Antiretroviral therapy in the treatment of HIV-associated nephropathy

HIV-associated nephropathy patients with and without apolipoprotein L1 gene variants have similar clinical and pathological characteristics

Recently, an association was found between non-diabetic kidney disease in African Americans and two independent sequence variants in the APOL1 gene, encoding apolipoprotein L1. In this study we determined the frequency of APOL1 risk variants in patients with biopsy-proven HIV-associated nephropathy (HIVAN) and distinctive pathological characteristics potentially driven by those risk variants. Among 76 patients with HIVAN, 60 were successfully genotyped for APOL1 G1 and G2 polymorphisms. In this cohort, 37 had two risk alleles, 18 were heterozygous and 5 had neither risk variant. There were no differences in the pathological findings of HIVAN and the number of APOL1 risk alleles. Further, the progression to end stage kidney disease or death did not differ by the number of risk alleles. Median renal survival was 9.3 months in patients with none or one risk allele compared to 11.7 months in patients with two APOL1 risk alleles. Thus, our study suggests that although the majority of African American patients with HIVAN have two APOL1 risk alleles, other as yet unknown factors in the host including genetic risk variants and environmental or viral factors may influence the development of this disorder in those with none or one APOL1 risk allele.

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.

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.

Very late initiation of HAART impairs treatment response at 48 and 96 weeks: results from a meta-analysis of randomized clinical trials

BACKGROUND

Initiation of highly active antiretroviral therapy (HAART) with low CD4 lymphocyte counts is associated with AIDS-related and non-AIDS-related events and increased mortality. However, no clear association has been found with an increased rate of treatment failure.

METHODS

We conducted a meta-analysis including randomized clinical trials of currently recommended HAART in naive patients to evaluate treatment response in very late starters (VLSs). Studies with information on response in at least one of the two strata (≤ 50 versus >50 CD4 cells/mm(3) and/or ≤ 200 versus >200 CD4 cells/mm(3)) and follow-up of at least 48 weeks were analysed. A pooled odds ratio of the effect of starting HAART with ≤ 50 versus >50 or ≤ 200 versus >200 CD4 cells/mm(3) for each arm by fitting a random-effect logistic regression model was computed. Sources of heterogeneity [sex, age, year of study initiation, nucleos(-t)ide pair and third drug] were investigated.

RESULTS

We included 25 treatment arms from 13 randomized clinical trials. Being a VLS consistently impairs treatment outcomes at 48 and 96 weeks. Only hepatitis C virus (HCV)/hepatitis B virus (HBV) coinfection was associated with a reduced impact of late initiation of HAART; at 48 weeks for 50 and 200 cells/mm(3) thresholds (P = 0.013 and P = 0.032, respectively). None of the remaining sources of heterogeneity explored was significantly associated with the impact of being a VLS.

CONCLUSIONS

We found that initiation of antiretroviral therapy with very low CD4 lymphocyte counts is consistently associated with poorer outcomes of HAART. This effect could be modulated by HBV/HCV coinfection, but not by the individual components of the HAART regimen.

Adverse host factors exacerbate occult HIV-associated nephropathy

In the present study, we hypothesized that HIV-1-induced occult HIV-associated nephropathy (HIVAN) would become apparent in the presence of adverse host factors. To test our hypothesis, Vpr mice (which display doxycycline-dependent Vpr expression in podocytes) with two, three, and four copies of the angiotensinogen (Agt) gene (Vpr-Agt-2, Vpr-Agt-3, and Vpr-Agt-4) were administered doxycycline for 3 weeks (to develop clinically occult HIVAN) followed by doxycycline-free water during the next 3 weeks. Subsequently, renal biomarkers were measured, and kidneys were harvested for renal histology. Vpr-Agt-2 developed neither proteinuria nor elevated blood pressure, and displayed minimal glomerular and tubular lesions only, without any microcyst formation. Vpr-Agt-3 showed mild glomerular and tubular lesions and microcyst formation, whereas Vpr-Agt-4 showed moderate proteinuria, hypertension, glomerular sclerosis, tubular dilation, microcysts, and expression of epithelial mesenchymal transition markers. Vpr-Agt-4 not only displayed enhanced renal tissue expression of Agt, renin, and angiotensin-converting enzyme, but also had higher renal tissue concentrations of angiotensin II. Moreover, renal cells in Vpr-Agt-4 showed enhanced expression of transforming growth factor-β, connective tissue growth factor, and vascular endothelial growth factor. These findings indicate that adverse host factors, such as the activation of the renin-angiotensin system, promote the progression of occult HIVAN to apparent HIVAN.

Presentation of HIV-associated nephropathy and outcome in HAART-treated patients

BACKGROUND

Among the numerous renal diseases observed in human immunodeficiency virus (HIV) patients, HIV-associated nephropathy (HIVAN) is a major cause of end-stage renal disease (ESRD). The purpose of our study was to describe the presentation and outcome of HIVAN in the era of highly active antiretroviral therapy (HAART).

METHODS

We analysed clinical features and outcome of 57 patients with histologically proven HIVAN diagnosed between 2000 and 2009 in four teaching hospitals in Paris, France.

RESULTS

This series was characterized by median age of 41 years (18-58), frequent African origin (87%), severe renal dysfunction [estimated glomerular filtration rate (eGFR) 20 mL/min/1.73m(2) (1-68)], high-grade proteinuria [4.1 g/day (0.6-16.8)], high proportion of sclerotic glomeruli [31.5% (0-95)], high HIV load [4.5 log copies/mL (0-6.7)] and low CD4+ count [127/mm(3) (3-713)]. Nevertheless, a non-negligible proportion of patients did not present with these typical features. Follow-up data were available for 51 patients. ESRD occurred in 30 patients (58.8%). Median renal survival was 40 months. Baseline characteristics significantly associated with ESRD were as follows: severity of renal dysfunction, percentage of sclerotic glomeruli, time from HIV infection to HIVAN diagnosis longer than 1 year and prior exposure to antiretroviral drugs. There was an insignificant trend towards better renal outcome being associated with viral suppression during follow-up. Use of renin-angiotensin system (RAS) blockers was associated with higher renal survival (P < 0.05).

CONCLUSION

Despite HAART, HIVAN led to ESRD in more than half of the cases. Early recognition of the disease is crucial to start HAART and RAS blockers before irreversible renal injury.

Management of HIV infection in treatment-naive patients: a review of the most current recommendations

PURPOSE

The most current guidelines issued by the Department of Health and Human Services (DHHS) on the management of human immunodeficiency virus (HIV) infection in treatment-naive patients are reviewed.

