HIV-associated nephropathy in the era of antiretroviral therapy

Crack cocaine use frequency is associated with HIV disease severity independent of antiretroviral therapy exposure: a prospective cohort study

We sought to evaluate the effect of crack cocaine use frequency on HIV disease severity among HIV-positive people who use unregulated drugs (PWUD). We analyzed data from the ACCESS study, an open prospective cohort of HIV-positive PWUD including comprehensive HIV clinical monitoring in a setting with no-cost healthcare. Multivariable generalized linear mixed-effects models were used to estimate the independent effect of time-updated crack cocaine use frequency on HIV disease severity, adjusting for ART exposure and relevant confounders. In multivariable adjusted models, daily or greater frequency of crack cocaine use was significantly associated with higher VACS Index scores (β = 0.8, 95% confidence interval: 0.1, 1.5) as compared to none. Our finding suggests that daily or greater frequency of crack cocaine use exacerbates HIV disease severity independent of ART exposure. The observed effect may reflect an underlying biological mechanism or other factors linked with crack cocaine use; further investigation is warranted.

Prevalence of Renal Disease in Human Immunodeficiency Virus-Infected Children in Calabar, Nigeria

Renal disease is increasingly being reported in human immunodeficiency virus (HIV)-infected children with or without antiretroviral drugs. This study was aimed at determining the prevalence of renal disease in HIV-infected children with or without treatment in Calabar, Nigeria. A descriptive cross-sectional study of 146 consecutive HIV-infected children seen at the pediatric HIV clinic of General Hospital Calabar and University of Calabar Teaching Hospital, aged six weeks to 15 years, was carried out from February 1 to September 30, 2015. Demographic and clinical data were obtained by interviewing parents and from medical records of each subject. Clinical examination, anthropometry (weight and height), and blood pressure were done on each child. Each child's urine was tested for persistent proteinuria using combi-10-urinalysis strips. All negative urine samples had urine albumin and urine creatinine determined using immunoturbidimetric assay and Jaffe kinetic reaction, respectively; hence, the urine albumin and urine creatinine ratio was calculated. The serum creatinine of each subject was estimated and used to calculate estimated glomerular filtration rate (eGFR) using Schwartz formula. Renal disease was defined by persistent proteinuria >+1 on dipstick or urine protein-creatinine ratio >0.2, decreased eGFR <60 mL/min/1.73 m², and presence of microalbuminuria (urine albumin/creatinine ratio >30-300 mg/g). Data were analyzed using IBM SSPS Statistics version 20.0, and P ≤0.05 was statistically significant. A total of 146 children were recruited. Eighty-five (58.2%) were male and 61 (41.8%) were female giving a male:female ratio of 1:0.7. Fifty-three (36.3%) had renal disease, 48 (32.9%) had microalbuminuria, and five (3.4%) had persistent proteinuria. There was no significant association between renal disease and severe HIV disease (P >0.05), highly active antiretroviral therapy treatment (P >0.05), and duration of treatment (P >0.05). Renal disease is common in HIV-infected children with or without medication. Hence, they should be screened for renal disease at diagnosis and periodically.

Continuous renal replacement therapy in patients with HIV/AIDS

Background

Acute kidney injury (AKI) is a common complication among human immunodeficiency virus (HIV)-infected patients resulting in increased morbidity and mortality. Continuous renal replacement therapy (CRRT) is a useful method and instrument in critically ill patients with fluid overload and metabolic disarray, especially in those who are unable to tolerate the intermittent hemodialysis. However, the epidemiology, influence factors of CRRT and mortality in patients with HIV/AIDS are still unclear in China. This study aims to study the HIV-infected patients admitted in Intensive Care Unit (ICU) and explore the influence factors correlated with CRRT and their prognosis.

Methods

We performed a retrospective case-control study in the ICU of the Beijing Ditan Hospital Capital Medical University. From June 1, 2005 to May 31, 2017, 225 cases were enrolled in this clinical study.

Results

122 (54.2%) patients were diagnosed with AKI during their stay in ICU, the number and percentage of AKI stage 1, 2 and 3 were 38 (31.1%), 21(17.2%) and 63(51.7%), respectively. 26.2% of AKI patients received CRRT during the stay of ICU. 56.25% CRRT patients died in ICU. The 28-day mortality was 62.5%, and the 90-day mortality was 75%. By univariate logistics analysis, it showed that higher likelihood of diagnosis for respiratory failure (OR = 7.333,95% CI 1.467–36.664, p = 0.015), higher likelihood of diagnosis for septic shock (OR = 1.005,95% CI 1.001–1.01, p = 0.018), and higher likelihood to use vasoactive agents (OR = 10.667,95% CI 1.743–65.271, p = 0.001), longer mechanical ventilation duration (OR = 1.011,95% CI 1.002–1.019, p = 0.011), higher likelihood for diagnosis for PCP (OR = 7.50,95% CI 1.288–43.687, p = 0.025), higher SOFA score at ICU admission (OR = 1.183,95% CI 1.012–1.383, p = 0.035), longer duration of CRRT (OR = 1.014,95% CI 1.001–1.028, p = 0.034) contributed to a higher mortality at ICU. The Cox Analysis for the cumulative survival of AKI 3 patients between the CRRT and non-CRRT groups shows no significant differences (p = 0.595).

