Kidney function and the risk of cardiovascular events in HIV-1-infected patients

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.

Prevalence of low estimated glomerular filtration rate, proteinuria, and associated risk factors among HIV-infected black patients using Cockroft-Gault and modification of diet in renal disease study equations

OBJECTIVE

To evaluate the prevalence of low estimated glomerular filtration rate (eGFR), proteinuria, and associated risk factors among HIV-infected black patients at primary health care.

METHODS

A cross-sectional screening involving consecutive HIV-infected patients 18 years and older was done. Eighty-eight percent of patients were receiving highly active antiretroviral therapy (94% on first-line regimen: zidovudine + lamivudine + nevirapine). Simplified Modification of Diet in Renal Disease Study and Cockroft-Gault (CG) equations were used to estimate glomerular filtration rate and creatinine clearance, respectively. Determinants of dipstick proteinuria and low kidney function (<60 mL·min(-1)·1.73 m(-2)) were assessed using multivariate logistic regression analysis.

RESULTS

Three hundred HIV-infected (231 females) patients were screened. Their mean age, duration of HIV, and CD4(+) count were 43 ± 9 years, 33 ± 27 months, and 397 ± 224 cells per cubic millimeter, respectively. The prevalence of low eGFR according to Modification of Diet in Renal Disease Study and CG equations was 3% and 10%, respectively. Proteinuria was observed in 20.5% of patients. Only CD4(+) cell count ≤200 cells per cubic millimeter emerged as a strong determinant of low CG creatinine clearance [adjusted odds ratio (OR) 3.03; 95% confidence interval (CI): 1.099 to 8.352], whereas age ≥45 years (adjusted OR 3.69; 95% CI: 1.756 to 7.787), familial history of diabetes mellitus (adjusted OR 2.20; 95% CI: 1.067 to 4.543), and hypertension (adjusted OR 3.07; 95% CI: 1.278 to 7.787) were significantly associated with proteinuria.

CONCLUSIONS

Low eGFR and proteinuria are prevalent among these HIV-infected persons. Immunodeficiency emerged as one of the strongest determinants of renal impairment. This finding emphasizes the importance of highly active antiretroviral therapy in tackling the burden of chronic kidney disease in African HIV population.

Vitamin D deficiency and persistent proteinuria among HIV-infected and uninfected injection drug users

OBJECTIVE

Proteinuria occurs commonly among HIV-infected and uninfected injection drug users (IDUs) and is associated with increased mortality risk. Vitamin D deficiency, highly prevalent among IDUs and potentially modifiable, may contribute to proteinuria. To determine whether vitamin D is associated with proteinuria in this population, we conducted a cross-sectional study in the AIDS Linked to the IntraVenous Experience (ALIVE) Study.

METHODS

25(OH)-vitamin D levels were measured in 268 HIV-infected and 614 HIV-uninfected participants. The association between vitamin D deficiency (<10  ng/ml) and urinary protein excretion was evaluated by linear regression. The odds of persistent proteinuria (urine protein-to-creatinine ratio >200  mg/g on two occasions) associated with vitamin D deficiency was examined using logistic regression.

RESULTS

One-third of participants were vitamin D-deficient. Vitamin D deficiency was independently associated with higher urinary protein excretion (P < 0.05) among HIV-infected and diabetic IDUs (P-interaction < 0.05 for all). Persistent proteinuria occurred in 18% of participants. Vitamin D deficiency was associated with greater than six-fold odds of persistent proteinuria among diabetic IDUs [odds ratio (OR) 6.29, 95% confidence interval (CI) 1.54, 25.69] independent of sociodemographic characteristics, comorbid conditions, body mass index, and impaired kidney function [estimated glomerular filtration rate (eGFR) <60  ml/min per 1.73  m(2)]; no association, however, was observed among nondiabetic IDUs (OR 1.06, 95% CI 0.64, 1.76) (P-interaction <0.05).

