, in particular of psychiatric and renal-related events.

Diabetes and Hypertension among Patients Receiving Antiretroviral Treatment Since 1998 in Senegal: Prevalence and Associated Factors

Cardiovascular risk factors in people on antiretroviral treatment (ART) are poorly documented in resource-constrained settings. A cross-sectional study was conducted in 2009 to assess prevalence of diabetes and hypertension in a sample of 242 HIV-infected patients who had initiated ART between 1998 and 2002 in Dakar, Senegal (ANRS 1215 observational cohort). World Health Organization (WHO) criteria were applied to diagnose diabetes and hypertension. Multiple logistic regressions were used to identify factors associated with diabetes and hypertension. Patients had a median age of 46 years and had received ART for a median duration of about 9 years. 14.5% had diabetes and 28.1% had hypertension. Long duration of ART (≥119 months), older age, higher body mass index (BMI), and higher levels of total cholesterol were associated with higher risks of diabetes. Older age, higher BMI at ART initiation, and higher levels of triglycerides were associated with higher risk of hypertension. This study shows that diabetes and hypertension were frequent in these Senegalese HIV patients on ART. It confirms the association between duration of ART and diabetes and highlights the need to implement programs for prevention of cardiovascular risk factors in HIV patients from resource-constrained settings.

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.

Kidney Disease in HIV-Infected Persons

Kidney disease is more prevalent among persons living with HIV, and may arise from a combination of comorbidities, co-infections, and medication-associated toxicities. Additional effects of HIV-1 viral replication, immunodeficiency and genetic factors also contribute to kidney disease. As is true in the general population, persons of African descent exhibit a disproportionate risk for severe kidney disease. Antiretroviral therapy (ART) modifies the natural history of HIV-associated nephropathy (HIVAN), and renal benefits of ART may not be limited to persons with HIVAN. Robust associations between proteinuria and cardiovascular disease imply that common mechanisms of vascular endothelial dysfunction may contribute to both processes.

Metabolic effects of darunavir/ritonavir versus atazanavir/ritonavir in treatment-naive, HIV type 1-infected subjects over 48 weeks

We assessed metabolic changes for darunavir/ritonavir (DRV/r) once daily (qd) versus atazanavir/ritonavir (ATV/r) qd with fixed-dose tenofovir/emtricitabine. This was a phase 4, multicenter, open-label, randomized exploratory study. Treatment-naive, HIV-1-infected adults received DRV/r 800/100 mg qd or ATV/r 300/100 mg qd, both with emtricitabine/tenofovir 200/300 mg qd. Primary end point: change in triglyceride levels from baseline to week 12. Secondary end points: week 12 and week 48 changes in lipid parameters, insulin sensitivity, inflammatory/coagulation/bacterial translocation biomarkers, viral load, CD4(+) cell count, and week 48 changes in adipose tissue distribution and subjects' perceptions of body changes. In the DRV/r arm, 32/34 and 29/34 subjects completed weeks 12 and 48, respectively; in the ATV/r arm, 30/31 and 25/31 subjects completed weeks 12 and 48, respectively. Small changes in lipid parameters from baseline to weeks 12 and 48 were observed in both arms. Differences were noted between arms in mean changes in total cholesterol (DRV/r, 20.3 mg/dl; ATV/r, 4.6 mg/dl) and apolipoprotein A1 (DRV/r, 10.7 mg/dl; ATV/r, -0.7 mg/dl) at week 12. At week 48, no clinically relevant differences between arms were noted for changes in any lipid parameter, fasting glucose, or insulin sensitivity. Biomarkers generally decreased and efficacy parameters improved in both arms over 48 weeks. Changes in adipose tissue were small and comparable between arms. Subjects' perceptions of body changes generally improved in both study arms. This first pilot comparison in HIV-1-infected subjects suggests that DRV/r has a metabolic profile similar to ATV/r over 48 weeks of treatment. Further randomized studies are warranted.

Accelerated Aging in HIV Patients

Life expectancy has been increasing in the last few decades in the Western world and is accompanied by higher occurrence of age-related diseases like metabolic, cardiovascular, and renal diseases and also with a decline in immune functions. In HIV-infected people, due to the use of combination antiretroviral therapy (cART), life expectancy has increased. As a result, non-AIDS conditions which are age-associated have become more prevalent and appear earlier, resulting in accelerated aging in HIV patients. These non-AIDS conditions in HIV patients are associated with CD4+ T cell counts: lower counts are associated with higher rates of liver, cardiovascular, renal, and neurocognitive disorders. The effect of viral load and cART on the earlier occurrence of age-associated diseases is less significant than the CD4 count effect. Thus, the loss of immune functions in HIV-infected patients may enhance aging.

Baseline kidney function as predictor of mortality and kidney disease progression in HIV-positive patients

BACKGROUND

Chronic kidney disease (CKD) is associated with increased all-cause mortality and kidney disease progression. Decreased kidney function at baseline may identify human immunodeficiency virus (HIV)-positive patients at increased risk of death and kidney disease progression.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

7 large HIV cohorts in the United Kingdom with kidney function data available for 20,132 patients.

PREDICTOR

Baseline estimated glomerular filtration rate (eGFR).

OUTCOMES

Death and progression to stages 4-5 CKD (eGFR <30 mL/min/1.73 m(2) for >3 months) in Cox proportional hazards and competing-risk regression models.