SUMMARY

Treatment guidelines are updated frequently because of the emergence of data demonstrating the risks and benefits of antiretroviral therapy. The DHHS guidelines strongly recommend initiating therapy in patients with certain conditions regardless of CD4 cell count and in patients with CD4 cell counts of <350 cells/mm(3). Although supporting data are less definitive, treatment is also recommended for patients with CD4 cell counts of 350-500 cells/mm(3). Treatment for patients with CD4 cell counts of >500 cells/mm(3) is controversial. Although cumulative observational data and biological evidence support treatment at higher CD4 cell counts, randomized controlled trial data to support this are not available, and the risk of antiretroviral toxicities, resistance, non-adherence, and cost should be considered in individual patients. The preferred regimens have been consolidated to four options, including a dual-nucleoside reverse transcriptase inhibitor backbone (tenofovir plus emtricitabine) with a nonnucleoside reverse transcriptase inhibitor (efavirenz), a ritonavir-boosted protease inhibitor (atazanavir plus ritonavir or darunavir plus ritonavir), or an integrase strand-transfer inhibitor (raltegravir). Regimens are classified as alternative or acceptable when they have potential safety or efficacy concerns, have higher pill burdens, or require more-frequent administration compared with preferred regimens.

CONCLUSION

The DHHS 2011 guidelines advocate earlier antiretroviral therapy initiation than recommended in recent years, and preferred regimens have been refined to maximize efficacy, safety, and quality of life for treatment-naive HIV-infected patients.

Acute dialysis in HIV-positive patients in Cape Town, South Africa

AIM

The prognosis for HIV patients needing acute dialysis is uncertain. The aim of this study was to describe the clinical presentation, renal diagnoses and outcomes of HIV patients who underwent acute haemodialysis at Groote Schuur Hospital in the period 2002-2007.

METHODS

A retrospective review of case records of HIV patients who underwent acute haemodialysis was conducted.

RESULTS

One hundred and seventeen patients were reviewed (median age 34.0 years (29.0-40.0) 53.8% men, 93.2% black Africans) and 33 had a renal biopsy. Acute tubular necrosis (ATN) was diagnosed in 68 patients. Recovery of renal function occurred in 33.3% of all patients while in 25.7% treatment was withdrawn and 41.0% died in hospital. Suspected ATN was the commonest cause of renal disease in those who recovered renal function (82.1%). A higher CD4 count (odds ratio (OR)=0.994, P=0.007), lower pre-dialysis serum creatinine (<1230 µmol/L) and longer hospitalization (OR=0.93, P=0.006) significantly correlated with survival.

CONCLUSION

There is a good chance of survival for HIV patients needing acute dialysis when the diagnosis is ATN, and when the CD4 count is more than 200 cells/mm3.

Treatment of HIV-associated nephropathies

In patients with HIV, the use of highly active antiretroviral therapy has improved life expectancy. At the same time, this increase in life expectancy has been associated with a higher frequency of chronic kidney disease due to factors other than HIV infection. Besides HIV-associated nephropathy, a number of different types of immune complex and non-immune complex-mediated processes have been identified on kidney biopsies, including vascular disease (nephrosclerosis), diabetes, and drug-related renal injury. In this setting, renal biopsy needs to be considered in order to obtain the correct diagnosis in individual patients with HIV and kidney impairment. Many issues regarding the optimal treatment of the different pathological processes affecting the kidneys of these patients have remained unresolved. Further research is needed in order to optimize treatment and renal outcomes in patients with HIV and kidney disease.

Expert opinion on pharmacotherapy of kidney disease in HIV-infected patients

INTRODUCTION

Human immunodeficiency virus (HIV) infection is associated with the development of a wide spectrum of kidney diseases. HIV-associated nephropathy (HIVAN) is the most common cause of chronic kidney disease (CKD) in HIV-infected individuals and predominantly affects patients of African ancestry. HIVAN is a leading cause of end-stage renal disease (ESRD) among African-Americans.

AREAS COVERED

An overview of the spectrum of kidney disease in patients with HIV is given. Current pharmacologic interventions to treat kidney disease in HIV are discussed. This review will enhance knowledge regarding the most common causes of kidney disease in HIV-infected patients. An understanding of the principles related to pharmacotherapy in HIV-infected patients with kidney disease will also be gained.

EXPERT OPINION

Kidney disease is an important cause of morbidity and mortality in HIV-infected patients. The most common cause of chronic kidney disease in this population is HIV-associated nephropathy, which is caused by viral infection of the renal epithelium. Several medications that are commonly used in HIV-infected patients can have adverse effects on the kidneys and the doses of many antiretroviral medications need to be adjusted in patients with impaired renal function.

Renal transplantation in HIV-infected patients: 2010 update

The prognosis of human immunodeficiency virus (HIV) infection has improved in recent years with the introduction of antiretroviral treatment. While the frequency of AIDS-defining events has decreased as a cause of death, mortality from non-AIDS-related events including end-stage renal diseases has increased. The etiology of chronic kidney disease is multifactorial: immune-mediated glomerulonephritis, HIV-associated nephropathy, thrombotic microangiopathies, and so on. HIV infection is no longer a contraindication to transplantation and is becoming standard therapy in most developed countries. The HIV criteria used to select patients for renal transplantation are similar in Europe and North America. Current criteria state that prior opportunistic infections are not a strict exclusion criterion, but patients must have a CD4+ count above 200 cells/mm(3) and a HIV-1 RNA viral load suppressible with treatment. In recent years, more than 200 renal transplants have been performed in HIV-infected patients worldwide, and mid-term patient and graft survival rates have been similar to that of HIV-negative patients. The main issues in post-transplant period are pharmacokinetic interactions between antiretrovirals and immunosuppressants, a high rate of acute rejection, the management of hepatitis C virus coinfection, and the high cardiovascular risk after transplantation. More studies are needed to determine the most appropriate antiretroviral and immunosuppressive regimens and the long-term outcome of HIV infection and kidney graft.

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.

HIV-1 and kidney cells: better understanding of viral interaction

HIV-associated nephropathy (HIVAN) is the most common disease affecting untreated seropositive patients of African descent. Besides genetic (African descent) and HIV-1 infection (environmental), specific host factors such as activation of renin-angiotensin-aldosterone system (RAAS) have also been demonstrated to play a role in the manifestation of HIVAN. The recent identification of MYH9 as susceptible allele is a key step forward in our understanding for the pathogenesis of focal glomerulosclerosis in people of African-American descent. HIV-1 transgenic models have significantly advanced our knowledge base in terms of role of HIV-1 genes in general and individual gene in particular in the development of renal lesions mimicking HIVAN. These studies suggest that viral replication is not needed for the development of renal lesions. Renal biopsy data from HIVAN patients suggest that renal epithelial cells express HIV-1 genes and thus it may be sufficient to invoke HIVAN phenotype in the presence of specific host and genetic factors. On the other hand, immune response to infection may be required to induce HIV-1 associated immune complex kidney disease (HIVICK). Since renal cell lack conventional HIV-1 receptors, HIV-1 entry into renal cells has been a mystery. Recently, non-conventional pathways have been demonstrated to facilitate HIV-1 entry into renal cells in in vitro studies. These include presence of DEC-205 receptors in renal tubular cells and lipid rafts in podocytes. However, HIV-1 entry through these pathways only allows non-productive infection. It appears that the presence of specific genetic and host factors in in vivo conditions may be facilitating the development of the productive HIV-1 infection in kidney cells.