CONCLUSIONS

Vitamin D deficiency was associated with higher urinary protein excretion among those with HIV infection and diabetes. Vitamin D deficiency was independently associated with persistent proteinuria among diabetic IDUs, although not in nondiabetic persons. Whether vitamin D repletion ameliorates proteinuria in these patients requires further study.

HIV-associated kidney glomerular diseases: changes with time and HAART

BACKGROUND

Treatment and co-morbidities of human immunodeficiency virus (HIV)-infected individuals have changed dramatically in the last 20 years with a potential impact on renal complications. Our objective was to assess the change in distribution of the glomerular diseases in HIV patients.

METHODS

We retrospectively analysed demographic, clinical, laboratory and renal histopathological data of 88 HIV-infected patients presenting with a biopsy-proven glomerular disease between 1995 and 2007.

RESULTS

In our study including 66% Black patients, HIV-associated nephropathy (HIVAN) was observed in 26 cases, classic focal segmental glomerulosclerosis (FSGS) in 23 cases, immune complex glomerulonephritis in 20 cases and other glomerulopathies in 19 patients. HIVAN decreased over time, while FSGS emerged as the most common cause of glomerular diseases (46.9%) in HIV-infected individuals undergoing kidney biopsy in the last 2004-07 period. Patients with HIVAN were usually Black (97%), with CD4 <200/mL (P = 0.01) and glomerular filtration rate <30 mL/min/1.73 m(2) (P < 0.01). Compared to HIVAN, patients with classic FSGS were less often Black (P < 0.01), have been infected for longer (P = 0.03), were more often co-infected with hepatitis C virus (P = 0.05), showed more often cardiovascular (CV) risk factors (P < 0.01), had less often CD4 <200/mL (P = 0.01), lower HIV viral load (P = 0.01) and tended to be older (P = 0.06).

CONCLUSIONS

Classic FSGS associated with metabolic and CV risk factors has overcome HIVAN in HIV-infected patients. Compared with other glomerulopathies, HIVAN remains strongly associated with severe renal failure, Black origin and CD4 lower than 200/mL at presentation.

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.

Renal issues in HIV infection

Kidney disease remains a prominent complication of HIV disease, despite beneficial effects of antiretroviral therapy on the natural history of HIV-associated nephropathy, and on kidney function in general populations of HIV infected patients. Persons of African descent continue to bear a disproportionate burden of severe kidney disease, as is true for the general population. Recently identified genetic variants in the apolipoprotein L1 gene may contribute to this burden. As is also true for the general population, markers of kidney disease, including microalbuminuria, are sensitive predictors of cardiovascular disease and mortality among persons living with HIV. The emerging experience with kidney transplantation also suggests this to be a viable option in selected patients.

APOL1 risk variants predict histopathology and progression to ESRD in HIV-related kidney disease

With earlier institution of antiretroviral therapy, kidney diseases other than HIV-associated nephropathy (HIVAN) predominate in HIV-infected persons. Outcomes for these diseases are typically worse among those infected with HIV, but the reasons for this are not clear. Here, we examined the role of APOL1 risk variants in predicting renal histopathology and progression to ESRD in 98 HIV-infected African Americans with non-HIVAN kidney disease on biopsy. We used survival analysis to determine time to ESRD associated with APOL1 genotype. Among the 29 patients with two APOL1 risk alleles, the majority (76%) had FSGS and 10% had hypertensive nephrosclerosis. In contrast, among the 54 patients with one APOL1 risk allele, 47% had immune-complex GN as the predominant lesion and only 23% had FSGS. Among the 25 patients with no APOL1 risk allele, 40% had immune-complex GN and 12% had FSGS. In 310 person-years of observation, 29 patients progressed to ESRD. In adjusted analyses, individuals with two APOL1 risk alleles had a nearly three-fold higher risk for ESRD compared with those with one or zero risk alleles (P=0.03). In summary, these data demonstrate an association between APOL1 variants and renal outcomes in non-HIVAN kidney disease, suggesting a possible use for APOL1 genotyping to help guide the care of HIV-infected patients.