RESULTS

Median age at baseline was 34 (25th-75th percentile, 30-40) years, median CD4 cell count was 350 (25th-75th percentile, 208-520) cells/μL, and median eGFR was 100 (25th-75th percentile, 87-112) mL/min/1.73 m(2). Patients were followed up for a median of 5.3 (25th-75th percentile, 2.0-8.9) years, during which 1,820 died and 56 progressed to stages 4-5 CKD. A U-shaped relationship between baseline eGFR and mortality was observed. After adjustment for potential confounders, eGFRs <45 and >105 mL/min/1.73 m(2) remained associated significantly with increased risk of death. Baseline eGFR <90 mL/min/1.73 m(2) was associated with increased risk of kidney disease progression, with the highest incidence rates of stages 4-5 CKD (>3 events/100 person-years) observed in black patients with eGFR of 30-59 mL/min/1.73 m(2) and those of white/other ethnicity with eGFR of 30-44 mL/min/1.73 m(2).

LIMITATIONS

The relatively small numbers of patients with decreased eGFR at baseline and low rates of progression to stages 4-5 CKD and lack of data for diabetes, hypertension, and proteinuria.

CONCLUSIONS

Although stages 4-5 CKD were uncommon in this cohort, baseline eGFR allowed the identification of patients at increased risk of death and at greatest risk of kidney disease progression.

Hepatitis C virus viremia increases the incidence of chronic kidney disease in HIV-infected patients

BACKGROUND

Several studies have reported on an association between hepatitis C virus (HCV) antibody status and the development of chronic kidney disease (CKD), but the role of HCV viremia and genotype are not well defined.

METHODS

Patients with at least three serum creatinine measurements after 1 January 2004 and known HCV antibody status were included. Baseline was defined as the first eligible estimated glomerular filtration rate (eGFR) (Cockcroft-Gault equation), and CKD was either a confirmed (>3 months apart) eGFR of 60 ml/min per 1.73 m or less for patients with a baseline eGFR more than 60 ml/min per 1.73 m or a confirmed 25% decline in eGFR for patients with a baseline eGFR of 60 ml/min per 1.73 m or less. Incidence rates of CKD were compared between HCV groups (anti-HCV-negative, anti-HCV-positive with or without viremia) using Poisson regression.

RESULTS

Of 8235 patients with known anti-HCV status, 2052 (24.9%) were anti-HCV-positive of whom 983 (47.9%) were HCV-RNA-positive, 193 (9.4%) HCV-RNA-negative and 876 (42.7%) had unknown HCV-RNA. At baseline, the median eGFR was 97.6 (interquartile range 83.8-113.0) ml/min per 1.73 m. During 36123 person-years of follow-up (PYFU), 495 patients progressed to CKD (6.0%) with an incidence rate of 14.5 per 1000 PYFU (95% confidence interval 12.5-14.9). In a multivariate Poisson model, patients who were anti-HCV-positive with HCV viremia had a higher incidence rate of CKD, whereas patients with cleared HCV infection had a similar incidence rate of CKD compared with anti-HCV-negative patients. There was no association between CKD and HCV genotype.

CONCLUSION

Compared with HIV-monoinfected patients, HIV-positive patients with chronic rather than cleared HCV infection were at increased risk of developing CKD, suggesting a contribution from active HCV infection toward the pathogenesis of CKD.

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.

Comorbid diabetes and the risk of progressive chronic kidney disease in HIV-infected adults: data from the Veterans Aging Cohort Study

INTRODUCTION

Approximately, 15% of HIV-infected individuals have comorbid diabetes. Studies suggest that HIV and diabetes have an additive effect on chronic kidney disease (CKD) progression; however, this observation may be confounded by differences in traditional CKD risk factors.

METHODS

We studied a national cohort of HIV-infected and matched HIV-uninfected individuals who received care through the Veterans Healthcare Administration. Subjects were divided into 4 groups based on baseline HIV and diabetes status, and the rate of progression to an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73m was compared using Cox-proportional hazards modeling to adjust for CKD risk factors.

RESULTS

About 31,072 veterans with baseline eGFR ≥45 mL/min/1.73m (10,626 with HIV only, 5088 with diabetes only, and 1796 with both) were followed for a median of 5 years. Mean baseline eGFR was 94 mL/min/1.73m, and 7% progressed to an eGFR < 45 mL/min/1.73m. Compared with those without HIV or diabetes, the relative rate of progression was increased in individuals with diabetes only [adjusted hazard ratio (HR) 2.48; 95% confidence interval (CI): 2.19 to 2.80], HIV only [HR: 2.80, 95% CI: 2.50 to 3.15], and both HIV and diabetes [HR: 4.47, 95% CI: 3.87 to 5.17].

DISCUSSION

Compared with patients with only HIV or diabetes, patients with both diagnoses are at significantly increased risk of progressive CKD even after adjusting for traditional CKD risk factors. Future studies should evaluate the relative contribution of complex comorbidities and accompanying polypharmacy to the risk of CKD in HIV-infected individuals and prospectively investigate the use of cART, glycemic control, and adjunctive therapy to delay CKD progression.

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.

Episodes of HIV viremia and the risk of non-AIDS diseases in patients on suppressive antiretroviral therapy

BACKGROUND

Several studies reported an association between immunodeficiency and non-AIDS-defining diseases. We investigated whether nonstructured treatment interruptions and episodes of viremia during suppressive combination antiretroviral therapy were independently associated with non-AIDS diseases.

