The HIV protease inhibitor darunavir prevents kidney injury via HIV-independent mechanisms.

HIV-associated nephropathy (HIVAN) is a rapidly progressive kidney disease that is caused by HIV infection of renal epithelial cells with subsequent expression of viral genes, including vpr. Antiretroviral therapy ameliorates HIVAN without eradicating HIV from the kidneys and the mechanism by which it protects kidneys is poorly understood. Since HIV protease inhibitors have "off target" cellular effects, we studied whether darunavir, the most commonly prescribed protease inhibitor, protects kidneys from HIV-induced injury via mechanisms independent of HIV protease and viral replication. Renal epithelial cells were transduced with lentiviruses encoding HIV (lacking protease and reverse transcriptase), Vpr, or vector control. Darunavir attenuated HIV and Vpr-induced activation of Stat3, Src, Erk, and cytokines, which are critical for HIVAN pathogenesis. We then studied HIV-transgenic mice, which develop HIVAN in the absence of HIV protease or reverse transcriptase. Mice were treated with darunavir, zidovudine, darunavir + zidovudine, or control. Darunavir and darunavir + zidovudine reduced albuminuria and histologic kidney injury and normalized expression of dysregulated proteins. RNA-seq analyses demonstrated that darunavir suppressed HIV-induced upregulation of immune response genes in human kidney cells. These data demonstrate that darunavir protects against HIV-induced renal injury via mechanisms that are independent of inhibition of HIV protease.

Rosuvastatin preserves renal function and lowers cystatin C in HIV-infected subjects on antiretroviral therapy: the SATURN-HIV trial.

BACKGROUND: In chronic human immunodeficiency virus (HIV) infection, plasma cystatin C may be influenced by factors other than glomerular filtration rate such as inflammation. Statins may improve cystatin C by improving glomerular function or by decreasing inflammation. METHODS: The Stopping Atherosclerosis and Treating Unhealthy Bone With Rosuvastatin in HIV (SATURN-HIV) trial randomized 147 patients on stable antiretroviral therapy (ART) with low-density lipoprotein cholesterol ≤130 mg/dL to blinded 10 mg daily rosuvastatin or placebo. We analyzed relationships of baseline and 0- to 24-week changes in plasma cystatin C concentration with measures of vascular disease, inflammation, and immune activation. RESULTS: Median age was 46 (interquartile range, 40-53) years; 78% were male, 68% African American. Tenofovir and protease inhibitors were used in 88% and 49% of subjects, respectively. Baseline cystatin C was associated with higher carotid intima-media thickness and epicardial adipose tissue independent of age, sex, and race. Biomarkers of endothelial activation and inflammation were associated with cystatin C in a multivariable model independent of creatinine-based estimated glomerular filtration rate (eGFRcr). After 24 weeks, statin use slowed mean eGFRcr decline (1.61 vs -3.08 mL/minute/1.73 m(2) for statin vs placebo; P = .033) and decreased mean cystatin C (-0.034 mg/L vs 0.010 mg/L; P = .008). Within the statin group, changes in cystatin C correlated with changes in endothelial activation, inflammation, and T-cell activation. CONCLUSIONS: Rosuvastatin 10 mg daily reduces plasma cystatin C and slows kidney function decline in HIV-infected patients on ART. Reductions in cystatin C with statin therapy correlate with reductions in inflammatory biomarkers. Relationships between cystatin C, kidney function, and cardiovascular risk in HIV may be mediated in part by inflammation. Clinical Trials Registration. NCT01218802.

Rapamycin-induced modulation of miRNA expression is associated with amelioration of HIV-associated nephropathy (HIVAN).