[Diagnosis, treatment and prevention of renal diseases in HIV infected patients. Recommendations of the Spanish AIDS Study Group/National AIDS Plan]

The incidence of opportunistic infections and tumours in HIV-infected patients has sharply declined in the HAART era. At the same time there has been a growing increase of other diseases not directly linked to immunodeficiency. Renal diseases are an increasing cause of morbidity and mortality among HIV-infected patients. In the general population, chronic renal failure has considerable multiorgan repercussions that have particular implications in patients with HIV infection. The detection of occult or subclinical chronic kidney disease is crucial since effective measures for delaying progression exist. Furthermore, the deterioration in glomerular filtration should prompt clinicians to adjust doses of some antiretroviral agents and other drugs used for treating associated comorbidities. Suppression of viral replication, strict control of blood pressure, dyslipidemia and diabetes mellitus, and avoidance of nephrotoxic drugs in certain patients are fundamental components of programs aimed to prevent renal damage and delaying progression of chronic kidney disease in patients with HIV. Renal transplantation and dialysis have also special implications in HIV-infected patients. In this article, we summarise the updated clinical practice guidelines for the evaluation, management and prevention of renal diseases in HIV-infected patients from a panel of experts in HIV and nephrologists on behalf of the Spanish AIDS Study Group (GESIDA) and the National AIDS Plan.

Association between kidney function and albuminuria with cardiovascular events in HIV-infected persons

BACKGROUND

Cardiovascular disease (CVD) is now a leading cause of death in HIV-infected persons; however, risk markers for CVD are ill defined in this population. We examined the association between longitudinal measures of kidney function and albuminuria with risk of atherosclerotic CVD and heart failure in a contemporary cohort of HIV-infected individuals.

METHODS AND RESULTS

We followed a national sample of 17 264 HIV-infected persons receiving care in the Veterans Health Administration for (1) incident CVD, defined as coronary, cerebrovascular, or peripheral arterial disease, and (2) incident heart failure. Rates of CVD and heart failure were at least 6-fold greater in the highest-risk patients with an estimated glomerular filtration rate (eGFR) <30 mL/min per 1.73 m(2) and albuminuria > or =300 mg/dL versus those with no evidence of kidney disease (eGFR > or =60 mL/min per 1.73 m(2) and no albuminuria). After multivariable adjustment, eGFR levels 45 to 59, 30 to 44, and <30 mL/min per 1.73 m(2) were associated with hazard ratios for incident CVD of 1.46 (95% confidence interval, 1.15 to 1.86), 2.03 (1.47 to 2.82), and 1.99 (1.46 to 2.70) compared with eGFR > or =60 mL/min per 1.73 m(2). Similarly, albuminuria levels 30, 100, and > or =300 mg/dL had hazard ratios for CVD of 1.28 (1.09 to 1.51), 1.48 (1.15 to 1.90), and 1.71 (1.30 to 2.27) compared with absent albuminuria. The associations between eGFR and albuminuria with heart failure were larger in magnitude and followed the same trends.

CONCLUSIONS

In this national sample of HIV-infected persons, eGFR and albuminuria levels were strongly associated with risk of CVD and heart failure. Kidney function and albuminuria provide complementary prognostic information that may aid CVD risk stratification in HIV-infected persons.

Impact of tenofovir on renal function in HIV-infected, antiretroviral-naive patients

OBJECTIVE

To better characterize the long-term effects of tenofovir on renal function in a large managed care organization.

METHODS

We performed a retrospective cohort analysis in Kaiser Permanente for years 2002 to 2005 comparing renal function among antiretroviral naïve patients initiating a tenofovir-containing regimen (964 patients) or tenofovir-sparing regimens (683 patients). We evaluated glomerular filtration rate (GFR, [Modification of Diet in Renal Disease equation]), serum creatinine, and the development of renal proximal tubular dysfunction. We report multivariable hazard ratios (HR, Cox modeling) and linear outcomes (repeated measures) with predictors retained if P < 0.10 (backward selection). Potential predictor variables included in multivariate models were age, sex, Black race, baseline laboratories (including CD4 count), history of diabetes mellitus, hypertension, malignancy, hepatitis, and concurrent medications.

RESULTS

Overall, tenofovir-exposed patients had a larger relative decline in GFR through 104 weeks (-7.6 mL/min/1.73 m(2) relative to tenofovir-sparing, P < 0.001); the degree of the difference varied by baseline GFR, with the greatest effect seen in those patients with GFR greater than 80 mL/min/1.73 m(2). Tenofovir-exposed patients had greater development of proximal tubular dysfunction over time (at 52 wk: HR(adjusted) = 1.95 [P = 0.01] and at 104 wk: HR(adjusted) = 5.23 [P = 0.0004]) and had greater risk of medication discontinuation (HR(adjusted) = 1.21, P = 0.02), especially as renal function worsened. Viral control and CD4 count changes were similar between the two groups.

CONCLUSIONS

Tenofovir is associated with greater effect on decline in renal function and a higher risk of proximal tubular dysfunction in antiretroviral naïve patients initiating antiretroviral therapy.

HIV and CKD epidemiology

Nephrologists can serve many important functions for HIV-infected patients, including identifying risks for developing kidney disease, detecting and diagnosing kidney disease, distinguishing antiretroviral-induced kidney injury from kidney disease in the setting of antiretroviral therapy, comanaging the clinical course and complications of CKD, and preparing patients for dialysis and/or transplantation. The epidemiology of kidney disease in HIV informs us for these functions by describing the natural history of disease, its frequent occurrence in high-risk communities, and its potential causes. Risk factors that drive CKD in HIV are black race, hypertension, diabetes, HIV viral replication with low CD4 cell counts, high viral load or acquired immune deficiency syndrome-defining conditions, and antiretroviral agents with nephrotoxic potential. The prevalence of these risk factors in any population determines the magnitude of the problem, which can range from as low as 2% to as high as 30%. Recent research focuses on kidney health in HIV. Important links between HIV viral replication and glomerular filtration rate, even in patients with normal kidney function, are now being reported. A review of these data provides the foundation for a better understanding of kidney disease and, hopefully, better treatment for patients with HIV.

Diagnosis and natural history of HIV-associated nephropathy

HIV-associated nephropathy (HIVAN) is a largely distinctive phenotype induced by HIV-1 infection and is the most recognized and detrimental kidney disease in HIV-infected patients. Host and viral characteristics have been implicated in the pathogenesis of HIVAN that may explain its exclusive predilection to patients of African descent. In untreated patients, the disorder is clinically manifested by an acute decline in kidney function, most often in conjunction with high-grade proteinuria and uncontrolled HIV-1 infection. Histologically, proliferating glomerular epithelial cells are the prominent feature of the disease. Data have evolved over the past decade suggesting that highly active antiretroviral therapy (HAART) can change the natural history of HIVAN, not only by preventing its development but also by halting its progression once developed. Consequently, with the widespread use of HAART, the prevalence of HIVAN is declining in Western countries. In contrast, the epidemiology of the disease is not well defined in the poorest areas in the world, which bear a disproportionate share of the HIV-1 epidemic's burden. Corticosteroids and inhibition of the renin-angiotensin axis are recommended as adjunctive agents in treating patients with established HIVAN and are potentially helpful in delaying the need for renal replacement therapy. However, the long-term value and potential risks of using corticosteroids in this population are unclear.