METHODS

Six thousand four hundred forty patients with viral suppression (<50 copies/mL) within 48 weeks of starting combination antiretroviral therapy were selected from the Dutch ATHENA cohort. In proportional hazards models, associations between treatment interruptions, viral suppression, low-level (50-400 copies/mL), and high-level viremia (>400), and serious non-AIDS diseases (cardiovascular disease, chronic renal failure, liver fibrosis/cirrhosis) were investigated by including time-updated cumulative exposure to either viremia and interruptions or HIV RNA >400 copies per milliliter.

RESULTS

During 24,603 person-years, of which 88.5% occurred during viral suppression, 102 patients developed cardiovascular disease, 54 chronic renal failure, and 70 liver fibrosis/cirrhosis. Overall incidence of non-AIDS diseases ranged from 1.41 (95% confidence interval: 0.73 to 2.46) per 100 person-years for CD4 counts <200 to 0.71 (0.49 to 1.00) for CD4 ≥500 cells per cubic millimeter. Compared with viral suppression, high-level viremia was associated only with cardiovascular disease (relative hazard: 1.37, 1.04 to 1.81 per year longer), whereas interruptions and low-level viremia were not associated with non-AIDS diseases. Relative hazards for cumulative exposure to RNA >400 versus ≤400 copies per milliliter were 1.32 (1.01 to 1.73) for cardiovascular disease, 1.13 (0.66 to 1.92) for renal failure, and 0.86 (0.51 to 1.44) for fibrosis/cirrhosis.

CONCLUSIONS

Lower CD4 counts are associated with increased risk of non-AIDS diseases, whereas high-level viremia seems to be independently associated with cardiovascular disease. However, the power to detect associations with viremia or interruptions may have been limited as most events occurred during viral suppression.

Renal toxicity associated with antiretroviral therapy

Renal disease is becoming an increasingly prevalent comorbidity in patients with human immunodeficiency virus (HIV) infection. The increase in life expectancy following the introduction of highly active antiretroviral therapy (HAART) and the long-term development of metabolic complications (such as diabetes and dyslipidaemia), hypertension, and vascular diseases can contribute to the increasing frequency in the recognition of renal impairment in HIV-infected patients. Some antiretroviral agents, and particularly tenofovir, have been associated with nephrotoxic drug effects, including decline in glomerular filtration rate, proximal tubular damage, and acute kidney injury. The occurrence of clinically evident renal toxicity in patients treated with HAART seems to be very low, but glomerular or tubular subclinical dysfunction may occur more frequently. Therefore, careful clinical and laboratory monitoring for the early recognition of renal abnormalities is recommended for all subjects receiving antiretroviral treatment. In this article, the current knowledge about the nephrotoxic effects of antiretroviral agents has been reviewed, and an algorithm for screening and management of HAART-related kidney disease is proposed in the light of the most recent clinical studies and international guidelines.

Macro CK2 accumulation in tenofovir-treated HIV patients is facilitated by CK oligomer stabilization but is not predictive for pathology

BACKGROUND

Ubiquitous mitochondrial creatine kinase (uMtCK) accumulates as macroenzyme creatine kinase type 2 (macro CK2) in the serum of HIV-infected patients under a tenofovir disoproxil fumarate (TDF)-containing antiretroviral regimen. The genesis and clinical significance of this finding is unclear.

METHODS

A prospective observational 5-year follow-up study was performed on those patients in which macro CK2 appearance was initially described ('TDF switch study' cohort). In addition, tenofovir (TFV), its prodrug TDF and its active, intracellular derivative TFV diphosphate (TDP) were tested in vitro for their effects on different key properties of uMtCK to clarify possible interactions of uMtCK with TFV compounds.

RESULTS

In just under 5 years of continuous TDF treatment, only 4/12 (33%) patients remained macro CK2-positive, whereas 8/12 (66%) originally positive patients were macro CK2-negative at the end of follow-up. Prospective clinical follow-up data indicate that macro CK2 appearance under TDF is not associated with significant cell damage or occurrence of malignancies. A trend towards grade 1 hypophosphataemia suggests subclinical proximal tubular dysfunction in macro-CK2-positive patients, although it was not associated with a significant decrease in estimated glomerular filtration rate. In vitro, TFV, TDF and TDP did not interfere with uMtCK enzyme activity as competitive inhibitors or pseudo-substrates, but TFV and TDF stabilized the native uMtCK octameric structure in dilute solutions.

CONCLUSIONS

Appearance of octameric uMtCK as macro CK2 in the serum of TDF-treated patients is suggested to result from a combination of low-level mitochondrial damage caused by subclinical renal tubular dysfunction together with possible compensatory uMtCK overexpression and a putative concomitant stabilization of uMtCK octamers by higher levels of TFV in proximal tubules.

Switching to tenofovir/emtricitabine from abacavir/lamivudine in HIV-infected adults with raised cholesterol: effect on lipid profiles

BACKGROUND

The aim of this study was to investigate the effect on fasting lipid parameters of switching to tenofovir disoproxil fumarate (TDF) plus emtricitabine (FTC) from abacavir (ABC) plus lamivudine (3TC; both fixed-dose combinations), while maintaining ritonavir-boosted lopinavir (LPV/r).

METHODS

This was an open-label randomized two-arm 12-week controlled study in virologically suppressed HIV-infected patients with elevated cholesterol (≥5.2 mmol/l). Patients stable on ABC/3TC plus LPV/r either continued treatment or switched to TDF/FTC plus LPV/r for 12 weeks. Standard efficacy and safety end points (including fasting lipids) were assessed.