Recent studies suggested that miRNAs are involved in the development of the pathogenesis of HIV-associated nephropathy (HIVAN). Rapamycin, a widely used mTOR inhibitor, has been demonstrated to slow down the progression of HIVAN. However, the role of miRNA in the regulation of these processes has not been investigated so far. In the current study, we have used a microarray-based approach in combination with real-time PCR to profile the miRNA expression patterns in rapamycin-treated HIVAN mice (Tg26). Our results demonstrated that 19 miRNAs belonging to 13 different families expressed differentially in renal tissues of rapamycin-receiving Tg26 mice when compared to Tg26 mice-receiving saline only. The patterns of miRNAs expression in rapamycin-receiving Tg26 mice took a reverse turn. These miRNAs were classified into 8 functional categories. In in vitro studies, we examined the expression of specific miRNAs in HIV-1 transduced human podocytes (HIV/HPs). HIV/HPs displayed attenuation of expression of miR-99a, -100a, -199a and miR-200, whereas, rapamycin inhibited this effect of HIV. These findings suggest that rapamycin-mediated up-regulation of specific miRNAs could contribute to amelioration of renal lesions in HIVAN mice.

Can we cure HIV-1-associated nephropathy in transgenic mice?

HIV-1-associated nephropathy (HIVAN) is a rapidly progressive form of focal segmental glomerulosclerosis. HIV transgenic mice can develop a HIVAN-like renal disease. Zhong et al. show that the oral administration of a cyclic nucleotide phosphodiesterase 4 inhibitor and a retinoic acid receptor-α agonist can prevent the development of HIVAN in transgenic mice, acting through a cAMP-dependent mechanism that is independent of HIV-1 genes. These findings suggest that endogenous host factors play a critical role in HIVAN.

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 phosphodiesterase 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.

[Kidney and HIV infection]. / Rein et infection par le virus de l'immunodéficience humaine.

Screening of chronic kidney disease (CKD) that includes estimation of the glomerular filtration rate (GFR) and evaluation proteinuria should be performed in all HIV-infected patients and these parameters have to be monitored annually in patients at higher risk for CKD. Black patients have a genetic predisposition to develop HIV-associated nephropathy. Suppression of HIV viral replication with antiretroviral therapy prevents the development of HIV-associated nephropathy or halts its progression. Kidney biopsy remains the most informative diagnosis test to differentiate various forms of kidney diseases in HIV-infected patients. Dosing antiretroviral agents with kidney metabolism should be adjusted when eGFR is bellow 50 mL/min/1.73 m(2). eGFR and serum phosphorus at baseline and during treatment should be carefully assessed in patients receiving tenofovir. Proximal renal tubular toxicity must be further evaluated in the presence of eGFR decrease and/or hypophosphatemia under tenofovir therapy.

Secondary complications and co-infections in the HIV-infected adolescent in the antiretroviral era.

PURPOSE OF REVIEW: The number of HIV-infected adolescents is increasing dramatically. With combination antiretroviral therapy, they are expected to live well into adulthood. However, complications are emerging at a higher rate in the HIV-infected population compared to the general population. HIV-infected adolescents are also at a high risk of sexually transmitted co-infections. This article reviews the main secondary complications and co-infections in the HIV-infected adolescent. RECENT FINDINGS: HIV-infected adolescents are at a high risk of sexually transmitted infections. A careful, age-appropriate and developmentally appropriate inquiry into the individual's sexual behavior to assess risk is paramount, in addition to regular screening at medical visits. Treating co-infections is not only important for HIV-infected individuals, but also limits HIV transmission to others. In addition, monitoring and addressing modifiable secondary risk factors for complications such as renal disease, osteopenia or osteoporosis, and cardiovascular disease are critical, well before the onset of clinically apparent disease. Using antiretroviral therapy to suppress viral replication and inflammation appears to be a promising strategy for decreasing secondary complication risk, and likely overshadows the toxicities associated with the long-term use of certain antiretrovirals. SUMMARY: Assessing and addressing the risk of secondary complications and co-infections in the HIV-infected adolescent is crucial for optimal length and quality of life.

Complications of HIV infection: a systems-based approach.