Conclusions

There is a high incidence of AKI in HIV-infected patients admitted in our ICU. Patients with severe AKI were more prone to be admitted for CRRT and have a consequent poor prognosis.

Protective association between JC polyoma viruria and kidney disease

PURPOSE OF REVIEW

The presence of viruses in urine (urine virome) typically reflects infection in the kidneys and urinary tract. The urinary virome is associated with HIV-associated nephropathy and chronic glomerulosclerosis. There are many associations of this microbiome with human diseases that remain to be described. This manuscript reviews emerging data on relationships between kidney disease and urinary tract infection/colonization with JC polyomavirus (JCPyV).

RECENT FINDINGS

Approximately 30% of the adult population sheds JCPyV in the urine. Further, urinary tract infection with one polyomavirus strain appears to inhibit secondary infections. The presence of urinary JCPyV and BK polyomavirus (BKPyV) replication were measured with polymerase chain reaction in African Americans to assess relationships with apolipoprotein L1 gene (APOL1)-associated nephropathy. Urinary JCPyV was associated with paradoxically lower rates of nephropathy in those with APOL1 high-risk genotypes. Subsequent studies revealed African Americans with JCPyV viruria had lower rates of nondiabetic nephropathy independent from APOL1.

SUMMARY

Urinary tract JCPyV replication is common and associates with lower rates of nephropathy. This relationship is observed in diverse settings. Results support a host immune system that fails to eradicate nonnephropathic viruses and is also less likely to manifest renal parenchymal inflammation resulting in glomerulosclerosis.

Are T cells the only HIV-1 reservoir?

Current antiretroviral therapies have improved the duration and quality of life of people living with HIV-1. However, viral reservoirs impede complete eradication of the virus. Although there are many strategies to eliminate infectious virus, the most actively pursued are latency reversing agents in conjunction with immune modulation. This strategy, known as “shock and kill”, has been tested primarily against the most widely recognized HIV-1 latent reservoir found in resting memory CD4+ T cells. This is in part because of the dearth of conclusive evidence about the existence of non-T cell reservoirs. Studies of non-T cell reservoirs have been difficult to interpret because of technical and biological issues that have hampered a better understanding. This review considers the current knowledge of non-T cell reservoirs, the challenges encountered in a better understanding of these populations, and their implications for HIV-1 cure research.

Continuous Ambulatory Peritoneal Dialysis in Patients with HIV and End-Stage Renal Failure

♦ BACKGROUND: This study aimed to evaluate the differences in continuous ambulatory peritoneal dialysis (CAPD)-related outcomes according to human immunodeficiency virus (HIV) status of end-stage renal failure patients. ♦ METHODS: This prospective cohort study included 70 HIV-negative and 70 HIV-positive consecutive patients with renal failure who underwent dialysis with newly inserted Tenckhoff catheters between September 2012 and February 2015. Patients were followed up monthly at a central renal clinic for 1 year or until the primary endpoints of technique failure or death. ♦ RESULTS: Technique failure rates were similar (HIV-negative: 0.270 episodes/person-year; HIV-positive: 0.298 episodes/person-year; hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.51 - 2.32; p = 0.822). However, there were fewer HIV-positive patients with complete 1-year follow-up with a patent catheter (42.9% vs 58.6% in the HIV-negative cohort; p = 0.063) owing to their higher all-cause mortality rate (0.55 vs 0.25 deaths/person-year, respectively; HR, 2.11; CI, 1.07 - 4.14; p = 0.031). Cluster of differentiation 4 count (CD4) < 200/μL (HR, 5.39; CI, 2.20 - 13.21; p < 0.001) and unsuppressed viral load (HR, 3.63; CI 1.72 - 7.67; p = 0.001) were associated with increased mortality hazards. Rates of first peritonitis were 0.616 (HIV-negative) and 1.668 (HIV-positive) episodes/person-year (HR, 2.38; CI, 1.46 - 3.89; p = 0.001). All-cause admission rates were 1.52 (HIV-negative) and 2.97 (HIV-positive) hospital admissions/person-year (HR, 1.66; CI, 1.12 - 2.48; p = 0.013). ♦ CONCLUSION: Although HIV-seropositive status of patients on CAPD did not adversely influence technique failure rates or patency at 1 year, uncontrolled HIV infection may be associated with increased relative risk of mortality and morbidity.

The kidney as a reservoir for HIV-1 after renal transplantation

Since the recent publication of data showing favorable outcomes for patients with HIV-1 and ESRD, kidney transplantation has become a therapeutic option in this population. However, reports have documented unexplained reduced allograft survival in these patients. We hypothesized that the unrecognized infection of the transplanted kidney by HIV-1 can compromise long-term allograft function. Using electron microscopy and molecular biology, we examined protocol renal transplant biopsies from 19 recipients with HIV-1 who did not have detectable levels of plasma HIV-1 RNA at transplantation. We found that HIV-1 infected the kidney allograft in 68% of these patients. Notably, HIV-1 infection was detected in either podocytes predominately (38% of recipients) or tubular cells only (62% of recipients). Podocyte infection associated with podocyte apoptosis and loss of differentiation markers as well as a faster decline in allograft function compared with tubular cell infection. In allografts with tubular cell infection, epithelial cells of the proximal convoluted tubules frequently contained abnormal mitochondria, and both patients who developed features of subclinical acute cellular rejection had allografts with tubular cell infection. Finally, we provide a novel noninvasive test for determining HIV-1 infection of the kidney allograft by measuring HIV-1 DNA and RNA levels in patients' urine. In conclusion, HIV-1 can infect kidney allografts after transplantation despite undetectable viremia, and this infection might influence graft outcome.