Association of immunologic and virologic factors with myocardial infarction rates in a US healthcare system

BACKGROUND

The effects of immunologic and virologic factors on acute myocardial infarction (AMI) rates in patients with HIV are unclear.

METHODS

HIV-infected patients in a US healthcare system were assessed for AMI.

RESULTS

Of 6517 patients with HIV, 273 (4.2%) had an AMI. In a model adjusting for cardiovascular risk factors, antiretroviral medications, and HIV parameters, CD4 count less than 200/mm (odds ratio, 1.74; 95% confidence interval, 1.07 to 2.81; P = 0.02) predicted AMI. Increased HIV viral load was associated with AMI accounting for cardiovascular disease risk factors and antiretroviral medications but was not significant when CD4 count was considered.

CONCLUSIONS

Immunologic control appears to be the most important HIV-related factor associated with AMI.

Pre-existing albuminuria predicts AIDS and non-AIDS mortality in women initiating antiretroviral therapy

BACKGROUND

We previously reported an increased risk of all-cause and AIDS mortality among HIV-infected women with albuminuria (proteinuria or microalbuminuria) enrolled in the Women's Interagency HIV Study (WIHS) prior to the introduction of HAART.

METHODS

The current analysis includes 1,073 WIHS participants who subsequently initiated HAART. Urinalysis for proteinuria and semi-quantitative testing for microalbuminuria from two consecutive study visits prior to HAART initiation were categorized as follows: confirmed proteinuria (both specimens positive for protein), confirmed microalbuminuria (both specimens positive with at least one microalbuminuria), unconfirmed albuminuria (one specimen positive for proteinuria or microalbuminuria), or negative (both specimens negative). Time from HAART initiation to death was modelled using proportional hazards analysis.

RESULTS

Compared with the reference group of women with two negative specimens, the hazard ratio (HR) for all-cause mortality was significantly increased for women with confirmed microalbuminuria (HR 1.9, 95% CI 1.2-2.9). Confirmed microalbuminuria was also independently associated with AIDS death (HR 2.3, 95% CI 1.3-4.3), whereas women with confirmed proteinuria were at increased risk for non-AIDS death (HR 2.4, 95% CI 1.2-4.6).

CONCLUSIONS

In women initiating HAART, pre-existing microalbuminuria independently predicted increased AIDS mortality, whereas pre-existing proteinuria predicted increased risk of non-AIDS death. Urine testing may identify HIV-infected individuals at increased risk for mortality even after the initiation of HAART. Future studies should consider whether these widely available tests can identify individuals who would benefit from more aggressive management of HIV infection and comorbid conditions associated with mortality in this population.

Abacavir use and cardiovascular disease events: a meta-analysis of published and unpublished data

BACKGROUND

The use of abacavir (ABC) has been associated with an increased risk of cardiovascular disease in some cohort studies. However, no excess risk of myocardial infarction (MI) with ABC therapy has been observed in individual randomized clinical trials (RCTs) and in the aggregated clinical trials database maintained by the manufacturer of ABC.

OBJECTIVE

To combine all the evidence from RCTs by means of meta-analysis to estimate the effect of combined antiretroviral therapy (cART) containing ABC on MI and overall major cardiovascular events (CVEs).

METHODS

Primary outcomes included MI, CVE, adverse events requiring discontinuation of treatment, and overall mortality. We used a conventional Mantel-Haenszel method, with risk ratio and 95% confidence intervals (CIs) or, in the presence of heterogeneity, a random-effect model.

RESULTS

Data were from 28 primary RCTs (9233 participants) comparing ABC-containing cART (4376 participants) to other regimens not containing ABC (4857 controls). MI data were available from 18 trials (31 episodes in 7054 patients) and CVE data from 20 trials (79 episodes in 7899 patients). Compared to the controls, ABC use did not increase significantly the occurrence of MI (risk ratio 0.73, 95% CI 0.39-1.35; P = 0.31), CVE (risk ratio 0.95, 95% CI 0.62-1.44; P = 0.80), overall mortality (risk ratio 1.20, 95% CI 0.63-2.27; P = 0.58), and adverse events requiring discontinuation of treatment (risk ratio 0.82, 95% CI 0.67-1.00; P = 0.05).