RESULTS

In total, 85 subjects were treated (n=42 ABC/FTC and n=43 TDF/3TC). A statistically significant decrease in total cholesterol was observed in the TDF/FTC group: from median (IQR) 6.22 mmol/l (5.91-6.77) at baseline to 5.75 mmol/l (5.04-6.18) at week 12 (median [IQR] change from baseline -0.73 mmol/l [-1.20- -0.18]; P<0.001). No notable change was observed for the ABC/3TC group. The difference between groups at week 12 was -0.82 mmol/l (P<0.001). For TDF/FTC (but not for ABC/3TC), statistically significant reductions (P<0.05) from baseline were observed in total, low-density lipoprotein, high-density lipoprotein (HDL)- and non-HDL cholesterol (at weeks 4 and 12). Statistically significant decreases were observed in median estimated creatinine clearance (Cockcroft-Gault) from baseline to week 12 for patients who switched to TDF/FTC (-5.47 ml/min) versus the ABC/3TC group (-2.15 ml/min; P=0.016 between groups). Virological suppression was maintained in both groups. No new safety issues were identified.

CONCLUSIONS

Switching to TDF/FTC from ABC/3TC was associated with rapid improvements in fasting lipid parameters and continued virological control in patients receiving LPV/r as the third component of antiretroviral therapy. The effect of these changes on clinical end points remains unclear and would need to be evaluated in a longer-term study.

Total protein, albumin and low-molecular-weight protein excretion in HIV-positive patients

BACKGROUND

Chronic kidney disease is common in HIV positive patients and renal tubular dysfunction has been reported in those receiving combination antiretroviral therapy (cART). Tenofovir (TFV) in particular has been linked to severe renal tubular disease as well as proximal tubular dysfunction. Markedly elevated urinary concentrations of retinal-binding protein (RBP) have been reported in patients with severe renal tubular disease, and low-molecular-weight proteins (LMWP) such as RBP may be useful in clinical practice to assess renal tubular function in patients receiving TFV. We analysed 3 LMWP as well as protein and albumin in the urine of a sample of HIV positive patients.

METHODS

In a cross-sectional fashion, total protein, albumin, RBP, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) were quantified in random urine samples of 317 HIV positive outpatients and expressed as the ratio-to-creatinine (RBPCR, CCR and NGALCR). Exposure to cART was categorised as none, cART without TFV, and cART containing TFV and a non-nucleoside reverse-transcriptase-inhibitor (TFV/NNRTI) or TFV and a protease-inhibitor (TFV/PI).

RESULTS

Proteinuria was present in 10.4 % and microalbuminuria in 16.7 % of patients. Albumin accounted for approximately 10 % of total urinary protein. RBPCR was within the reference range in 95 % of patients while NGALCR was elevated in 67 % of patients. No overall differences in urine protein, albumin, and LMWP levels were observed among patients stratified by cART exposure, although a greater proportion of patients exposed to TFV/PI had RBPCR >38.8 μg/mmol (343 μg/g) (p = 0.003). In multivariate analyses, black ethnicity (OR 0.43, 95 % CI 0.24, 0.77) and eGFR <75 mL/min/1.73 m2 (OR 3.54, 95 % CI 1.61, 7.80) were independently associated with upper quartile (UQ) RBPCR. RBPCR correlated well to CCR (r2 = 0.71), but not to NGALCR, PCR or ACR.

CONCLUSIONS

In HIV positive patients, proteinuria was predominantly of tubular origin and microalbuminuria was common. RBPCR in patients without overt renal tubular disease was generally within the reference range, including those receiving TFV. RBP therefore appears a promising biomarker for monitoring renal tubular function in patients receiving TFV and for distinguishing patients with normal tubular function or mild tubular dysfunction from those with severe renal tubular disease or Fanconi syndrome.

Hepatitis B and C co-infection are independent predictors of progressive kidney disease in HIV-positive, antiretroviral-treated adults

Chronic kidney disease (CKD) is an important cause of morbidity and mortality in HIV-positive individuals. Hepatitis C (HCV) co-infection has been associated with increased risk of CKD, but prior studies lack information on potential mechanisms. We evaluated the association between HCV or hepatitis B (HBV) co-infection and progressive CKD among 3,441 antiretroviral-treated clinical trial participants. Progressive CKD was defined as the composite of end-stage renal disease, renal death, or significant glomerular filtration rate (eGFR) decline (25% decline to eGFR <60 mL/min/1.73 m(2) or 25% decline with a baseline <60). Generalized Estimating Equations were used to model the odds of progressive CKD. At baseline, 13.8% and 3.3% of participants were co-infected with HCV and HBV, respectively. Median eGFR was 111, and 3.7% developed progressive CKD. After adjustment, the odds of progressive CKD were increased in participants with HCV (OR 1.72, 95% CI 1.07-2.76) or HBV (OR 2.26, 95% CI 1.15-4.44). Participants with undetectable or low HCV-RNA had similar odds of progressive CKD as HCV seronegative participants, while participants with HCV-RNA >800,000 IU/ml had increased odds (OR 3.07; 95% CI 1.60-5.90). Interleukin-6, hyaluronic acid, and the FIB-4 hepatic fibrosis index were higher among participants who developed progressive CKD, but were no longer associated with progressive CKD after adjustment. Future studies should validate the relationship between HCV viremia and CKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00027352; NCT00004978.

Determinants of incident chronic kidney disease and progression in a cohort of HIV-infected persons with unrestricted access to health care

OBJECTIVES

As socioeconomic factors may impact the risk of chronic kidney disease (CKD), we evaluated the incidence and risk factors of incident CKD among an HIV-infected cohort with universal access to health care and minimal injecting drug use (IDU).