Gene-gene and gene-environment interactions in HIV-associated nephropathy: A focus on the MYH9 nephropathy susceptibility gene

HIV-associated nephropathy (HIVAN) is a leading cause of ESRD in African Americans. The HIV-1 virus infects podocytes, cells integral to formation of the glomerular filtration barrier, often leading to focal segmental glomerulosclerosis. HIVAN is typically a complication of late-stage HIV infection, associated with low CD4 cell counts and elevated serum HIV RNA levels. Highly active antiretroviral therapy is partially protective and has altered the natural history of HIV-associated kidney disease. Nonetheless, HIVAN remains an important public health concern among HIV-infected African Americans. Although polymorphisms in the MYH9 gene on chromosome 22 are strongly associated with HIVAN, as well as with idiopathic focal segmental glomerulosclerosis and global glomerulosclerosis (historically labeled "hypertensive nephrosclerosis"), the majority of HIV-infected patients who are genetically at risk from MYH9 do not appear to develop severe kidney disease. Therefore, we postulate that additional environmental exposures and/or inherited factors are necessary to initiate human HIVAN. Gene-environment interactions have also been proposed as necessary for the initiation of HIVAN in murine models. It is important that these novel risk factors be identified because prevention of environmental exposures and targeting of additional gene products may reduce the risk for HIVAN, even among those harboring 2 risk alleles in MYH9.

Prevalence and factors associated with renal impairment in HIV-infected patients, ANRS C03 Aquitaine Cohort, France

OBJECTIVES

The aims of the present study were to estimate the prevalence of renal impairment (RI) among HIV-infected adult patients and to investigate the associated factors.

METHODS

A cross-sectional survey was conducted in a French hospital-based cohort. Clearance of creatinine (CC) was calculated using the Cockcroft-Gault formula. Four stages of RI were defined: mild (60-90 mL/min), moderate (30-60), severe (15-30) and end stage (<15). Logistic regression models were used to investigate factors associated with RI.

RESULTS

The male/female ratio of the 2588 patients enrolled was 3:1 and the median age was 42 years. At the time of assessment of CC, the median CD4 count was 430 cells/microL and HIV plasma viral load (VL) was<50 copies/mL in 60%. The overall prevalence of RI was 39.0%: 34.2% mild, 4.4% moderate, 0.3% severe and 0.2% end-stage. Mild RI was associated with female gender [odds ratio (OR)=3.3: 95% CI 2.6-4.3)], age >50 years (OR=9.8: 7.4-13.0) and 40-50 years (OR=1.9: 1.5-2.4), body mass index (BMI) <22 kg/m(2) (OR=3.3: 2.7-4.3) and tenofovir exposure (OR=1.4: 1.0-1.9 for <1 year and OR=1.5: 1.2-2.0 for >1 year). Advanced RI (CC <60 mL/min) was associated with age >50 years (OR=5.6: 2.9-10.9) and 40-50 years (OR=2.2: 1.1-1.4), BMI <22 kg/m(2) (OR=1.5: 1.0-2.4), hypertension (OR=2.5: 1.4-2.5) and indinavir (IDV) exposure >1 year (OR=2.3: 1.5-3.6).

CONCLUSION

This survey confirms the high prevalence of RI in HIV-infected patients and indicates the importance of the investigation of renal function especially in women, older patients, those with a low BMI or treated with tenofovir or IDV.

Clinical epidemiology of HIV-associated end-stage renal failure in the UK

OBJECTIVE

To describe the clinical epidemiology of HIV-associated end-stage renal failure (HIV/ESRF) from 1998 to 2007 in the United Kingdom.

DESIGN

Observational cohort study.

SETTING

Seven leading HIV centres and affiliated renal clinics in the United Kingdom.

PARTICIPANTS

A total of 21 951 patients in whom renal function was measured.

MAIN OUTCOME MEASURE

Development of end-stage renal failure (ESRF) as defined by initiation of permanent renal replacement therapy (pRRT).

RESULTS

Sixty-eight (0.31%) patients had HIV/ESRF, 44 (64.7%) of whom were black. The prevalence of ESRF in black patients increased over time from 0.26% in 1998-1999 to 0.92% in 2006-2007 (P for trend = 0.001). Overall 5-year survival from starting pRRT was 70.3%, and significantly better for black patients compared to those of other ethnicities (85.2 vs. 43.4%, P = 0.001). In multivariable analysis, black ethnicity was associated with a higher risk of ESRF [HR 6.93, 95% confidence interval (CI) 3.56, 13.48], whereas a higher current CD4 cell count was associated with reduced risk (HR: 0.83, 95% CI 0.76, 0.95) per 50 cells higher). No association was seen between current viral load or current highly active antiretroviral therapy (HAART) status and ESRF. On the basis of these observations, we estimate that 231 HIV-infected patients required pRRT in the United Kingdom in 2007, and an HIV prevalence of 0.51% among the United Kingdom pRRT recipients in that year.

CONCLUSION

The prevalence of HIV/ESRF increased during the HAART era to reach nearly 1% in black patients, in whom favourable survival rates were observed. Earlier HIV diagnosis will be an important strategy to stem the rising trend of HIV/ESRF.

HIV-infected persons continue to lose kidney function despite successful antiretroviral therapy

OBJECTIVE

To identify risk factors associated with kidney function decline in a contemporary cohort of treated and untreated HIV-infected patients.

METHODS

We followed individuals enrolled in the Study of the Consequences Of the Protease inhibitor Era cohort for longitudinal changes in kidney function, defined as glomerular filtration rate estimated from serum creatinine (eGFR). eGFR slope was calculated using linear mixed effects models adjusted for age, sex, race, and time-updated CD4 cell count, viral load, antiretroviral therapy (ART), and comorbid conditions.

RESULTS

We followed 615 patients for a mean of 3.4 (+/- 2.5) years. In multivariable adjusted analyses, predictors of eGFR decline included female sex, diabetes, and hyperlipidemia; CD4 cell count and viral load were not associated with eGFR loss. Among patients who initiated treatment, antiretroviral exposure was associated with a +2.8 (95% confidence interval 0.8-4.7) ml/min per 1.73 m per year effect on eGFR slope. Although these patients appeared to benefit from ART based on the slowing of their eGFR decline, they continued to lose kidney function at a rate of -1.9 (95% confidence interval -3.7 to -0.1) ml/min per 1.73 m per year. In the subgroup of individuals receiving suppressive ART with viral loads maintained below 500 copies/ml, intermittent viremic episodes (blips) were strongly associated with more rapid rates of eGFR loss [-6.7 (95% confidence interval -11.1 to -2.4) ml/min per 1.73 m per year].