CONCLUSION

This meta-analysis of RCTs does not support the hypothesis that ABC-containing cART regimens carry a greater risk of MI or major cardiovascular events relative to comparator cART.

Abacavir use and risk of acute myocardial infarction and cerebrovascular events in the highly active antiretroviral therapy era

BACKGROUND

Some studies have suggested that exposure to antiretroviral therapy (ART) with abacavir is associated with an increased risk of acute myocardial infarction (AMI).

METHODS

Using the Veterans Health Administration's Clinical Case Registry we calculated the risk of AMI and cerebrovascular events (CVA) associated with the cumulative use of abacavir and other nucleoside combinations. We also evaluated the impact of pre-existing chronic kidney disease on the selection of abacavir versus tenofovir in the last recorded ART regimen, and on highly active antiretroviral therapy-associated AMI and CVA risks.

RESULTS

A total of 19,424 human immunodeficiency virus-infected patients contributed 76,376 patient-years of follow. After adjusting for age, hypercholesterolemia, hypertension, type 2 diabetes, and smoking, the hazard ratio (HR) for each year of abacavir use was 1.18 (95% confidence interval [CI], .92-1.50; P=.191) for AMI and 1.16 (95% CI, .98-1.37; P=.096) for CVA. Abacavir use was more common among patients with prior chronic kidney disease than was tenofovir use (12.46% versus 7.15%; P=.0001), and chronic kidney disease was associated with a significantly higher risk of AMI (HR, 2.41; 95% CI, 1.73-3.36), and CVA (HR, 1.80; 95% CI, 1.44-2.24). Compared with patients who received neither tenofovir nor abacavir, patients who received tenofovir had lower risk of AMI (HR, 0.16; 95% CI, .08-.33; P=.0001) and CVA (HR, 0.22; 95% CI, .15-.32; P=.001). Use of abacavir was associated with lower risk of CVA (HR, 0.60; 95% CI, .45-.79).

CONCLUSIONS

We observed no association between cumulative or current abacavir use and AMI or CVA. Abacavir use was more common than was tenofovir use among patients with prior chronic kidney disease, and chronic kidney disease independently predicted higher rates of AMI and CVA.

Renal disease in HIV-infected individuals

PURPOSE OF REVIEW

Highly active antiretroviral therapy (HAART) has resulted in a marked decrease in AIDS-related conditions and death. With improved survival, cardiovascular disease, hepatic, renal disease, and non-AIDS-related cancers represent an increasing burden for HIV-infected individuals.

RECENT FINDINGS

HIV-associated nephropathy (HIVAN), acute renal injury, HAART, and comorbid conditions such as hepatitis C, hypertension, and diabetes are among the multiple causes of renal disease. In HIVAN there is incomplete understanding of the interaction of the virus with renal cells and the host genetics leading to susceptibility to this form of renal dysfunction. There is agreement that a baseline estimated glomerular filtration should be obtained and that renal function should be monitored during antiretroviral therapy. There is, however, no agreement as to the most accurate method of estimating GFR. Renal transplantation has emerged as a feasible and successful modality of management of end-stage renal disease (ESRD) in HIV-infected individuals.

SUMMARY

Kidney disease represents an increasing concern in the care of HIV-infected persons, although there are questions remaining regarding the pathophysiology of HIVAN. Transplantation, however, can be carried out safely in infected persons with ESRD.