Patients with human immunodeficiency virus (HIV) infection often develop multiple complications and comorbidities. Opportunistic infections should always be considered in the evaluation of symptomatic patients with advanced HIV/AIDS, although the overall incidence of these infections has decreased. Primary care of HIV infection includes the early detection of some complications through screening at-risk and symptomatic patients with routine laboratory monitoring (e.g., comprehensive metabolic and lipid panels) and validated tools (e.g., the HIV Dementia Scale). Treatment of many chronic complications is similar for patients with HIV infection and those without infection; however, combination antiretroviral therapy has shown benefit for some conditions, such as HIV-associated nephropathy. For other complications, such as cardiovascular disease and lipoatrophy, management may include switching antiretroviral regimens to reduce exposure to HIV medications known to cause toxicity.

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.

The morbidity and mortality associated with kidney disease in an HIV-infected cohort in Puerto Rico.

INTRODUCTION: Nephropathy in HIV-infected patients has been associated with progression to AIDS and death. The virus, several comorbid conditions and certain medications may contribute to the development and progression of kidney disease. METHODS: This study analyzed data collected from HIV-infected persons enrolled in a HIV registry in Puerto Rico during January 1998 through September 2006. Demographic factors, clinical manifestations, laboratory findings at enrollment, and antiretroviral therapy (ART) prescriptions were compared between patients with and without kidney disease. Death status and cause of death by December 2006 were also evaluated and compared. RESULTS: The study included 1,283 subjects, 69.0% male, 39.7% injecting drug users, 19.5% hepatitis C infected, 6.5% with diabetes mellitus (DM-2), 11.6% had hypertension (HTN) and 9.0% had kidney disease. Patients with kidney disease had significantly higher (P < .05) HIV viral load mean (273,499 vs. 202,858 copies/mL), CD4 T-cell count < 200 (57.0% vs. 44.4%), underweight (22.9% vs. 10.9%), DM-2 (13.9% vs. 5.8%), HTN (27.8% vs 10.0%) and mortality (15.9 vs 5.7 deaths per 100 years of follow-up) than those without it. Cox proportional hazard analysis showed that patients with kidney disease had a higher mortality risk (2.1) after controlling for age, sex, HIV risk factor, ART prescription in the last year and HIV disease duration. CONCLUSIONS: This study demonstrated a substantial disparity in mortality for Puerto Rican HIV-infected patients with nephropathy. Kidney disease preventive strategies that include aggressive control of HIV-infection and chronic medical conditions, such as hypertension and diabetes, are recommend as an approach to reduce this health disparity.

Proton magnetic resonance spectroscopy reveals neuroprotection by oral minocycline in a nonhuman primate model of accelerated NeuroAIDS.

BACKGROUND: Despite the advent of highly active anti-retroviral therapy (HAART), HIV-associated neurocognitive disorders continue to be a significant problem. In efforts to understand and alleviate neurocognitive deficits associated with HIV, we used an accelerated simian immunodeficiency virus (SIV) macaque model of NeuroAIDS to test whether minocycline is neuroprotective against lentiviral-induced neuronal injury. METHODOLOGY/PRINCIPAL FINDINGS: Eleven rhesus macaques were infected with SIV, depleted of CD8+ lymphocytes, and studied until eight weeks post inoculation (wpi). Seven animals received daily minocycline orally beginning at 4 wpi. Neuronal integrity was monitored in vivo by proton magnetic resonance spectroscopy and post-mortem by immunohistochemistry for synaptophysin (SYN), microtubule-associated protein 2 (MAP2), and neuronal counts. Astrogliosis and microglial activation were quantified by measuring glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (IBA-1), respectively. SIV infection followed by CD8+ cell depletion induced a progressive decline in neuronal integrity evidenced by declining N-acetylaspartate/creatine (NAA/Cr), which was arrested with minocycline treatment. The recovery of this ratio was due to increases in NAA, indicating neuronal recovery, and decreases in Cr, likely reflecting downregulation of glial cell activation. SYN, MAP2, and neuronal counts were found to be higher in minocycline-treated animals compared to untreated animals while GFAP and IBA-1 expression were decreased compared to controls. CSF and plasma viral loads were lower in MN-treated animals. CONCLUSIONS/SIGNIFICANCE: In conclusion, oral minocycline alleviates neuronal damage induced by the AIDS virus.

