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.

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.

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.

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.

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.

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.

Human immunodeficiency virus infection and renal failure

Renal manifestations are an important component of HIV disease. Renal disease significantly contributes to morbidity and mortality in patients with HIV. Great progress has been made in identifying specific glomerular lesions and its pathogenesis. Newer antiretroviral agents offer great promise in preventing renal disease and also in patients with established HIVAN. Survival of patients with HIV and ESRD (irrespective of cause) who are receiving RRT continues to improve over the years. Acute reversible renal failure, a preventable complication, is also declining in hospitalized HIV patients. More and more physicians, who in the past were reluctant to care for patients with HIV and renal failure because of grim prognosis, are now becoming familiar with the renal sequelae and are encouraged by recent favorable results. As knowledge about viruses is expanding, the proper use of newer highly effective antiretroviral and other agents in complicated patients should further improve both the survival and quality of life in patients with HIV infection and renal disease.

Captopril prevents nephropathy in HIV-transgenic mice

Transgenic mice (T26) bearing the envelope, regulatory, and accessory genes of HIV- I develop renal disease resembling human HIV-associated nephropathy (HIVAN). Effects of vehicle (VEH) and the angiotensin-converting enzyme inhibitor captopril (CAP) were examined in wild-type (WT) or T26 mice treated from 7 to 100 d of age. Mortality was lower in CAP T26 mice (30 mg/kg: 8%; 100 mg/kg: 12%) than VEH T26 mice (52%). The urinary protein/creatinine ratio was increased in VEH T26 mice (19.5+/-7.60) versus WT mice (6.1+/-0.83), but not in low-dose (7.3+/-0.94) or high-dose (8.2+/-1.02) CAP T26 mice. Blood urea nitrogen was higher in VEH T26 mice (52+/-16.2 mg/dl) than VEH WT mice (24+/-0.8). Blood urea nitrogen was also elevated in CAP WT (high dose: 43+/-2.1 mg/dl) and T26 mice (high dose: 42+/-2.4 mg/dl). Glomerular injury was higher in VEH T26 mice (6.8+/-0.58) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 1.1+/-0.17; high dose: 0.7+/-0.13). Tubulointerstitial injury was also greater in VEH T26 mice (1.1+/-0.10) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 0.4+/-0.10; high dose: 0.3+/-0.10). These data validate recent nonrandomized studies of captopril in HIV-infected patients, and suggest that an angiotensin-converting enzyme substrate is an important mediator in HIVAN. A randomized placebo-controlled trial of captopril in HIVAN may be warranted.

Preventive health care for adults with HIV infection

OBJECTIVE

To assess the level of evidence for preventive health interventions for adults with human immunodeficiency virus (HIV) infection.

DATA SOURCES

A MEDLINE literature search for each intervention, supplemented by reviewing conference proceedings and the recommendations of experts.

STUDY SELECTION

English-language studies of interventions that contribute to one of the following goals were reviewed: (1) prevention of complications of HIV infection; (2) early detection of complications, before symptoms develop, at a stage in which early treatment could lead to improved outcome; (3) slowing of HIV disease progression; (4) reduction in the risk of transmission of infectious agents, such as HIV itself; and (5) prevention of psychological distress and improvement in the quality of life.

DATA EXTRACTION

The importance of interventions and quality of supporting evidence were evaluated using criteria modified from the US Preventive Services Task Force.

DATA SYNTHESIS

Existing evidence strongly supports the efficacy of some preventive measures: primary and secondary Pneumocystis carinii pneumonia prophylaxis; secondary prophylaxis of Cryptococcus, Toxoplasma, and cytomegalovirus infections; tuberculin testing, with chemotherapy for individuals with positive test results; syphilis screening; Papanicolaou tests; educational measures to reduce the transmission of HIV and other infections; T-lymphocyte monitoring; and antiretroviral therapy in selected patients. Recommended measures of possible, but less certain, effectiveness include vaccines to prevent influenza, Haemophilus influenzae, pneumococcal, and hepatitis B infections; prophylaxis for recurrent esophageal and vaginal candidiasis; primary prophylaxis of Mycobacterium avium complex; tuberculosis prophylaxis for anergic, high-risk individuals; routine physical examination; screening for gonorrhea and Chlamydia in high-risk women; monitoring Toxoplasma titers, complete blood cell counts, and serum chemistry values; attempting to maintain weight through nutritional interventions; and exercise. Mental health and substance abuse interventions are probably very important, but documentation of their benefits is limited. Some measures require further study before they can routinely be recommended, including vitamin and mineral supplementation; specific nutritional diets; and laboratory tests, other than CD4 counts, for monitoring disease progression.

CONCLUSIONS

Persons with HIV infection have different stage-specific health maintenance needs that form an important part of comprehensive care for people in all stages of infection.