CONCLUSION

Although ART appears to help curb kidney function decline, patients who achieved durable viral suppression continue to manifest substantial loss of eGFR. Loss of kidney function may be attributable to treatment-related factors, intermittent viremia, and traditional risk factors for kidney disease.

Interventions for HIV-associated nephropathy

BACKGROUND

Human immunodeficiency virus associated nephropathy (HIVAN) is the most common cause of end stage kidney disease (ESKD) in Human immunodeficiency virus-1 (HIV-1) serotype patients and it mostly affects patients of African descent. It rapidly progresses to ESKD if untreated. The goal of treatment is directed toward reducing HIV-1 replication and/or slowing the progression of chronic kidney disease. The following pharmacological agents have been used for the treatment of HIVAN: antiretrovirals, angiotensin-converting enzyme inhibitors (ACEi), steroids and recently cyclosporin. Despite this, the effect of each intervention is yet to be evaluated.

OBJECTIVES

To evaluate the benefits and harms of adjunctive therapies in the management of HIVAN and its effects on symptom severity and all-cause mortality.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Renal Group's specialised register, MEDLINE, EMBASE, AIDSearch, reference lists of articles and conference proceedings without language restrictions. We searched the international clinical trials registry platform search portal and also contacted individual researchers, research organisations and pharmaceutical companies that manufacture the drugs used for interventions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any therapy used in the treatment of HIVAN.

DATA COLLECTION AND ANALYSIS

We independently screened the search outputs for relevant studies and to retrieve full articles when necessary. We applied the inclusion criteria to identify four relevant ongoing studies, one is ongoing while the remaining two have completed recruitment and are yet to be published. The fourth study was suspended for an unknown reason.

MAIN RESULTS

No completed RCTs or quasi-RCTs were identified to be included in the study.

AUTHORS' CONCLUSIONS

There is no RCT-based evidence upon which to base guidelines for the treatment of HIVAN. However, steroids and ACEI appear to improve the kidney function of patients in the observational studies that were identified. This review highlights the need for good quality RCTs to address the effects of interventions for treating this group.

Hepatitis C seropositivity and kidney function decline among women with HIV: data from the Women's Interagency HIV Study

BACKGROUND

How coinfection with hepatitis C virus (HCV) impacts on the trajectory of kidney function in human immunodeficiency virus (HIV)-infected patients is unclear. This study examined the effect of HCV infection on kidney function over time in women infected with HIV.

STUDY DESIGN

Retrospective observational cohort.

SETTING & PARTICIPANTS

Study sample included participants from the Women's Interagency HIV Study who were HIV infected and had undergone HCV antibody testing and serum creatinine measurement at baseline.

PREDICTOR

HCV seropositivity.

OUTCOMES & MEASUREMENT

Estimated glomerular filtration rate (eGFR) calculated from semi-annual serum creatinine measurements using the 4-variable Modification of Diet in Renal Diseases (MDRD) Study equation. Linear mixed models were used to evaluate the independent effect of HCV seropositivity on eGFR over time, adjusting for demographic factors, comorbid conditions, illicit drug use, measures of HIV disease status, use of medications, and interactions with baseline low eGFR (<60 mL/min/1.73 m(2)).

RESULTS

Of 2,684 HIV-infected women, 952 (35%) were found to be HCV seropositive. In 180 women with chronic kidney disease (CKD) at baseline (eGFR < 60 mL/min/1.73 m(2)), HCV seropositivity was independently associated with a fully adjusted net decrease in eGFR of approximately 5% per year (95% confidence interval, 3.2 to 7.2) relative to women who were seronegative. In contrast, HCV infection was not independently associated with a decrease in eGFR in women without low eGFR at baseline (P < 0.001 for interaction).

LIMITATIONS

The MDRD Study equation has not been validated as a measure of GFR in persons with HIV or HCV infection. Proteinuria was not included in the study analysis. Because the study is observational, effects of residual confounding cannot be excluded.

CONCLUSIONS

In HIV-infected women with CKD, coinfection with HCV is associated with a modest, but statistically significant, decrease in eGFR over time. More careful monitoring of kidney function may be warranted for HIV-infected patients with CKD who are also coinfected with HCV.

Spectrum of chronic kidney disease in HIV-infected patients

OBJECTIVES

The aim of the study was to investigate the prevalence and aetiology of chronic kidney disease (CKD) and trends in estimated glomerular filtration rate (eGFR) in HIV-infected patients.

METHODS

Ascertainment and review of CKD cases among patients attending King's College and Brighton Hospitals, UK were carried out. CKD was defined as eGFR <60 mL/min for > or =3 months. Longitudinal eGFR slopes were produced to examine trends in renal function before, during and after exposure to indinavir (IDV) or tenofovir (TFV).

RESULTS

CKD prevalence was 2.4%. While HIV-associated nephropathy accounted for 62% of CKD in black patients, 95% of CKD in white/other patients was associated with diabetes mellitus, hypertension, atherosclerosis and/or drug toxicity. Exposure to IDV or TFV was associated with an accelerated decline in renal function (4.6-fold and 3.7-fold, respectively) in patients with CKD. In patients initiating IDV, age > or =50 years increased the odds of CKD [odds ratio (OR) 4.9], while in patients initiating TFV, age > or =50 years (OR 5.4) and eGFR 60-75 mL/min (OR 17.2) were associated with developing CKD.

CONCLUSION

This study highlights the importance of metabolic and vascular disease to the burden of CKD in an ageing HIV-infected cohort. In patients who developed CKD, treatment with IDV or TFV was associated with an accelerated decline in renal function.

Antiretroviral nephrotoxicities

With the introduction of combination antiretroviral therapy, there have been substantial declines in both morbidity and mortality associated with human immunodeficiency virus (HIV)-1 infection. However, data increasingly indicate that HIV-1-infected individuals are faced with accelerated rates of chronic diseases that afflict the general population such as diabetes mellitus, hypertension, and dyslipidemia, as well as cardiovascular, liver, and kidney diseases. Furthermore, this population is exposed to a variety of adverse effects from long-term use of antiretroviral medications, which may cause clinically important renal toxicities. However, it often is challenging to distinguish antiretroviral-related renal toxicity from either direct effects of HIV-1 on the kidney or from a multitude of non-HIV-related kidney diseases. A timely and coordinated effort by the HIV primary provider and a nephrologist is likely to facilitate the evaluation of HIV-1-infected patients with new kidney problems.

Fluvastatin prevents podocyte injury in a murine model of HIV-associated nephropathy

BACKGROUND

Recent studies have reported that statins have renoprotective effects, independent from lowering plasma cholesterol. In this study, we examined whether statins were beneficial in a murine model of HIV-associated nephropathy (HIVAN).