Ubisol-Aqua: coenzyme Q10 prevents antiretroviral toxic neuropathy in an in vitro model.

BACKGROUND: Peripheral neuropathy is the dose-limiting toxicity of stavudine and didanosine (nucleoside analogs used in HIV treatment) and is attributed to mitochondrial toxicity from these drugs. Acetyl L-carnitine (ALC) and co-enzyme Q(10) are proposed as neuropathy treatments, but evidence to support these is limited. METHODS: We examined ALC and a water-soluble formulation of co-enzyme Q(10) (H(Q)O) for the prevention of d4T and ddI neurotoxicity using cultured fetal rat DRG as an in vitro model. RESULTS: DdI (33microM) and d4T (50microM) caused clear toxicity (impaired neurite growth) by day 8 of DRG culture. H(Q)O at concentrations 1-100microM completely prevented the toxicity of 33microM ddI in vitro and ALC at concentrations 1-100 microM substantially (but incompletely) prevented ddI toxicity in this model. In contrast, ALC was ineffective at all concentrations tested for preventing the toxicity of 50microM d4T. H(Q)O showed dose-dependent efficacy for preventing d4T toxicity. H(Q)O (1microM) partially prevented d4T toxicity while 10 and 100microM H(Q)O completely prevented d4T toxicity in this model. CONCLUSIONS: We find H(Q)O is superior to ALC for preventing the neurotoxicity of d4T (the HIV treatment most associated with neuropathy) and ddI in vitro. Further study is needed to clarify any clinical role for co-enzyme Q(10) co-administration with d4T and ddI and to assess whether this compound may have a role in treating established cases of neuropathy.

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.

HIV-associated nephropathy in the era of antiretroviral therapy.

With improved survival in the era of antiretroviral therapy, kidney disease has emerged as an important complication of Human Immunodeficiency Virus (HIV) infection and antiretroviral therapy. The classic kidney disease of HIV infection, HIV-associated nephropathy, occurs almost exclusively in patients of African descent. HIV-associated nephropathy is characterized by collapsing focal segmental glomerulosclerosis with associated tubular dilatation and interstitial inflammation, although the histology may be more subtle in patients receiving antiretroviral therapy. Renal epithelial cells are infected by HIV-1, which results in epithelial cell proliferation and induction of local inflammatory pathways. Even with appropriate therapy, the kidney is a reservoir for HIV-1. Although the widespread introduction of antiretroviral therapy has had a beneficial impact on the epidemiology of HIV-associated nephropathy, the burden of kidney disease is likely to increase as a result of antiretroviral toxicity, reduction in competing mortality risks, and the increasing prevalence of HIV-1 infection in patients at risk for kidney disease.

Angiotensin II type 1 receptor blockade inhibits the development and progression of HIV-associated nephropathy in a mouse model.