Kidney disease in children and adolescents with perinatal HIV-1 infection

Introduction

Involvement of the kidney in children and adolescents with perinatal (HIV-1) infection can occur at any stage during the child's life with diverse diagnoses, ranging from acute kidney injury, childhood urinary tract infections (UTIs), electrolyte imbalances and drug-induced nephrotoxicity, to diseases of the glomerulus. The latter include various immune-mediated chronic kidney diseases (CKD) and HIV-associated nephropathy (HIVAN).

Discussion

The introduction of highly active anti-retroviral therapy (HAART) has dramatically reduced the incidence of HIVAN, once the commonest form of CKD in children of African descent living with HIV, and also altered its prognosis from eventual progression to end-stage kidney disease to one that is compatible with long-term survival. The impact of HAART on the outcome of other forms of kidney diseases seen in this population has not been as impressive. Increasingly important is nephrotoxicity secondary to the prolonged use of anti-retroviral agents, and the occurrence of co-morbid kidney disease unrelated to HIV infection or its treatment. Improved understanding of the molecular pathogenesis and genetics of kidney diseases associated with HIV will result in better screening, prevention and treatment efforts, as HIV specialists and nephrologists coordinate clinical care of these patients. Both haemodialysis (HD) and peritoneal dialysis (PD) are effective as renal replacement therapy in HIV-infected patients with end-stage kidney disease, with PD being preferred in resource-limited settings. Kidney transplantation, once contraindicated in this population, has now become the most effective renal replacement therapy, provided rigorous criteria are met. Given the attendant morbidity and mortality in HIV-infected children and adolescents with kidney disease, routine screening for kidney disease is recommended where resources permit.

Conclusions

This review focuses on the pathogenesis and genetics, clinical presentation and management of kidney disease in children and adolescents with perinatal HIV-1 infection.

Willingness to pursue live-donor kidney transplantation among waitlisted patients infected with human immunodeficiency virus (HIV): a preliminary investigation

We show that HIV-infected waitlisted patients (n=33) had significantly lower knowledge (P<0.001), more concerns (P=0.01), and lower willingness to pursue live-donor kidney transplantation (LDKT; P=0.02) than matched noninfected patients. The majority (78%) of patients felt that their HIV status reduced their chance of LDKT. Although limited to a single center and a small sample, our data suggest that HIV-infected patients who are waitlisted for kidney transplantation may need more education about the potential benefits of LDKT and may benefit from patient-centered decision support to facilitate a risk-benefit assessment consistent with their preferences and values.

Renoprotective effect of combined inhibition of angiotensin-converting enzyme and histone deacetylase

The Connectivity Map database contains microarray signatures of gene expression derived from approximately 6000 experiments that examined the effects of approximately 1300 single drugs on several human cancer cell lines. We used these data to prioritize pairs of drugs expected to reverse the changes in gene expression observed in the kidneys of a mouse model of HIV-associated nephropathy (Tg26 mice). We predicted that the combination of an angiotensin-converting enzyme (ACE) inhibitor and a histone deacetylase inhibitor would maximally reverse the disease-associated expression of genes in the kidneys of these mice. Testing the combination of these inhibitors in Tg26 mice revealed an additive renoprotective effect, as suggested by reduction of proteinuria, improvement of renal function, and attenuation of kidney injury. Furthermore, we observed the predicted treatment-associated changes in the expression of selected genes and pathway components. In summary, these data suggest that the combination of an ACE inhibitor and a histone deacetylase inhibitor could have therapeutic potential for various kidney diseases. In addition, this study provides proof-of-concept that drug-induced expression signatures have potential use in predicting the effects of combination drug therapy.

A systems approach identifies HIPK2 as a key regulator of kidney fibrosis

Kidney fibrosis is a common process that leads to the progression of various types of kidney disease. We used an integrated computational and experimental systems biology approach to identify protein kinases that regulate gene expression changes in the kidneys of human immunodeficiency virus (HIV) transgenic mice (Tg26 mice), which have both tubulointerstitial fibrosis and glomerulosclerosis. We identified homeo-domain interacting protein kinase 2 (HIPK2) as a key regulator of kidney fibrosis. HIPK2 was upregulated in the kidneys of Tg26 mice and in those of patients with various kidney diseases. HIV infection increased the protein concentrations of HIPK2 by promoting oxidative stress, which inhibited the seven in absentia homolog 1 (SIAH1)-mediated proteasomal degradation of HIPK2. HIPK2 induced apoptosis and the expression of epithelial-to-mesenchymal transition markers in kidney epithelial cells by activating the p53, transforming growth factor β (TGF-β)-SMAD family member 3 (Smad3) and Wnt-Notch pathways. Knockout of HIPK2 improved renal function and attenuated proteinuria and kidney fibrosis in Tg26 mice, as well as in other murine models of kidney fibrosis. We therefore conclude that HIPK2 is a potential target for anti-fibrosis therapy.