Comparative analysis of the new chronic kidney disease epidemiology collaboration and the modification of diet in renal disease equations for estimation of glomerular filtration rate in HIV type 1-infected subjects

Recently, a new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula was presented as a better alternative to the modification of diet in renal disease (MDRD) formula for GFR estimation (eGFR) in patients with relatively well-preserved kidney function. The main objective of our study was to compare the eGFR results arrived by the new CKD-EPI to the older MDRD equation in antiretroviral (ARV)-naive and ARV-treated HIV-1-infected patients. The study was performed in 287 adult HIV-1-infected patients and was an evaluation comparing eGFR results based on age, gender, race, and serum creatinine. The biggest difference in estimated glomerular filtration rate (eGFR) measured by the two formulas was seen in ARV-naive men with well-preserved kidney function (p = 0.001). Moreover, we found a significant negative correlation between mean difference in eGFR measured by the two equations and the age of the studied subjects (r = -0.37, p < 0.001). No correlation was observed between mean difference in eGFR and HIV viral load (r = -0.15, p = 0.2). Independent of the equation used, a significant decrease of eGFR in ARV-treated in comparison to ARV-untreated HIV-1-infected patients was seen (p < 0.001). In conclusion, in HIV-1-infected subjects, especially in ARV-naive men with well-preserved kidney function, eGFR measured by MDRD and CKD-EPI formulas varies strongly following the method used. Such discrepancies may be important in everyday clinical practice and must be confirmed by additional studies using GFR measured with a reference method.

Cardiovascular risk assessment for persons living with HIV

Systematic assessment of cardiovascular risk among persons living with HIV (PLWH) has become more important as HIV survival has increased. Since the advent of effective antiretroviral therapy (ART), PLWH often enjoy life expectancies equal to those of the general population. PLWH then share the same comorbidities as the general population, with some increased risks due to HIV and ART. One comorbidity, cardiovascular disease, is the leading cause of death in the United States. As the current population of PLWH ages, reducing cardiovascular risk will become even more important. Before cardiovascular risk reduction can take place, providers must first know the patient's risks. This paper describes the importance of cardiovascular risk assessment for PLWH based on current literature and presents findings from a quality-improvement (QI) initiative designed to implement systematic cardiovascular assessment using the Framingham Risk (FR) for PLWH in an infectious-disease practice.

Risk factors of chronic kidney disease in HIV-infected patients

BACKGROUND AND OBJECTIVES

The main aim of this study was determining the risk factors of chronic kidney disease (CKD) in HIV-1-infected patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients were followed from seven large HIV reference centers in France that maintain prospective databases on HIV-1-infected patients. The main outcome was the time to CKD defined as two consecutive measures of estimated GFR ≤60 ml/min per 1.73 m² over ≥3 months. A Cox's model with delayed entry was used to search predictive factors of time to CKD.

RESULTS

From 1993 to 2006, 349 out of 7378 patients were found to have CKD. Of these, 166 had hypertension, 33 had diabetes, and 26 were antiretroviral therapy-naïve. Occurrence of acute kidney injury (hazard ratio [HR] = 2.40) and hypertension (HR = 2.39) were strongly associated with an increased risk of CKD. Patients with a durable level of CD4 count >200 cells/mm³ had a lower risk of CKD (HR = 0.63). Recent exposure to indinavir (HR = 2.03), totenofovir (HR = 1.55), and abacavir (HR = 1.37) were associated with an increased risk of CKD. Past exposure to tenofovir was also associated with an increased risk of CKD (HR = 2.23), and a trend toward significance was observed for past exposure to indinavir (HR = 1.28).

CONCLUSIONS

CKD was not rare in HIV-infected patients and occurs preferentially in HIV-infected patients exposed to certain ARVs, specifically abacavir, indinavir and tenofovir. This requires closer monitoring of renal function in patients exposed to one of these drugs.

Biomarkers of impaired renal function

PURPOSE OF REVIEW

Renal disease is increasingly common as life expectancy of HIV-infected persons continues to improve. Several biomarkers are available for monitoring renal function, although no consensus exists on how best to apply these tools in HIV infection. This review describes recent findings for the more common renal biomarkers.