METHODS

Incident CKD was defined as an estimated glomerular filteration rate (eGFR) <60 ml/min/1.73 m(2) for ≥ 90 days. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Rates were calculated per 1000 person-years (PY). Associations with outcomes were assessed using two separate Cox proportional hazard models, adjusting for baseline and time-updated covariates.

RESULTS

Among 3360 participants [median age 29 years; 92% male; 44% African American (AA)] contributing 23,091 PY of follow-up, 116 developed incident CKD [5.0/1000 PY; 95% confidence interval (CI) 4.2-6.0/1000 PY]. The median first eGFR value was 97.0 mL/min/1.73 m(2) [interquartile range (IQR) 85.3-110.1 mL/min/1.73 m(2)]. Baseline factors associated with CKD included older age, lower CD4 count at HIV diagnosis [compared with CD4 count ≥ 500 cells/μL, hazard ratio (HR) 2.1 (95% CI 1.2-3.8) for CD4 count 350-499 cells/μL; HR 3.6 (95% CI 2.0-6.3) for CD4 count 201-349 cells/μL; HR 4.3 (95% CI 2.0-9.4) for CD4 count ≤ 200 cells/μL], and HIV diagnosis in the pre-highly active antiretroviral therapy (HAART) era. In the time-updated model, low nadir CD4 counts, diabetes, hepatitis B, hypertension and less HAART use were also associated with CKD. AA ethnicity was not associated with incident CKD in either model.

CONCLUSIONS

The low incidence of CKD and the lack of association with ethnicity observed in this study may in part be attributable to unique features of our cohort such as younger age, early HIV diagnosis, minimal IDU, and unrestricted access to care. Lower baseline CD4 counts were significantly associated with incident CKD, suggesting early HIV diagnosis and timely introduction of HAART may reduce the burden of CKD.

High incidence of renal stones among HIV-infected patients on ritonavir-boosted atazanavir than in those receiving other protease inhibitor-containing antiretroviral therapy

BACKGROUND

Little information is available on the incidence of renal stones with ritonavir-boosted atazanavir (ATV/r) use.

METHODS

In a single-center study, the incidence of renal stones was compared between human immunodeficiency virus (HIV)-infected patients who commenced ritonavir-boosted atazanavir (ATV/r)-containing antiretroviral (ARV) therapy (the ATV/r group) and those who were receiving other protease inhibitors (the other PIs group). The effects of ATV/r were estimated by univariate and multivariate Cox proportional hazards regression models. Other possible risk factors were evaluated by univariate analysis, and those found to be significant were entered into multivariate analysis.

RESULTS

Renal stones were diagnosed in 31 patients (23.7 cases per 1000 person-years) in the ATV/r group (n = 465) and 4 in patients (2.2 cases per 1000 person-years) in the other PIs group (n = 775). ATV/r use was significantly associated with renal stones, by univariate and multivariate analyses (adjusted hazard ratio, 10.44; 95% confidence interval [CI], 3.685-29.59; P < .001). ATV/r remained a significant risk factor for renal stones in all subgroups stratified by the median values of baseline variables. In the 31 patients receiving ATV/r who developed renal stones, the median time from commencement of ATV/r to diagnosis was 24.5 months (interquartile range, 14.7-34.6 months). Of the 18 patients who continued ATV/r despite the diagnosis of renal stones, 6 (33.3%) experienced recurrence. No patient who discontinued ATV/r experienced recurrence during the observation period (250.6 person-months).

CONCLUSIONS

The incidence of renal stones was substantially higher among patients in the ATV/r group, compared with patients in the other PIs group. Continuation of ATV/r after diagnosis of renal stones was associated with a high rate of recurrence. Switching ATV/r to other ARVs is warranted in patients who develop renal stones.

Renal function and incidence of chronic kidney disease in HIV patients: a Danish cohort study

BACKGROUND

Impaired renal function is of major concern in human immunodeficiency virus (HIV)-infected patients.

METHODS

We used a mixed effects linear regression model to determine estimated glomerular filtration rates (eGFRs) in a population-based cohort of incident Danish HIV patients and stratified on baseline eGFR (eGFR(B)) < 90 and ≥ 90 ml/min per 1.73 m(2). Incidence rate ratios (IRRs) for chronic kidney disease (CKD) - 2 consecutive eGFR values < 60 ml/min per 1.73 m(2) measured > 3 months apart - were estimated (time-updated Cox-regression model).

RESULTS

The effect of time with HIV on eGFR was small in both strata (- 0.09 (95% confidence interval (CI) - 0.27, 0.09) and - 0.46 (95% CI - 0.64, - 0.27) ml/min per 1.73 m(2) per y). Treatment with tenofovir and indinavir was associated with lower eGFR in both strata: tenofovir - 2.00 (95% CI - 3.45, - 0.56) and - 1.94 (95% CI - 3.43, - 0.44) ml/min per 1.73 m(2) and indinavir - 2.14 (95% CI - 3.63, - 0.64) and - 3.29 (95% CI - 5.25, - 1.32) ml/min per 1.73 m(2). Nevirapine, atazanavir, and the combination of tenofovir and atazanavir were associated with lower eGFR in patients with eGFR(B) < 90 ml/min per 1.73 m(2). Highly active antiretroviral therapy (HAART) and exposure to tenofovir and atazanavir in combination were associated with CKD in patients with eGFR(B) < 90 ml/min per 1.73 m(2) (adjusted IRRs 6.08 (95% CI 2.76-13.41) and 26.75 (95% CI 9.54-75.05)).