METHODS

We used conditional transgenic mice that express one of the HIV-1 accessory genes, vpr, selectively in podocytes using podocin promoter and the Tet-on system. These mice develop aggressive collapsing focal segmental glomerular sclerosis with massive proteinuria and deterioration of renal function within 4 weeks following heminephrectomy and doxycycline administration. Fluvastatin was administrated simultaneously with doxycycline, and the effect was compared with untreated controls after 4 weeks.

RESULTS

Fluvastatin at 10 mg/kg/day significantly decreased urinary albumin excretion (87 versus 11 mg/day, P < 0.01) and glomerular sclerosis (2.4 versus 1.0, P < 0.01, assessed by semi-quantitative scoring: 0-4). Fluvastatin also decreased serum creatinine and total cholesterol, but these differences were not statistically significant (0.36 versus 0.32 mg/dl, P = 0.35; 492 versus 378 mg/dl, P = 0.11, respectively). Phenotypic changes in podocytes, as indicated by the downregulation of nephrin, Wilms' tumour 1 and synaptopodin, along with upregulation of proliferating cell nuclear antigen, were attenuated by fluvastatin, suggesting its protective effects against podocyte injuries. In cultured podocytes, angiotensin II treatment decreased nephrin expression to 13% of basal levels, which was reversed to 58% by adding fluvastatin.

CONCLUSIONS

In conclusion, fluvastatin was effective in treating experimental HIVAN. The beneficial effect of this drug might be caused, in part, by preserving nephrin expression in podocytes against angiotensin II-mediated injury.

Kidney disease in patients with HIV infection and AIDS

As patients infected with human immunodeficiency virus (HIV) live longer while receiving antiretroviral therapy, kidney diseases have emerged as significant causes of morbidity and mortality. Black race, older age, hypertension, diabetes, low CD4(+) cell count, and high viral load remain important risk factors for kidney disease in this population. Chronic kidney disease should be diagnosed in its early stages through routine screening and careful attention to changes in glomerular filtration rate or creatinine clearance. Hypertension and diabetes must be aggressively treated. Antiretroviral regimens themselves have been implicated in acute or chronic kidney disease. The risk of kidney disease associated with the widely used agent tenofovir continues to be studied, although its incidence in reported clinical trials and observational studies remains quite low. Future studies about the relationship between black race and kidney disease, as well as strategies for early detection and intervention of kidney disease, hold promise for meaningful reductions in morbidity and mortality associated with kidney disease.

HIV-associated nephropathy: clinical presentation, pathology, and epidemiology in the era of antiretroviral therapy

The classic kidney disease of human immunodeficiency virus (HIV) infection, HIV-associated nephropathy, is characterized by progressive acute renal failure, often accompanied by proteinuria and ultrasound findings of enlarged, echogenic kidneys. Definitive diagnosis requires kidney biopsy, which shows collapsing focal segmental glomerulosclerosis with associated microcystic tubular dilatation and interstitial inflammation. Podocyte proliferation is a hallmark of HIV-associated nephropathy, although this classic pathology is observed less frequently in antiretroviral-treated patients. The pathogenesis of HIV-associated nephropathy involves direct HIV infection of renal epithelial cells, and the widespread introduction of combination antiretroviral therapy has had a significant impact on the natural history and epidemiology of this unique disease. These observations have established antiretroviral therapy as the cornerstone of treatment for HIV-associated nephropathy in the absence of prospective clinical trials. Adjunctive therapy for HIV-associated nephropathy includes angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, as well as corticosteroids in selected patients with significant interstitial inflammation or rapid progression.

Chronic kidney disease incidence, and progression to end-stage renal disease, in HIV-infected individuals: a tale of two races

BACKGROUND

Little is known about the racial differences in the incidence and progression of HIV-related chronic kidney disease (CKD) that underlie African American-white disparities in HIV-related end-stage renal disease (ESRD).

METHODS

In a cohort in Baltimore, Maryland, we measured CKD incidence, glomerular filtration rate (GFR) slope, and progression to ESRD in 3332 African American and 927 white HIV-infected subjects.

RESULTS

A total of 284 subjects developed CKD, 100 (35%) of whom subsequently developed ESRD. African American subjects were at slightly increased risk for incident CKD, compared with white subjects (hazard ratio [HR], 1.9 [95% confidence interval {CI}, 1.2-2.8]). However, once CKD had commenced, the African American subjects developed ESRD markedly faster than did the white subjects (HR, 17.7 [95% CI, 2.5-127.0]), and, correspondingly, their GFR decline after diagnosis of CKD was 6-fold more rapid (P < .001). In the subset of African American subjects for whom kidney-biopsy data were available, progression to ESRD was significantly faster than that in white subjects with CKD, irrespective of the presence of HIV-associated nephropathy.

CONCLUSIONS

The results of this study suggest that African American-white disparities in HIV-related ESRD are explained predominantly by a more aggressive natural disease history in African Americans and less by racial differences in CKD incidence.

Nephrotoxicity associated with antiretroviral therapy in HIV-infected patients

BACKGROUND

With the success of modern antiretroviral therapies in increasing longevity of patients with HIV infection, chronic conditions including renal disease have assumed a greater importance in patient management. Some antiretroviral therapies have themselves been identified to have clinically significant nephrotoxicity.

OBJECTIVE

To review the risk factors and mechanisms for renal toxicity of antiretroviral drugs, and their impact on the clinical management of patients with HIV.

METHODS

Current literature and HIV treatment guidelines are reviewed.

RESULTS/CONCLUSIONS

Background rates of renal disease and associated risk factors are significant in the HIV clinic population, and renal function should be assessed in all HIV-infected patients. Modern HIV treatment regimens have a relatively low but clinically significant nephrotoxic potential; therefore, renal function should be evaluated on an ongoing basis in patients receiving antiretroviral therapy.

Renal disease in patients with HIV infection: epidemiology, pathogenesis and management

With the introduction of highly active antiretroviral therapy, we have witnessed prolonged survival with the potential for normal life expectancy in HIV-infected individuals. With improved survival and increasing age, HIV-infected patients are increasingly likely to experience co-morbidities that affect the general population, 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, cigarette smoking and injection drug use. Furthermore, they have exposures unique to this population, including antiretrovirals and other medications. Therefore, the differential diagnosis is vast. Early identification (through efficient screening) and definitive diagnosis (by kidney biopsy when indicated) of kidney disease in HIV-infected individuals are critical to optimal management. Earlier interventions with disease-specific therapy, often with the help of a nephrologist, are likely to lead to better outcomes. In those with chronic kidney disease, interventions, such as aggressive blood pressure control with the use of ACE inhibitors or angiotensin receptor antagonists where tolerated, tight blood glucose control in those with diabetes, and avoidance of potentially nephrotoxic medications, can slow progression and prevent end-stage renal disease. Only with greater awareness of kidney-disease manifestations and their implications in this particularly vulnerable population will we be able to achieve success in confronting this growing problem.