Roflumilast enhances the renal protective effects of retinoids in an HIV-1 transgenic mouse model of rapidly progressive renal failure

Retinoic acid decreases proteinuria and glomerulosclerosis in several animal models of kidney disease by protecting podocytes from injury. Our recent in vitro studies suggest that all-trans retinoic acid induces podocyte differentiation by activating the retinoic acid receptor-α (RARα)/cAMP/PKA/CREB pathway. When used in combination with all-trans retinoic acid, an inhibitor of phosphodiesterase 4 further enhanced podocyte differentiation by increasing intracellular cAMP. Additionally, we found that Am580, a specific RARα agonist, has similar renal protective effects as all-trans retinoic acid in a rederived colony of HIV-1 transgenic mice with rapidly progressive renal failure (HIV-Tg) that mimics human HIV-associated nephropathy. Treatment with either the inhibitor of phoshodiesterase 4, roflumilast, or Am580 significantly reduced proteinuria, attenuated kidney injury, and improved podocyte differentiation in these HIV-Tg mice. Additional renal protective effects were found when roflumilast was combined with Am580. Consistent with the in vitro data, glomeruli from HIV-Tg mice treated with both Am580 and roflumilast had more active phosphorylated CREB than with either agent alone. Thus, phosphodiesterase 4 inhibitors could be used in combination with RARα agonists to provide additional renal protection.

Immune reconstitution renal-limited sarcoidosis presenting as acute kidney injury

An HIV-infected asymptomatic woman developed acute kidney injury six weeks after initiation of combination antiretroviral therapy (cART). A renal biopsy revealed both renal-limited sarcoidosis and HIV nephropathy. The acute renal injury reversed with glucocorticoid therapy.

Novel retinoic acid receptor alpha agonists for treatment of kidney disease

Development of pharmacologic agents that protect podocytes from injury is a critical strategy for the treatment of kidney glomerular diseases. Retinoic acid reduces proteinuria and glomerulosclerosis in multiple animal models of kidney diseases. However, clinical studies are limited because of significant side effects of retinoic acid. Animal studies suggest that all trans retinoic acid (ATRA) attenuates proteinuria by protecting podocytes from injury. The physiological actions of ATRA are mediated by binding to all three isoforms of the nuclear retinoic acid receptors (RARs): RARα, RARβ, and RARγ. We have previously shown that ATRA exerts its renal protective effects mainly through the agonism of RARα. Here, we designed and synthesized a novel boron-containing derivative of the RARα-specific agonist Am580. This new derivative, BD4, binds to RARα receptor specifically and is predicted to have less toxicity based on its structure. We confirmed experimentally that BD4 binds to RARα with a higher affinity and exhibits less cellular toxicity than Am580 and ATRA. BD4 induces the expression of podocyte differentiation markers (synaptopodin, nephrin, and WT-1) in cultured podocytes. Finally, we confirmed that BD4 reduces proteinuria and improves kidney injury in HIV-1 transgenic mice, a model for HIV-associated nephropathy (HIVAN). Mice treated with BD4 did not develop any obvious toxicity or side effect. Our data suggest that BD4 is a novel RARα agonist, which could be used as a potential therapy for patients with kidney disease such as HIVAN.

APOL1 variants increase risk for FSGS and HIVAN but not IgA nephropathy

A chromosome 22q13 locus strongly associates with increased risk for idiopathic focal segmental glomerulosclerosis (FSGS), HIV-1-associated nephropathy (HIVAN), and hypertensive ESRD among individuals of African descent. Although initial studies implicated MYH9, more recent analyses localized the strongest association within the neighboring APOL1 gene. In this replication study, we examined the six top-most associated variants in APOL1 and MYH9 in an independent cohort of African Americans with various nephropathies (44 with FSGS, 21 with HIVAN, 32 with IgA nephropathy, and 74 healthy controls). All six variants associated with FSGS and HIVAN (additive ORs, 1.8 to 3.0; P values 3 × 10(-2) to 5 × 10(-5)) but not with IgA nephropathy. In conditional and haplotype analyses, two APOL1 haplotypes accounted for virtually all of the association with FSGS and HIVAN on chromosome 22q13 (haplotype P value = 5.6 × 10(-8)). To assess the role of MYH9 deficiency in nephropathy, we crossbred Myh9-haploinsufficient mice (Myh9(+/-)) with HIV-1 transgenic mice. Myh9(+/-) mice were healthy and did not demonstrate overt proteinuria or nephropathy, irrespective of the presence of the HIV-1 transgene. These data further support the strong association of genetic variants in APOL1 with susceptibility to FSGS and HIVAN among African Americans.

[Risk factors related to renal disorders in HIV-1 infected patients]

INTRODUCTION

Renal disease has emerged as one of the primary comorbid conditions affecting HIV-infected patients, mainly because antiretroviral therapy has improved survival. This study aimed to detect risk factors possibly associated with altered renal function in HIV-infected patients.

METHODS

A cross-sectional study was conducted involving 254 HIV-infected patients attending an outpatient clinic at Santa Casa de Vitoria< They were interviewed and blood samples were collected for CD4 cell counts, HIV-1 viral load, glucose, lipids and creatinine measurements. Urine protein was evaluated in the first voiding urine sample. Glomerular filtration was estimated by simplified modified diet in renal disease (MDRD) and Cockcroft-Gault formulas.