RECENT FINDINGS

Although widely used in clinical practice, creatinine-based estimates of glomerular filtration rate have not been validated in HIV infection. Serum cystatin C has been proposed as a more sensitive marker of renal dysfunction in HIV infection, although it may also reflect systemic inflammation. Screening for proteinuria and albuminuria allows identification of patients at higher risk of kidney disease and other adverse outcomes. Fanconi syndrome, which has been associated with tenofovir use, is associated with severe tubular proteinuria, and several low molecular weight proteins, including retinol-binding protein, β2-microglobulin, and neutrophil gelatinase-associated lipocalin have been studied as markers of tubular dysfunction. Studies have reported a high prevalence of subclinical proximal tubular dysfunction in patients receiving antiretroviral therapy.

SUMMARY

Future studies are needed to determine the optimal biomarkers for the detection and monitoring of renal disease in HIV.

HIV Infection, Antiretroviral Therapy and Cardiovascular Risk

In the last 15 years, highly active antiretroviral therapy (HAART) has determined a dramatic reduction of both morbidity and mortality in human immunodeficiency virus (HIV)-infected subjects, transforming this infection in a chronic and manageable disease. Patients surviving with HIV in the developed world, in larger number men, are becoming aged. As it would be expected for a population of comparable age, many HIV-infected individuals report a family history of cardiovascular disease, a small proportion have already experienced a cardiovascular event and an increasing proportion has diabetes mellitus. Smoking rate is very high while an increasing proportion of HIV-infected individuals have dyslipidaemia. Studies suggest that these traditional risk factors could play an important role in the development of cardiovascular disease in these patients as they do in the general population. Thus, whilst the predicted 10-year cardiovascular disease risk remains relatively low at present, it will likely increase in relation to the progressive aging of this patient population. Thus, the long-term follow-up of HIV infected patients has to include co-morbidity management such as cardiovascular disease prevention and treatment. Two intriguing aspects related to the cardiovascular risk in patients with HIV infection are the matter of current investigation: 1) while these subjects share many cardiovascular risk factors with the general population, HIV infection itself increases cardiovascular risk; 2) some HAART regimens too influence atherosclerotic profile, partly due to lipid changes. Although the mechanisms involved in the development of cardiovascular complications in HIV-infected patients remain to be fully elucidated, treatment guidelines recommending interventions to prevent cardiovascular disease in these individuals are already available; however, their application is still limited.

Premature onset of cardiovascular disease in HIV-infected individuals: the drugs and the virus

Life expectancy in HIV-infected individuals has been greatly enhanced through immunologic restoration and virologic suppression resulting from antiretroviral therapy. Current clinical HIV care in Western countries focuses on treatment of drug toxicities and prevention of comorbidities. These non-AIDS HIV-related comorbidities, such as cardiovascular disease, occur even in individuals with virologic suppression and manifest at an earlier age than when normally presenting in the general population. While traditional risk factors are present in many HIV-infected individuals who develop cardiovascular disease, the additional roles of HIV-related chronic inflammation and immune activation as well as chronic HIV viremia may be significant. This review provides current evidence for the contributions of the virus, in terms of both chronic viremia and its contribution via chronic low-level inflammation, immune activation, premature immune senescence and dyslipidemia, to the pathogenesis of HIV-related cardiovascular disease, and balances this against the propensity of specific antiretroviral therapies to cause cardiovascular disease, in particular through altered cholesterol metabolism.

Randomized comparison of renal effects, efficacy, and safety with once-daily abacavir/lamivudine versus tenofovir/emtricitabine, administered with efavirenz, in antiretroviral-naive, HIV-1-infected adults: 48-week results from the ASSERT study

BACKGROUND

Abacavir/lamivudine and tenofovir/emtricitabine fixed-dose combinations are commonly used first-line antiretroviral therapies, yet few studies have comprehensively compared their safety profiles.

METHODS

Forty-eight-week data are presented from this multicenter, randomized, open-label study comparing the safety profiles of abacavir/lamivudine and tenofovir/emtricitabine, both administered with efavirenz, in HLA-B*5701-negative HIV-1-infected adults.