Antiretroviral therapy improves renal function among HIV-infected Ugandans

Renal dysfunction is a severe complication of advanced HIV disease. We evaluated the impact of highly active antiretroviral therapy (HAART) on renal function among HIV-infected Ugandans in the Home-Based AIDS Care clinical trial. The patients presented with symptomatic HIV disease or CD4 cell count < or = 250 cells/mm(3) and creatinine clearances above 25 ml/min determined by the Cockcroft-Gault equation. Of the 508 patients at baseline, 8% had a serum creatinine over 133 micromol/l and about 20% had reduced renal function evidenced by a creatinine clearance between 25 and 50 ml/min. After 2 years of HAART, the median serum creatinine was significantly decreased by 16% while the median creatinine clearance significantly increased 21%. The median creatinine clearance of patients with renal dysfunction at baseline, increased by 53% during 2 years of treatment. In multivariable analysis, a baseline creatinine above 133 micromol/l, a weight gain of more than 5 kg over the 2 years, female gender and a WHO stage 4 classification were all associated with greater improvements in creatinine clearance on HAART. Our study shows that renal dysfunction was common with advanced HIV disease in Uganda but this improved following 2 years of HAART.

Proteinuria in children infected with the human immunodeficiency virus

OBJECTIVES

To determine the prevalence of proteinuria in a large cohort of children infected with the human immunodeficiency virus (HIV) and their longitudinal progression during treatment with highly active antiretroviral therapy.

STUDY DESIGN

In a retrospective cohort study, 286 children infected with HIV were monitored with quantitative assays of proteinuria from January 1998 through January 2007, with monitoring of viral load, lymphocyte profiles, kidney function, and mortality rates. Proteinuria was quantitated by urine protein to creatinine ratio (Upr/cr).

RESULTS

Ninety-four (33%) had proteinuria at baseline. Of these, 32 (11.2%) had nephrotic range proteinuria (Upr/cr > or = 1.0). Initial screening was at 11 +/- 0.3 years of age, with an average follow-up of 5.6 +/- 0.1 years. The mortality rate was significantly greater in those with proteinuria. During the period of observation, 15 patients with nephrotic proteinuria died or had development of end-stage renal disease, and 16 showed improvement. Of those with intermediate range proteinuria (Upr/cr > or = 0.2 < 1.0), 3 progressed to nephrotic range proteinuria, and 39 (63%) showed resolution of the proteinuria (Upr/cr < 0.2). Improvement in proteinuria was correlated with decreasing viral load (r = 0.5; P < .01).

CONCLUSIONS

Control of viral load with highly active antiretroviral therapy appears to prevent the progression of HIV-associated renal disease and improve survival rates in infected children.

HIV and the kidney

Kidney disease is an important complication of HIV infection. Antiretroviral therapy has dramatically improved the life expectancy of HIV-infected patients with end-stage renal disease. Renal replacement therapy, including kidney transplantation, should be offered to HIV-positive patients.

Predictors of renal outcome in HIV-associated nephropathy

BACKGROUND

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is an important cause of end-stage renal disease among African American patients. This study was performed to study the epidemiology of HIVAN in a predominantly black African population and the impact of highly active antiretroviral therapy and other factors on the development of end-stage renal disease.

METHODS

We retrospectively identified all patients with HIVAN, defined by biopsy or strict clinical criteria, in 8 clinics in the United Kingdom. Baseline renal function, HIV parameters, renal pathological index of chronic damage, and responses to highly active antiretroviral therapy were analyzed, and factors associated with adverse renal outcome were identified.

RESULTS

From 1998 through 2004, we studied 16,834 patients, 61 of whom had HIVAN. HIVAN prevalence in black patients was 0.93%, and HIVAN incidence in those without renal disease at baseline was 0.61 per 1000 person-years. After a median of 4.2 years, 34 patients (56%) had developed end-stage renal disease. There were no significant differences in renal function and HIV parameters at baseline, time to initiation of highly active antiretroviral therapy, and rates of HIV RNA suppression between the 20 patients who developed end-stage renal disease >3 months after receiving the HIVAN diagnosis and the 23 patients who maintained stable renal function. However, the index of chronic damage score was significantly higher in those who developed end-stage renal disease (P < .001), and an index of chronic damage score >75 was associated with shorter renal survival (P < .001).

CONCLUSIONS

Whereas overall patient survival suggested an important benefit of highly active antiretroviral therapy, no additional renal benefit of early initiation of highly active antiretroviral therapy or viral suppression could be demonstrated in this large cohort of patients with established HIVAN. Severity of chronic kidney damage, as quantified by biopsy, was the strongest predictor of renal outcome.

Survival during renal replacement therapy among African Americans infected with HIV type 1 in urban Baltimore, Maryland

BACKGROUND

African Americans with human immunodeficiency virus type 1 (HIV-1) infection and kidney disease are at increased risk of end-stage renal disease requiring renal replacement therapy (RRT), particularly in urban areas with high rates of poverty and injection drug use. It is unknown how the widespread use of highly active antiretroviral therapy (HAART) has affected survival during RRT in this vulnerable population.

METHODS

African American patients infected with HIV-1 who required RRT were identified from 2 cohorts that included 4509 Africans Americans infected with HIV-1 who were recruited during the period 1988-2004 in Baltimore, Maryland. Survival after initiation of RRT was compared for those who initiated treatment in the pre-HAART and the HAART eras using Kaplan-Meier curves. Cox proportional hazards regression analysis was used to adjust for potential confounders.

RESULTS

RRT was initiated in 162 patients (3.6%) during 10.6 years of follow-up (119 during the HAART era). Compared with patients who started RRT in the pre-HAART era, those in the HAART era were older (P<.001) and more likely to have CD4 cell counts of <or=200 cells/mm(3) (P=.01). A total of 126 patients (78%) died during follow-up; among those who initiated RRT during the HAART era, 87 deaths occurred (73%). Median survival time in the pre-HAART era was 22.4 months (95% confidence interval [CI], 9.3-30.7); during the HAART era, it was 19.9 months (95% CI, 14.7-26.5; P=.94). In the multiple Cox regression model, factors independently associated with increased mortality included age (hazard ratio [HR], 1.30; 95% CI, 1.06-1.60; P=.01), lower serum albumin level (HR, 0.72; 95% CI, 0.57-0.91; P<.007), lower CD4 cell count (HR, 0.90; 95% CI, 0.82-0.99; P<.03), and the lack of HAART (HR, 0.52; 95% CI, 0.33-0.82; P=.005).

CONCLUSIONS

Older age, lower serum albumin level, lower CD4 cell count, and the lack of HAART are independent predictors of poor survival among African Americans infected with HIV-1 undergoing RRT in a resource-limited urban area. RRT survival was similar in the pre-HAART and HAART eras, likely reflecting inadequate HIV treatment in this population.

Observations on a cohort of HIV-infected patients undergoing native renal biopsy

AIMS

This study aims to explore the spectrum of renal disease in HIV-infected patients, identify clinical predictors of HIV-associated nephropathy (HIVAN), and investigate the performance of renal biopsy in HIV-infected patients.