CONCLUSION

Tenofovir and indinavir reduce eGFR, while time with HIV only has a modest effect on this parameter. Low eGFR(B) is associated with an increased risk of CKD, especially when receiving HAART regimens containing the combination tenofovir/atazanavir.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

Trends in reasons for hospitalization in a multisite United States cohort of persons living with HIV, 2001-2008

INTRODUCTION

Hospitalization rates for comorbid conditions among persons living with HIV in the current highly active antiretroviral therapy era are unknown.

METHODS

Hospitalization data from 2001 to 2008 were obtained on 11,645 adults receiving longitudinal HIV care at 4 geographically diverse US HIV clinics within the HIV Research Network. Modified clinical classification software from the Agency for Healthcare Research and Quality assigned primary ICD-9 codes into diagnostic categories. Analysis was performed with repeated measures negative binomial regression.

RESULTS

During 2001 to 2008, the rate of AIDS-defining illness (ADI) hospitalizations declined from 6.7 to 2.7 per 100 person-years, incidence rate ratio per year, 0.89 (0.87, 0.91). Among the other diagnostic categories with average rates >2 per 100 person-years, cardiovascular hospitalizations increased over time [1.07 (1.03, 1.11)], whereas non-AIDS-defining infection [0.98 (0.96, 1.00)], psychiatric [0.96 (0.93, 1.00)], and gastrointestinal/liver [0.96 (0.92, 1.00)] were slightly decreasing or stable. Although less frequent overall, renal and pulmonary admissions also increased over time in univariate and multivariate analyses. Of all diagnostic categories, ADI admissions had the longest mean length of stay, 10.5 days.

DISCUSSION

ADI hospitalizations have continued to decline in recent years but are still relatively frequent and potentially costly given long lengths of stay. Increases or stability in the rates of chronic end-organ disease admissions imply a need for broader medical knowledge among individual clinicians and/or teams who care for persons living with HIV and a need for long-term access to medications for these conditions.

Antihypertensive Drugs in Patients Treated with Antiretroviral

Objective:

To review the literature for information regarding pharmacokinetic interactions between antiretrovirals and antihypertensive agents, evaluate the clinical significance of these interactions, and analyze the effect of antihypertensive drugs on the metabolic complications frequently observed in HIV-infected patients to emphasize the advantages and inconveniences of every class of antihypertensive drugs in association with antiretrovirals.

Data Sources:

A literature search was conducted via PubMed and MEDLINE (1950-November 2011) using the search terms drug interactions, cytochrome P450, names of antiretrovirals, names of commonly prescribed antihypertensive drugs, pharmacokinetics, and metabolic complications. Reference citations from relevant publications, manufacturers’ product information, and www.HIV-druginteracttons.org were also reviewed.

Study Selection And Data Extractions:

All articles with an English abstract identified through the data search were examined. Of these, pharmacologic reviews, studies, and case reports were evaluated.

Data Synthesis:

Antihypertensive drugs interact with several antiretroviral drugs, non nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (Pls) in particular. Pharmacokinetic interactions are less expected with diuretics, jî-blockers excreted by the kidney, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin II receptor blockers (ARBs) other than losartan and irbesartan. Calcium channel blockers (CCBs) are metabolized by CYP3A4, with the potential for interaction with NNRTIs and Pls. Because CCBs do not adversely affect glucose or lipid metabolism or renal function, they may be preferred in patients with such complications. ACE inhibitors and ARBs may exert favorable effects on glucose homeostasis. In addition, they may significantly reduce protein excretion and further slow the progression of renal disease.

Conclusions:

The choice of antihypertensive drugs in HIV-infected patients is complex and must take into account the metabolic pathways of antiretroviral drugs and antihypertensive drugs with the potential of pharmacokinetic interactions, as well as the effect of antihypertensive drugs on some biological parameters.

Association of tenofovir exposure with kidney disease risk in HIV infection

OBJECTIVE

Despite widespread HAART use, HIV disease remains associated with increased risk of kidney disease. Whether tenofovir use is associated with higher risk of kidney disease is controversial.

DESIGN

We evaluated the association of cumulative and ever exposure to tenofovir on kidney outcomes in 10,841 HIV-infected patients from the Veterans Health Administration who initiated antiretroviral therapy from 1997 to 2007.

METHODS

Cox proportional hazards and marginal structural models evaluated associations between tenofovir and time to first occurrence of proteinuria (two consecutive urine dipstick measurements ≥30 mg/dl), rapid decline in kidney function (≥3 ml/min per 1.73 m annual decline), and chronic kidney disease (CKD; estimated glomerular filtration rate <60 ml/min per 1.73 m).

RESULTS

Median follow-up ranged from 3.9 years (proteinuria) to 5.5 years (CKD), during which 3400 proteinuria, 3078 rapid decline, and 533 CKD events occurred. After multivariable adjustment, each year of exposure to tenofovir was associated with 34% increased risk of proteinuria [95% confidence interval (CI) 25-45, P < 0.0001], 11% increased risk of rapid decline (3-18, P = 0.0033), and 33% increased risk of CKD (18-51, P < 0.0001). Preexisting renal risk factors did not appear to worsen the effects of tenofovir. Other antiretroviral drugs showed weaker or inconsistent associations with kidney disease events. Among those who discontinued tenofovir use, risk of kidney disease events did not appear to decrease during follow-up.

CONCLUSION

Tenofovir exposure was independently associated with increased risk for three types of kidney disease events, and did not appear to be reversible. Because subtle kidney function decline affects long-term morbidity and mortality, the balance between efficacy and probable adverse effects requires further study.