RESULTS

One hundred and three (40.6%) patients presented some urinary abnormality, and proteinuria was the most common finding (46; 18.1% patients). Twenty-five (9.8%) patients showed estimated glomerular filtration below 60 ml/min/1.73 m² by MDRD. Multivariate logistic regression showed that low glomerular filtration was positively correlated with black race [OR 9.6 (IC95% 1.28-23.80)], arterial hypertension [OR 3.3 (IC95% 1.28-23.81)], age over fifty-one years-old [OR 3.3 (IC95%1.11-9.90)], proteinuria [OR 5.2 {IC95% 1.67-16.25}]; hematuria [OR 3.2 (1.12-9.29)] and negatively correlated with patients using zidovudine [OR 0.2 (0.04-0.78)].

CONCLUSIONS

Traditional risk factors for renal disease, such as black race, arterial hypertension and advancing age were correlated with low estimated glomerular filtration in the present patient sample.

Increased prevalence of albuminuria in HIV-infected adults with diabetes

Objective

HIV and type 2 diabetes are known risk factors for albuminuria, but no previous reports have characterized albuminuria in HIV-infected patients with diabetes.

Research Design and Methods

We performed a cross-sectional study including 73 HIV-infected adults with type 2 diabetes, 82 HIV-infected non-diabetics, and 61 diabetic control subjects without HIV. Serum creatinine >1.5 mg/dL was exclusionary. Albuminuria was defined as urinary albumin/creatinine ratio >30 mg/g.

Results

The prevalence of albuminuria was significantly increased among HIV-infected diabetics (34% vs. 13% of HIV non-diabetic vs. 16% diabetic control, p = 0.005). HIV status and diabetes remained significant predictors of albuminuria after adjusting for age, race, BMI, and blood pressure. Albumin/creatinine ratio correlated significantly with HIV viral load (r = 0.28, p = 0.0005) and HIV-infected subjects with albuminuria had significantly greater cumulative exposure to abacavir (p = 0.01). In an adjusted multivariate regression analysis of HIV-infected subjects, the diagnosis of diabetes (p = 0.003), higher HIV viral load (p = 0.03) and cumulative exposure to abacavir (p = 0.0009) were significant independent predictors of albuminuria.

Conclusions

HIV and diabetes appear to have additive effects on albuminuria which is also independently associated with increased exposure to abacavir and HIV viral load. Future research on the persistence, progression and management of albuminuria in this unique at-risk population is needed.

Longitudinal assessment of metabolic abnormalities in adolescents and young adults with HIV-infection acquired perinatally or in early childhood

Metabolic complications of HIV pose challenges for health maintenance among young adults who acquired HIV in early childhood. Between July 2004 and July 2009, we evaluated 47 HIV-infected subjects who acquired HIV in early life. Participants completed glucose tolerance testing; insulin, lipid, urine albumin, and creatinine determinations; and dual-energy x-ray absorptiometry scans. Longitudinal data were available for 39 subjects; duration of follow-up was 26.4 ± 16.8 months. At baseline, participants were 17.1 ± 3.9 years old; and duration of antiretroviral therapy was 12.7 ± 3.4 years. CD4 count was 658 ± 374 cells per cubic millimeter, and 55% had undetectable viral load. Impaired glucose tolerance was present in 15%; 33% had insulin resistance (homeostasis model assessment of insulin resistance >4.0). Furthermore, 52% had triglycerides of at least 150 mg/dL, 36% had high-density lipoprotein cholesterol less than 40 mg/dL, 18% had low-density lipoprotein cholesterol of at least 130 mg/dL, and 25% had total cholesterol of at least 200 mg/dL. Microalbuminuria was present in 15% of participants and was inversely correlated with CD4% (P = .001). During follow-up, more than one third remained insulin resistant; lipid parameters tended to improve. There were significant increases in body mass index (P = .0002), percentage leg fat (P = .008), and percentage trunk fat (P = .002). Impaired glucose tolerance, insulin resistance, dyslipidemia, and microalbuminuria are common among young adults with HIV. Long-term exposure to therapy may translate into substantial persistent metabolic risk.

Role of the retinoic acid receptor-α in HIV-associated nephropathy

All-trans retinoic acid protects against the development of HIV-associated nephropathy (HIVAN) in HIV-1 transgenic mice (Tg26). In vitro, all-trans retinoic acid inhibits HIV-induced podocyte proliferation and restores podocyte differentiation markers by activating its receptor-α (RARα). Here, we report that Am580, a water-soluble RARα-specific agonist, attenuated proteinuria, glomerosclerosis, and podocyte proliferation, and restored podocyte differentiation markers in kidneys of Tg26 mice. Furthermore, RARα-/- Tg26 mice developed more severe kidney and podocyte injury than did RARα+/- Tg26 mice. Am580 failed to ameliorate kidney injury in RARα-/- Tg26 mice, confirming our hypothesis that Am580 acts through RARα. Although the expression of RARα-target genes was suppressed in the kidneys of Tg26 mice and of patients with HIVAN, the expression of RARα in the kidney was not different between patients with HIVAN and minimal change disease. However, the tissue levels of retinoic acid were reduced in the kidney cortex and isolated glomeruli of Tg26 mice. Consistent with this, the expression of two key enzymes in the retinoic acid synthetic pathway, retinol dehydrogenase type 1 and 9, and the overall enzymatic activity for retinoic acid synthesis were significantly reduced in the glomeruli of Tg26 mice. Thus, a defect in the endogenous synthesis of retinoic acid contributes to loss of the protection by retinoic acid in HIVAN. Hence, RARα agonists may be potential agents for the treatment of HIVAN.