METHOD

Of 263 HIV-infected patients with renal disease evaluated between 1995 and 2004, 152 had a renal biopsy, while 111 had not. A group comparison was performed.

RESULTS

The leading biopsy diagnoses were HIVAN (35%), noncollapsing focal segmental glomerulosclerosis (22%), and acute interstitial nephritis (7.9%), amongst over a dozen others. There was a trend of decreasing yearly incidence of HIVAN diagnoses, paralleling the use of antiretroviral therapy. By multivariate logistic regression, CD4 counts >200 cells/mm(3) and higher estimated glomerular filtration rate were strong negative predictors of HIVAN. HIVAN patients were more likely to require dialysis (p < 0.0001) and had worse overall survival (p = 0.02). Younger age and lower estimated glomerular filtration rate were significant predictors of renal biopsy in multivariate regression analysis. More biopsied patients progressed to dialysis (51 vs. 25%, p = 0.001) and death (15 vs. 5.4%, p = 0.001), despite more frequent corticosteroid treatment (29 vs. 3.6%, p = 0.001).

CONCLUSION

These findings may reflect more severe acute and/or chronic disease at the time of biopsy and suggests that earlier renal biopsy may be warranted in HIV-infected patients, especially in light of the changing spectrum of renal disease in this group.

End-stage renal disease and chronic kidney disease in a cohort of African-American HIV-infected and at-risk HIV-seronegative participants followed between 1988 and 2004

BACKGROUND

HIV-infected African-Americans are at increased risk of end-stage renal disease requiring renal replacement therapy (RRT).

OBJECTIVES

To compare the incidence of RRT in HIV-infected and HIV-seronegative African-Americans and describe temporal trends in RRT and chronic kidney disease (CKD) in HIV infection.

DESIGN

Cohort study in Baltimore including 4509 HIV-infected and 1746 HIV-seronegative African-Americans.

METHODS

Incident RRT was defined by matching participant identifiers with the US Renal Data System; CKD was defined as an estimated glomerular filtration rate < 60 ml/min per 1.73m for >/= 3 months. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were calculated by indirect adjustment. Risk factors for RRT were assessed by person-time methods and Poisson regression.

RESULTS

RRT was initiated in 24 HIV-seronegative subjects over 13 415 person-years of follow-up (SIR, 2.3; 95% CI, 1.5-3.4), in 51 HIV-infected participants without AIDS over 10 780 person-years (SIR, 6.9; 95% CI, 5.1-9.0), and in 125 participants with AIDS over 9833 person-years. SIR, 16.1; 95% CI, 13.4-19.2). In HIV-infected African-Americans, RRT incidences were 5.8 and 9.7/1000 person-years in the pre-HAART and HAART eras, respectively (adjusted rate ratio 1.2; 95% CI, 0.8-1.9). In supplementary analyses, CKD incidence declined significantly in the HAART era compared with pre-HAART, but the CKD period prevalence increased.

CONCLUSIONS

Nearly 1% of HIV-infected African-Americans initiated RRT annually, a rate that was similar in the HAART and pre-HAART eras. While new cases of CKD decreased, the prevalence of CKD increased in the HAART era, primarily because survival in those with HIV-associated CKD has improved.

Kidney disease in the HIV-infected patient

As survival has improved in the highly active antiretroviral therapy (HAART) era, the prevalence of kidney disease is increasing in the aging HIV-infected population. Since HIV-specific kidney disease, particularly human immunodeficiency virus-associated nephropathy (HIVAN), incidence has remained stable if not declining in the HAART era, the rising rates reflect to a great extent increases in kidney disease seen in the general population due to hypertension and diabetes. In addition, HIV-infected patients are exposed to toxicities of antiretrovirals and other drugs. There is also a disproportionate prevalence of HIV in black Americans, who have a higher risk of kidney disease and the associated risk factors. Because of the high rates of kidney disease, screening for kidney dysfunction is recommended at the time of HIV diagnosis. Because kidney disease is usually asymptomatic, effective screening will include assessment of risk factors and markers of kidney disease, specifically estimations of glomerular filtration rate using serum creatinine and quantification of urine protein. Upon identification of renal dysfunction, the differential diagnosis may be broad, including etiologies common in the general population as well as HIV-specific causes. Although clinical diagnoses can be made, a kidney biopsy is often necessary. Regardless of the cause of kidney disease, early identification, accurate diagnosis and consequent appropriate management are likely to result in improved outcomes. Success in confronting this growing problem can only be achieved with better understanding of kidney diseases affecting the HIV population.

Angiotensin II provokes podocyte injury in murine model of HIV-associated nephropathy

Conditional transgenic mice that express one of the human immunodeficiency virus (HIV)-1 accessory genes, vpr, selectively in podocytes using a podocin promoter and a tetracycline-inducible system develop renal injuries similar to those of patients with HIV-associated nephropathy (HIVAN). We have shown that a heminephrectomy accelerates podocyte injury, which is alleviated by angiotensin II (ANG II) type 1 receptor blocker (ARB). The current study further explores the role of ANG II in the genesis of HIVAN in this murine model. With ANG II infusion, heavy proteinuria was observed at 1 wk after the initiation of doxycycline administration to induce vpr expression in podocytes. Severe morphological and phenotypical changes in the podocytes were observed at 2 wk, together with extensive glomerulosclerosis. Norepinephrine infusion, instead of ANG II, increased the systemic blood pressure to the same level as that achieved using ANG II. However, albuminuria and glomerular injury were modest in norepinephrine-infused mice. Treatment with an ARB, olmesartan, almost completely inhibited glomerular injury. In contrast, lowering the blood pressure with a vasodilator, hydralazine, partially decreased albuminuria but did not produce any histological changes. ANG II infusion alone without doxycycline resulted in a lower level of albuminuria and minimal histological changes. These data demonstrate that excessive ANG II accelerates vpr-induced podocyte injury in a mouse model of HIVAN.

Chronic kidney disease in HIV infection: an urban epidemic

Kidney disease is an important complication of HIV, particularly in minority populations. We describe the burden of chronic kidney disease among 1239 adults followed at an urban AIDS center, with an estimated prevalence of 15.5% (n = 192). Independent predictors of kidney disease included older age, black race, hepatitis C virus exposure, and lower CD4 cell count. These data suggest that chronic kidney disease remains a common complication of HIV infection in the era of antiretroviral therapy.

HIV-1 and HIV-Associated Nephropathy 25 Years Later

Twenty-five years after the first published description of AIDS, HIV-associated nephropathy (HIVAN) remains an important cause of kidney disease in HIV-infected patients. The pathogenesis of HIVAN involves direct HIV infection of the kidney, with both viral and host genetic factors playing an important role. The widespread use of antiretroviral therapy has influenced the epidemiology of HIV-related kidney disease, and the nephrology community should support efforts to improve access to therapy and limit HIV transmission in susceptible minority populations. This article reviews the history of HIV and HIVAN, focusing on advances in the understanding of pathogenesis, epidemiology, and treatment.