Glomerular dysfunction and associated risk factors over 4-5 years following antiretroviral therapy initiation in Africa

BACKGROUND

The aim of this study was to investigate long-term renal function in HIV-infected adults initiating antiretroviral therapy (ART) with a CD4(+) T-cell count < 200 cells/mm³ in Africa.

METHODS

This was an observational analysis within the DART trial randomizing 3,316 adults to routine laboratory and clinical monitoring (LCM) or clinically driven monitoring (CDM). Serum creatinine was measured pre-ART (all ≤ 360 μmol/l), at weeks 4 and 12, then every 12 weeks for 4-5 years; estimated glomerular filtration rate (eGFR) was determined using the Cockcroft-Gault formula. We analysed eGFR changes, and cumulative incidences of eGFR< 30 ml/min/1.73 m² and chronic kidney disease (CKD; <60 ml/min/1.73 m² or 25% decrease if <60 ml/min/1.73 m² pre-ART; confirmed >3 months).

RESULTS

At ART initiation, median CD4(+) T-cell count was 86 cells/mm³; 1,492 (45%) participants had mild (60-< 90 ml/min/1.73 m²), 237 (7%) moderate (30-<60 ml/min/1.73 m² and 7 (0.2%) severe (15-<30 ml/min/1.73 m²) decreases in eGFR. First-line ART was zidovudine/lamivudine plus tenofovir (74%), abacavir (9%) or nevirapine (17%). By 4 years, cumulative incidence of eGFR<30 ml/min/1.73 m² was 2.8% (n=90) and CKD was 5.0% (n=162). Adjusted eGFR increases to 4 years were 1, 9 and 6 ml/min/1.73 m² with tenofovir, abacavir and nevirapine, respectively (P<0.001), and 4 and 2 ml/min/1.73 m² for LCM and CDM, respectively (P=0.005; 2 and 3 ml/min/1.73 m² to 5 years; P=0.81).

CONCLUSIONS

On all regimens and monitoring strategies, severe eGFR impairment was infrequent; differences in eGFR changes were small, suggesting that first-line ART, including tenofovir, can be given safely without routine renal function monitoring.

Relative risk of renal disease among people living with HIV: a systematic review and meta-analysis

Background

Antiretroviral therapy (ART) has substantially decreased mortality and HIV-related morbidity. However, other morbidities appear to be more common among PLHIV than in the general population. This study aimed to estimate the relative risk of renal disease among people living with HIV (PLHIV) compared to the HIV-uninfected population.

Methods

We conducted a systematic review and meta-analysis of relative risks of renal disease among populations of PLHIV reported in studies from the peer-reviewed literature. We searched Medline for relevant journal articles published before September 2010, yielding papers published during or after 2002. We also searched conference proceedings of the International AIDS Society (IAS) and Conference on Retroviruses and Opportunistic Infections (CROI) prior to and including 2010. Eligible studies were observational studies reporting renal disease defined as acute or chronic reduced renal function with glomerular filtration rate less than or equal to 60 ml/min/1.73 m² among HIV-positive adults. Pooled relative risks were calculated for various groupings, including class of ART drugs administered.

Results

The overall relative risk of renal disease was 3.87 (95% CI: 2.85-6.85) among HIV-infected people compared to HIV-uninfected people. The relative risk of renal disease among people with late-stage HIV infection (AIDS) was 3.32 (1.86-5.93) compared to other PLHIV. The relative risk of renal disease among PLHIV who were receiving antiretroviral therapy (ART) was 0.54 (0.29-0.99) compared to treatment-naïve PLHIV; the relative risk of renal disease among PLHIV who were treated with tenofovir was 1.56 (0.83-2.93) compared to PLHIV who were treated with non-tenofovir therapy. The risk of renal disease was also found to significantly increase with age.

Conclusion

PLHIV are at increased risk of renal disease, with greater risk at later stages of infection and at older ages. ART prolongs survival and decreases the risk of renal disease. However, less reduction in renal disease risk occurs for Tenofovir-containing ART than for other regimens.

Simultaneous measurement of urinary albumin and total protein may facilitate decision-making in HIV-infected patients with proteinuria

OBJECTIVE

We recently showed that a urine albumin/total protein ratio (uAPR) <0.4 identifies tubular pathology in proteinuric patients. In tubular disorders, proteinuria is usually of low molecular weight and contains relatively little albumin. We tested the hypothesis that uAPR is useful in identifying tubular pathology related to antiretroviral use in HIV-infected patients.

METHODS

We retrospectively identified urine protein/creatinine ratios (uPCRs) in HIV-infected patients. A subset of samples had uPCR and urine albumin/creatinie ratio (uACR) measured simultaneously. We classified proteinuric patients (uPCR >30 mg/mmol) into two groups: those with predominantly 'tubular' proteinuria (TP) (uAPR <0.4) and those with predominantly 'glomerular' proteinuria (GP) (uAPR ≥ 0.4).

RESULTS

A total of 618 of 5244 samples from 1378 patients had uPCR ≥ 30 mg/mmol. uAPRs were available in 144 patients: 46 patients (32%) had TP and 21 (15%) GP; the remainder had uPCR <30 mg/mmol. The TP group had a higher fractional excretion of phosphate compared with the GP group (mean 27% vs. 16%, respectively; P<0.01). Patients with TP were more likely to be on tenofovir and/or a boosted protease inhibitor compared with those with GP. In 18 patients with heavy proteinuria (uPCR >100 mg/mmol), a renal assessment was made; eight had a kidney biopsy. In all cases, the uAPR results correlated with the nephrological diagnosis.