HIV and the body: a review of multidisciplinary management

The increase in the life expectancy achieved following the introduction of more effective antiretroviral therapy (ART) in recent years now means that the HIV-infected population are for the first time being exposed to the age-related diseases that affect the general population. Nevertheless, the prevalence of these diseases (which include cardiovascular disease, dyslipidaemia, glucose intolerance and diabetes) is higher, and their onset earlier in the HIV population, probably due to the complex interplay between HIV infection, coinfection with hepatitis B and C, and ART. As a result, HIV physicians are now required to adopt a new approach to the management of HIV, which involves screening and regular monitoring of all HIV-infected individuals for the presence of comorbidities and prompt referral to other clinical specialties when required. If this challenge to patient management is to be overcome, it is clear that educating physicians in the diagnosis and treatment of age-associated comorbidities is essential, either through ongoing programmes such as the HIV and the Body initiative, an overarching independent medical education programme established in 2007 and overseen by an independent Steering Committee, organized and funded by Gilead, and/or through internal training. To assist in this process, this article provides an overview of common comorbidities affecting HIV-infected persons and provides practical guidance on their management.

The molecular pathogenesis of HIV-1 associated nephropathy: recent advances

HIV-1-associated nephropathy (HIVAN) is a major complication of HIV-1 infection, frequently resulting in kidney failure. HIVAN arises due to HIV-1-induced dysregulation of podocytes, the glomerular epithelial cells that establish and maintain the kidney filtration barrier. Host genetic factors are important for the development of HIVAN. The risk of HIVAN is greatest in populations of African ancestry, and is attributable to a genetic variation at the APOL1 locus on chromosome 22. Mouse models of HIVAN enable delineation of dysregulated pathways underlying disease. Identification of HIVAN susceptibility loci in a mouse model, combined with expression quantitative trait locus mapping, has demonstrated that murine HIVAN loci transregulate podocyte gene expression. HIV-1 induces perturbations in podocyte expression response, suggesting that HIV-1 potentially interferes with compensatory pathways that normally restore cellular homeostasis in the face of genetic mutations. These findings present a framework for identification of podocyte transregulators and reconstruction of the molecular networks connecting susceptibility genes to the development of nephropathy.

Prevalence of chronic renal failure stage 3 or more in HIV-infected patients in Antwerp: an observational study

The introduction of Highly Active Antiretroviral Therapy has transformed HIV-infection from an inevitably lethal disease to a chronic condition with a life expectancy comparable to that of people with diabetes mellitus. In recent years it has become evident that people living with HIV/AIDS have an increased risk of developing cardiovascular disease and it is expected that the prevalence of chronic kidney disease will rise accordingly. To investigate the prevalence of chronic kidney disease in patients with HIV, we conducted a retrospective observational analysis using the clinical database of a large centre (Institute of Tropical Medicine) in the urban area of Antwerp, Belgium. The prevalence of chronic kidney disease among HIV infected subjects was found to be 3.0%. The development of chronic kidney disease was associated with age above 50 years, lower CD4 cell counts and Caucasian origin. Screening for chronic renal disorders and prevention of evolution toward chronic renal failure is a crucial challenge in the management of people living with HIV/AIDS.

Acute kidney injury in AIDS: frequency, RIFLE classification and outcome

The objective of the present study was to evaluate the characteristics of acute kidney injury (AKI) in AIDS patients and the value of RIFLE classification for predicting outcome. The study was conducted on AIDS patients admitted to an infectious diseases hospital inBrazil. The patients with AKI were classified according to the RIFLE classification: R (risk), I (injury), F (failure), L (loss), and E (end-stage renal disease). Univariate and multivariate analyses were used to evaluate the factors associated with AKI. A total of 532 patients with a mean age of 35 ± 8.5 years were included in this study. AKI was observed in 37% of the cases. Patients were classified as "R" (18%), "I" (7.7%) and "F" (11%). Independent risk factors for AKI were thrombocytopenia (OR = 2.9, 95%CI = 1.5-5.6, P < 0.001) and elevation of aspartate aminotransferase (AST) (OR = 3.5, 95%CI = 1.8-6.6, P < 0.001). General mortality was 25.7% and was higher among patients with AKI (40.2 vs17%, P < 0.001). AKI was associated with death and mortality increased according to RIFLE classification - "R" (OR 2.4), "I" (OR 3.0) and "F" (OR 5.1), P < 0.001. AKI is a frequent complication in AIDS patients, which is associated with increased mortality. RIFLE classification is an important indicator of poor outcome for AIDS patients.

Renal insufficiency has no effect on the pharmacokinetics of vicriviroc in a ritonavir-containing regimen

BACKGROUND AND OBJECTIVE

Vicriviroc is a small-molecule CCR5 antagonist currently in development for the treatment of HIV in patients on a regimen containing a ritonavir-boosted protease inhibitor. As renal disease and renal dysfunction are prevalent in the HIV-infected population, patients with varying degrees of renal insufficiency may receive vicriviroc, which is metabolized by cytochrome P450 (CYP) 3A4. The present study therefore examined the impact of renal insufficiency on the pharmacokinetics and safety of vicriviroc alone and in the presence of ritonavir, a strong CYP3A4 inhibitor.