HIV-associated nephropathy (HIVAN) is characterized by a collapsed glomerular capillary tuft with hyperplasia and hypertrophy of podocytes. Recently generated were conditional transgenic mice (podocin/Vpr) that express one of the HIV-1 accessory genes, vpr, selectively in podocytes using podocin promoter and Tet-on system. These transgenic mice developed renal injury similar to HIVAN when treated with doxycycline for 8 to 12 wk. This study demonstrated that nephron reduction by heminephrectomy markedly enhanced phenotypic changes of podocytes and led to severe FSGS within 4 wk. Nephrotic-range proteinuria was observed already at 2 wk, together with dedifferentiation and dysregulation of podocytes, indicated by decreased expression of nephrin, synaptopodin, and Wilms' tumor 1 protein and increased expression of Ki-67. The acceleration of phenotypic changes of podocytes, proteinuria, and subsequent glomerulosclerosis by heminephrectomy was almost completely inhibited by angiotensin II type 1 receptor (AT1R) blocker olmesartan. In contrast, the renoprotective effect of the calcium channel antagonist azelnidipine was minimal, although it lowered systemic BP to the same level as olmesartan, demonstrating that the inhibitory effect of AT1R blocker was independent of systemic BP. Olmesartan also reduced proteinuria and prevented glomerulosclerosis even by the delayed treatment, which was initiated after the podocyte injury appeared. These data suggest that nephron reduction exaggerates podocyte injury and subsequent glomerulosclerosis, possibly through glomerular hypertension, in the mouse model of HIVAN. AT1R blockade could be beneficial in the treatment of HIVAN by ameliorating podocyte injury by avoiding the vicious cycle of nephron reduction and glomerular hypertension.

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.

HIV/AIDS--dominant player in chronic kidney disease.

HIV-associated nephropathy (HIVAN) is now the third leading cause of end-stage renal disease (ESRD) in African Americans between the ages of 20 and 64 years. Statistics in the United States estimate the incidence of HIVAN to be between 3.5% and 12%. The estimated number of those living with HIV worldwide is 37.4 million, with 26 million in Africa. If the US data for HIVAN were extrapolated to Africa, between 0.9 and 3.1 million people would be predicted to have HIVAN. These figures predict an unprecedented (and possibly underestimated) burden of chronic kidney disease (CKD) in Africa, especially if we take into account the socioeconomic associations with CKD for the African continent. This potentially large number of patients poses daunting logistic, financial, and ethical issues for physicians and nephrologists practicing in Africa. Preventing chronic kidney disease due to HIV in Africa should become a major priority. This would enable early detection and treatment of HIVAN in order to prevent or delay progression to ESRD. As HIV infection is a risk factor for the development of CKD, the HIV Medicine Association of the Infectious Diseases Society of America recommends screening for CKD in HIV-infected patients; screening tests should be similar to those for patients with diabetes mellitus to detect early renal involvement. Preventive strategies need to be determined; prospective studies including antiretroviral therapy, angiotensin-converting enzyme inhibitors, and other therapeutic agents are required.

Highly active antiretroviral therapy and the incidence of HIV-1-associated nephropathy: a 12-year cohort study.

OBJECTIVE: to assess temporal changes in the incidence of human immunodeficiency virus-1-associated nephropathy (HIVAN), and the association with use of highly active antiretroviral therapy (HAART). METHODS: HIVAN incidence and risk factors were assessed in 3976 HIV-1-infected individuals followed in clinical cohort in Baltimore, Maryland, USA from 1989 to 2001. The incidence of HIVAN, defined by biopsy or a conservative uniformly applied clinical coding protocol, was expressed in terms of person-years, and Poisson regression was used for multivariate analysis. RESULTS: Ninety-four patients developed HIVAN over the course of the study for an incidence of 8.0 per 1000 person-years [95% confidence interval (CI), 6.5 to 9.8]. African American race and advanced immunosuppression were strongly associated with HIVAN risk. HIVAN incidence declined significantly in 1998-2001 compared with 1995-1997. Among patients with a prior diagnosis of AIDS, HIVAN incidence was 26.4, 14.4, and 6.8 per 1000 person-years in patients not receiving antiretroviral therapy, treated with nucleoside analogue therapy only, or treated with HAART, respectively (P < 0.001 for trend). In multivariate analysis, HIVAN risk was reduced 60% (95% CI, -30 to -80%) by use of HAART, and no patient developed HIVAN when HAART had been initiated prior to the development of AIDS. CONCLUSION: HAART was associated with a substantial reduction in HIVAN incidence. Additional follow-up will be needed to determine if renal damage in susceptible individuals is halted or merely slowed by HAART, particularly when control of viremia is incomplete or intermittent.