CONCLUSIONS

In HIV-infected patients, measuring uAPR may help to identify patients in whom a renal biopsy is indicated, and those in whom tubular dysfunction might be an important cause of proteinuria and which may be related to antiretroviral toxicity. We suggest that this would be useful as a routine screening procedure in patients with proteinuria.

Renal function in patients with HIV starting therapy with tenofovir and either efavirenz, lopinavir or atazanavir

BACKGROUND

Tenofovir is associated with reduced renal function, but it is not clear whether there is a greater decline in renal function when tenofovir is co-administered with a boosted protease inhibitor rather than with a nonnucleoside reverse transcriptase inhibitor (NNRTI).

METHODS

We calculated the estimated glomerular filtration rate (eGFR) for patients in the Swiss HIV Cohort Study. We estimated the difference in eGFR over time between first therapies containing tenofovir and either the NNRTI efavirenz or the protease inhibitors lopinavir (LPV/r) or atazanavir (ATV/r), both boosted with ritonavir.

RESULTS

Patients on a first therapy of tenofovir co-administered with efavirenz (n  = 484), LPV/r (n = 269) and ATV/r (n =  187) were followed for a median of 1.7, 1.2 and 1.3 years, respectively. Relative to tenofovir and efavirenz, the estimated difference in eGFR for tenofovir and LPV/r was -2.6 ml/min per 1.73 m [95% confidence interval (CI) -7.3 to 2.2) during the first 6 months of therapy, then followed by a difference of 0.0 ml/min per 1.73 m (95% CI -1.1 to 1.1) for each additional 6 months of therapy. Relative to tenofovir and efavirenz, the estimated difference in eGFR for tenofovir and ATV/r was -7.6 ml/min per 1.73 m (95% CI -11.8 to -3.4) during the first 6 months of therapy, then followed by a difference of -0.5 ml/min per 1.73 m (95% CI -1.6 to 0.7) for each additional 6 months of therapy.

CONCLUSION

Tenofovir with either boosted protease inhibitor leads to a greater initial decline in eGFR than tenofovir with efavirenz; this decline may be worse with ATV/r than with LPV/r.

HIV-associated kidney disease in the context of an aging population

Acute renal failure and chronic kidney disease are more common in HIV-infected patients compared with the general population. Several studies have shown age to be a risk factor for HIV-associated kidney disease. The improved life expectancy of HIV-infected patients as a result of widespread use of antiretroviral therapy has resulted in progressive aging of HIV cohorts in the developed world, and an increased burden of cardiovascular and kidney disease. Consequently, HIV care increasingly needs to incorporate strategies to detect and manage these non-infectious co-morbidities.

Long-term exposure to combination antiretroviral therapy and risk of death from specific causes: no evidence for any previously unidentified increased risk due to antiretroviral therapy

BACKGROUND

Despite the known substantial benefits of combination antiretroviral therapy (cART), cumulative adverse effects could still limit the overall long-term treatment benefit. Therefore we investigated changes in the rate of death with increasing exposure to cART.

METHODS

A total of 12 069 patients were followed from baseline, which was defined as the time of starting cART or enrolment into EuroSIDA whichever occurred later, until death or 6 months after last follow-up visit. Incidence rates of death were calculated per 1000 person-years of follow-up (PYFU) and stratified by time of exposure to cART (≥3 antiretrovirals): less than 2, 2-3.99, 4-5.99, 6-7.99 and more than 8 years. Duration of cART exposure was the cumulative time actually receiving cART. Poisson regression models were fitted for each cause of death separately.

RESULTS

A total of 1297 patients died during 70,613 PYFU [incidence rate 18.3 per 1000 PYFU, 95% confidence interval (CI) 17.4-19.4], 413 due to AIDS (5.85, 95% CI 5.28-6.41) and 884 due to non-AIDS-related cause (12.5, 95% CI 11.7-13.3). After adjustment for confounding variables, including baseline CD4 cell count and HIV RNA, there was a significant decrease in the rate of all-cause and AIDS-related death between 2 and 3.99 years and longer exposure time. In the first 2 years on cART the risk of non-AIDS death was significantly lower, but no significant difference in the rate of non-AIDS-related deaths between 2 and 3.99 years and longer exposure to cART was observed.

CONCLUSION

In conclusion, we found no evidence of an increased risk of both all-cause and non-AIDS-related deaths with long-term cumulative cART exposure.

The New Epidemiology of HIV-Related Kidney Disease

HIV-related kidney disease has been associated with significant morbidity and mortality in the HIV population. It is clear that the epidemiology of HIV-related kidney disease has changed dramatically since the first case reports in 1984. During these early years, the predominant etiology of kidney disease in HIV was recognized as HIV-associated nephropathy (HIVAN), an aggressive form of kidney disease with a high rate of progression to end-stage renal disease (ESRD). Subsequently, with the widespread use of combination antiretroviral therapy (cART), there was a dramatic decrease in the incidence of ESRD attributed to HIV/AIDS. Although the incidence of HIV-related ESRD has plateaued in the last 15 years, the prevalence has continued to increase because of improved survival. Available prevalence estimates do not include HIV-infected individuals with comorbid ESRD, although there is growing evidence that the epidemiology of kidney disease in the HIV-infected population has changed. This article reviews the impact of risk factors such as race, diabetes mellitus, hypertension, hepatitis C virus coinfection, and the chronic use of cART on the changing epidemiology of HIV-related kidney disease. Additionally in this review, we propose potential areas of translational research that will help to further characterize HIV-related kidney disease in the 21^st century.