SUBJECTS AND METHODS

This study was an open-label, randomized, two-treatment crossover trial conducted in HIV-negative subjects with haemodialysis-dependent end-stage renal disease (ESRD) and healthy subjects with normal renal function matched by age, height, bodyweight and sex. Subjects received a single dose of vicriviroc 75 mg alone in one period, and in another period they received a single dose of vicriviroc 15 mg after 4 days of ritonavir 100 mg once daily. Ritonavir treatment was then continued for an additional 13 days. The two trial periods were separated by an interval of at least 3 weeks. The primary endpoints were the log-transformed area under the plasma concentration-time curve (AUC) and the maximum plasma concentration (C(max)), and the 90% confidence intervals (CIs) of the mean differences between subjects with ESRD and matched healthy subjects. The protocol provided the option of dose modification and further study if the vicriviroc C(max) and AUC values were at least twice as high in subjects with ESRD compared with healthy subjects, or if warranted by other safety and tolerability observations.

RESULTS

Twelve subjects (six with ESRD, six healthy) completed the study. When vicriviroc was administered alone, the mean vicriviroc C(max) and AUC ratio estimates (90% CI) for subjects with ESRD versus healthy subjects were 74% (53, 103) and 84% (49, 145), respectively. When ritonavir was added to the regimen, the ratio estimates (90% CI) were 81% (59, 111) and 134% (105, 171), respectively. Ritonavir plasma concentrations were substantially higher in subjects with ESRD than in healthy subjects. Treatment-emergent adverse events considered possibly or probably related to treatment occurred only during the ritonavir period of the study and in one healthy subject and two subjects with ESRD; all were of mild or moderate severity.

CONCLUSIONS

ESRD had no clinically relevant impact on exposure of vicriviroc when vicriviroc was administered alone or in the presence of ritonavir. In this single-dose study, vicriviroc was well tolerated both by healthy subjects and by those with ESRD. Dose adjustment of vicriviroc is therefore not necessary in renally impaired populations.

Towards a combined prognostic index for survival in HIV infection: the role of 'non-HIV' biomarkers

BACKGROUND

As those with HIV infection live longer, 'non-AIDS' condition associated with immunodeficiency and chronic inflammation are more common. We ask whether 'non-HIV' biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART).

METHODS

Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers (CD4 cell count, HIV RNA and AIDS-defining conditions); 'non-HIV' biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data.

RESULTS

Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and 'non-HIV' markers were associated with each other (P < 0.0001) and discriminated mortality (C statistics 0.68-0.73); when combined, discrimination improved (P < 0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80-0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72-0.74). Results were robust to adjustment for missing data.

CONCLUSIONS

When added to HIV biomarkers, 'non-HIV' biomarkers improve differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research.

CKD in HIV-infected patients other than HIV-associated nephropathy

A spectrum of kidney diseases in HIV-infected patients has been reported both before and after the introduction of highly active antiretroviral therapy (HAART). Kidney syndromes affecting HIV-infected patients include CKD as well as proteinuria, nephrotic syndrome, and acute nephritic syndrome. Thrombotic microangiopathy should be considered in patients with kidney disease and typical clinical characteristics. As the HIV-infected population ages, there is increased concern regarding the incidence of vascular and metabolic disease, leading to an increased burden of CKD. Although HIV-associated nephropathy is still the major cause of nephrotic syndrome in HIV-infected patients, immune complex glomerulonephritis (ICGN) still comprises a substantial proportion of the disease burden, especially in people of European origin. Genetic investigations into the underpinnings of the various histologic expressions of HIV-associated kidney disease hold great promise. The single most important diagnostic test to differentiate various forms of kidney disease in HIV-infected patients is a kidney biopsy. The results of treating kidney disease in HIV-infected patients remain unclear, and properly designed randomized controlled trials of the treatment of ICGN with HAART and other approaches are desperately needed.

HIV-1 Vpr activates the DNA damage response in renal tubule epithelial cells

HIV-associated nephropathy (HIVAN) is a major cause of HIV-related morbidity and mortality. Pathogenesis involves direct infection of the glomerular and tubular epithelial cells leading to characteristic disorder. Recently, we have shown that HIV-1 Vpr causes hypertrophy, hyperploidy, and apoptosis. Here, we report that Vpr activates the DNA damage response resulting in the observed renal phenotype. Renal sections from the HIVAN transgenic mouse model and human biopsies both show an abundant DNA damage response.

Genetic susceptibility to HIV-associated nephropathy

HIV-1-associated nephropathy (HIVAN) is a common complication of HIV-1 infection, and its skewed incidence in certain ethnic groups suggests that there is a genetic basis to HIVAN susceptibility. In their study reported in this issue of the JCI, Papeta and colleagues used a combination of gene expression profiling and linkage analysis to identify three genomic loci that regulate a network of genes expressed by podocytes - cells that are crucial to the filtration of fluid and waste by the kidney (see the related article beginning on page 1178). Surprisingly, two of these loci confer disease susceptibility in a transgenic mouse model of HIVAN. This report confirms the central role of podocytes in the pathogenesis of HIVAN and demonstrates the power of this combination of genomic analysis techniques in elucidating the pathogenesis of glomerular disease.