RESULTS

Three hundred eighty-five subjects were enrolled in the study. The overall rate of withdrawal was high (28%). Changes in estimated glomerular filtration rate from baseline were similar between arms [difference 0.953 mL.min.1.73 m (95% confidence interval: -1.445 to 3.351), P = 0.435]. Urinary excretion of retinol-binding protein and beta-2 microglobulin increased significantly more in the tenofovir/emtricitabine arm (+50%; +24%) compared with the abacavir/lamivudine arm (no change; -47%) (P < 0.0001). A lower proportion achieved viral load <50 copies per milliliter in the abacavir/lamivudine arm (114 of 192, 59%) compared with the tenofovir/emtricitabine arm (137 of 193, 71%) [difference 11.6% (95% confidence interval: 2.2 to 21.1)]. The overall virological failure rate was low. The adverse event rate was similar between arms (except drug hypersensitivity, reported more in the abacavir/lamivudine arm).

CONCLUSIONS

The study showed no difference in estimated glomerular filtration rate between the arms, however, increases in markers of tubular dysfunction were observed in the tenofovir/emtricitabine arm, the long-term consequence of which is unclear. A significant difference in efficacy favoring tenofovir/emtricitabine was observed.

Immunodeficiency and renal impairment are risk factors for HIV-associated acute renal failure

OBJECTIVE

To identify risk factors for acute renal failure (ARF) in HIV-infected patients.

DESIGN

Observational cohort study of HIV-infected patients attending a South London HIV centre between January 1999 and December 2008.

METHODS

ARF was defined as a transient, more than 40% reduction in renal function as assessed by estimated glomerular filtration rate. Multivariate Poisson regression analysis was used to identify baseline and time-updated factors associated with ARF.

RESULTS

The incidence of ARF was 2.8 (95% confidence interval 2.41-3.24) episodes per 100 person-years. We observed a stepwise increase in ARF incidence with time accrued at lower CD4 cell count and at lower estimated glomerular filtration rate, with adjusted incidence rate ratios of 1 (reference), 1.56 (0.97-2.48), 2.08 (1.11-3.91), 6.38 (3.18-12.78) and 10.29 (5.11-20.98) for CD4 cell counts of more than 350, 201-350, 101-200, 51-100 and of 50/microl or less, and 1 (reference), 1.46 (0.86-2.51), 4.19 (2.37-7.42) and 27.00 (16.13-44.95) for estimated glomerular filtration rate more than 90, 75-89, 60-74 and less than 60 ml/min, respectively. Ethnicity, hepatitis B or C coinfection, exposure to combination antiretroviral therapy with or without indinavir, tenofovir or atazanavir and HIV viraemia were not associated with ARF.

CONCLUSION

Current levels of immunodeficiency and renal function were independent predictors of HIV-associated ARF.

Recent developments in HIV-related kidney disease

Although kidney disease has been a recognized complication of HIV infection since the beginning of the HIV epidemic, its epidemiology, underlying causes and treatment have evolved in developed countries where HAART has been widely available. HIV-associated nephropathy and HIV immune complex-mediated kidney disease were the prominent renal diagnoses in the earlier period of the HIV epidemic. While HIV immune complex-mediated kidney disease remains a common finding among HIV-infected individuals with kidney disease, the incidence of HIV-associated nephropathy has been diminishing in developed countries. The role of the metabolic effects of long-term HAART exposure and nephrotoxicity of certain antiretroviral medications on the development and progression of chronic kidney disease is now of increasing concern. The long-term clinical implications of acute kidney injury among HIV-infected persons are increasingly recognized. Kidney disease in HIV-infected persons continues to be a major risk factor for morbidity and mortality in this patient population; therefore, early recognition and treatment of kidney disease are imperative in lessening the impact of kidney disease on the health of HIV-infected individuals. This review focuses on recent developments and ongoing challenges in the understanding, diagnosis and management of HIV-related kidney disease.