Susceptibility loci for murine HIV-associated nephropathy encode trans-regulators of podocyte gene expression

Multiple studies have linked podocyte gene variants to diverse sporadic nephropathies, including HIV-1-associated nephropathy (HIVAN). We previously used linkage analysis to identify a major HIVAN susceptibility locus in mouse, HIVAN1. We performed expression quantitative trait locus (eQTL) analysis of podocyte genes in HIV-1 transgenic mice to gain further insight into genetic susceptibility to HIVAN. In 2 independent crosses, we found that transcript levels of the podocyte gene nephrosis 2 homolog (Nphs2), were heritable and controlled by an ancestral cis-eQTL that conferred a 3-fold variation in expression and produced reactive changes in other podocyte genes. In addition, Nphs2 expression was controlled by 2 trans-eQTLs that localized to the nephropathy susceptibility intervals HIVAN1 and HIVAN2. Transregulation of podocyte genes was observed in the absence of HIV-1 or glomerulosclerosis, indicating that nephropathy susceptibility alleles induce latent perturbations in the podocyte expression network. Presence of the HIV-1 transgene interfered with transregulation, demonstrating effects of gene-environment interactions on disease. These data demonstrate that transcript levels of Nphs2 and related podocyte-expressed genes are networked and suggest that the genetic lesions introduced by HIVAN susceptibility alleles perturb this regulatory pathway and transcriptional responses to HIV-1, increasing susceptibility to nephropathy.

Detergent-resistant globotriaosyl ceramide may define verotoxin/glomeruli-restricted hemolytic uremic syndrome pathology

Verotoxin binding to its receptor, globotriaosyl ceramide(Gb(3)) mediates the glomerular pathology of hemolytic uremic syndrome, but Gb(3) is expressed in both tubular and glomerular cells. Gb(3) within detergent-resistant membranes, an index of glycolipid-cholesterol enriched lipid rafts, is required for in vitro cytotoxicity. We found that verotoxin 1 and 2 binding to human adult renal glomeruli is detergent resistant, whereas the strong verotoxin binding to renal tubules is detergent sensitive. Verotoxin binding to pediatric glomeruli was detergent resistant but binding to adult glomeruli was enhanced, remarkably for some samples, by detergent extraction. Detergent-sensitive glomerular components may provide age-related protection against verotoxin glomerular binding. Mouse glomeruli remained verotoxin unreactive after detergent extraction, whereas tubular binding was lost. Cholesterol extraction induced strong verotoxin binding in poorly reactive adult glomeruli, suggesting cholesterol can mask Gb(3) in glomerular lipid rafts. Binding of the human immunodeficiency virus (HIV) adhesin, gp120 (another Gb(3) ligand) was detergent sensitive, tubule-restricted, and inhibited by verotoxin B subunit pretreatment, and may relate to HIV nephropathy. Our study shows that differential membrane Gb(3) organization in glomeruli and tubules provides a basis for the age- and glomerular-restricted pathology of hemolytic uremic syndrome.

Kidney disease in HIV-positive children

Before the era of highly active antiretroviral therapy, more than 40% of human immunodeficiency virus (HIV)-infected children experienced renal complications. In sub-Saharan Africa, approximately 2.1 million children are infected with HIV-1. In the absence of antiretroviral therapy, young African children frequently died of AIDS-related complications before renal diseases could be manifested or diagnosed. As antiretroviral therapy has become more available, and their survival has increased, our experience in treating kidney disease in HIV-infected children has improved. This article discusses relevant clinical and pathologic findings related to kidney disease in HIV-infected children.

Suppression of HIV-1 replication by antiretroviral therapy improves renal function in persons with low CD4 cell counts and chronic kidney disease

OBJECTIVE

To examine the association between changes in glomerular filtration rates (GFR) and antiretroviral therapy (ART)-mediated suppression of plasma HIV-1 viremia.

DESIGN

: Observational, prospective, multicenter cohort study.

INTERVENTION

ART regimens or treatment strategies in HIV-1-infected subjects were implemented through randomized clinical trials; 1776 ambulatory subjects from these trials also enrolled in this cohort study.

METHOD

The association between suppression of viremia and GFR changes from baseline was examined using the abbreviated Modification of Diet and Renal Disease equation in mixed effects linear models.

RESULTS

GFR improvement was associated with ART-mediated suppression of plasma viremia in subjects with both chronic kidney disease stage > or = 2 and low baseline CD4 cell counts (< 200 cells/microl). In this subset, viral suppression (by > 1.0 log10 copies/ml or to < 400 copies/ml) was associated with an average increase in GFR of 9.2 ml/min per 1.73 m(2) from baseline (95% confidence interval, 1.6-16.8; P = 0.02) over a median follow-up of 160 weeks. The magnitude of this association increased in subjects who had greater baseline impairment of renal function, and it did not depend on race or sex.

CONCLUSIONS

Viral suppression was associated with GFR improvements in those with both low CD4 cell counts and impaired baseline renal function, supporting an independent contribution of HIV-1 replication to chronic renal dysfunction in advanced HIV disease. GFR improvement not associated with viral suppression also was observed in subjects with higher CD4 cell counts.