Protease inhibitors are associated with a slowed progression of HIV-related renal diseases

The effects of add-on corticosteroids on renal outcomes in patients with biopsy proven HIV associated nephropathy: a single centre study from South Africa

BACKGROUND

The aim of this study was to assess, the efficacy and safety of add-on corticosteroids to antiretroviral therapy [ART] in patients with biopsy proven HIV associated nephropathy.

METHODS

All included patients had histological evidence of either collapsing or non-collapsing focal segmental glomerulosclerosis (FSGS) or podocyte and/or parietal cell hypertrophy or hyperplasia. All patients had evidence of tubulointerstitial inflammation with microcysts. Patients were randomized to ART with the addition of 1 mg/kg of corticosteroids [ART+C] or remained in the group [ART Alone] and followed for 2 years. A repeat biopsy was performed at 6 months.

RESULTS

Twenty-one patients were randomized to [ART+C] and 17 to [ART Alone]. The baseline estimated glomerular filtration rate (eGFR) was significantly lower in the [ART+C] vs. [ART Alone] group [35mls/min/1.73m2 vs. 47 mls/min/1.73m2, p = 0.015]. The [ART+C] cohort had a statistically significant improvement in median (eGFR) from baseline to last follow up compared with [ART Alone] i.e. [Δ = 25mls/min (IQR: 15;51) vs 9 mls/min (IQR: 0-24), p = 0.008]. There were no statistically significant differences between the groups when proteinuria and histology were analyzed. There were 8 deaths during the trial period, 7 from [ART+C] (Log rank p = 0.071).

CONCLUSIONS

In the [ART+C] cohort there was a significant improvement in eGFR over 2-years with increased mortality. Routine corticosteroid use cannot currently be recommended. Further investigation to define which subgroup of this cohort would safely benefit from the positive effects is required.

TRIAL REGISTRATION

ISRCTN study ID ( 56112439 ] was retrospectively registered on the 5 September 2018.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Impact of antiretroviral therapy on renal function among HIV-infected Tanzanian adults: a retrospective cohort study

Background

Data regarding the outcomes of HIV-infected adults with baseline renal dysfunction who start antiretroviral therapy are conflicting.

Methods

We followed up a previously-published cohort of HIV-infected adult outpatients in northwest Tanzania who had high prevalence of renal dysfunction at the time of starting antiretroviral therapy (between November 2009 and February 2010). Patients had serum creatinine, proteinuria, microalbuminuria, and CD4⁺ T-cell count measured at the time of antiretroviral therapy initiation and at follow-up. We used the adjusted Cockroft-Gault equation to calculate estimated glomerular filtration rates (eGFRs).

Results

In this cohort of 171 adults who had taken antiretroviral therapy for a median of two years, the prevalence of renal dysfunction (eGFR <90 mL/min/1.73 m²) decreased from 131/171 (76.6%) at the time of ART initiation to 50/171 (29.2%) at the time of follow-up (p<0.001). Moderate dysfunction (eGFR<60 mL/min/1.73 m²) decreased from 21.1% at antiretroviral therapy initiation to 1.1% at follow-up (p<0.001), as did the prevalence of microalbuminuria (72% to 44%, p<0.001). Use of tenofovir was not associated with renal dysfunction at follow-up.

Conclusion

Mild and moderate renal dysfunction were common in this cohort of HIV-infected adults initiating antiretroviral therapy, and both significantly improved after a median follow-up time of 2 years. Our work supports the renal safety of antiretroviral therapy in African adults with mild-moderate renal dysfunction, suggesting that these regimens do not lead to renal damage in the majority of patients and that they may even improve renal function in patients with mild to moderate renal dysfunction.

High prevalence of renal dysfunction and association with risk of death amongst HIV-infected Ghanaians

OBJECTIVES

To determine the prevalence of HIV-associated renal dysfunction (RD), identify risk factors for RD and explore the association between baseline renal function and mortality in an HIV-infected population in Ghana.

METHODS

Creatinine clearance (CrCl) or estimated glomerular filtration rate (eGFR) was calculated in patients attending an HIV clinic between 2004 and 2011 using Cockcroft-Gault, MDRD and CKD-EPI formulae. Logistic regression analysis was used to identify risk factors associated with RD and Kaplan-Meier/Cox proportional regression analyses to explore associations between baseline CrCl/eGFR and subsequent mortality.

RESULTS

In 3137 patients starting antiretroviral therapy (ART) the frequency (95%-CI) of RD, defined by CrCl <60 ml/min/1.73 m(2) using Cockroft-Gault formula was 38.8% (37.1-40.5%). RD prevalence in a sub-population of 238 patients, including proteinuria in the definition, was 15.3% (10.3-22.1%) in ART-treated and 43.6% (34.0-53.7%) in ART-naïve patients. RD at baseline was associated with increasing age, low CD4 counts, advanced WHO stage and female gender. Cox proportional hazard analysis identified an increased hazard of death with decreasing CrCl, HR 1.46 (1.31-1.63) for each tertile lower than CrCl of 90 ml/min/1.73 m(2).

CONCLUSIONS

RD is very common in HIV-infected ART-naïve Ghanaians, and associated with increased risk of mortality. Screening and monitoring of RD is important in this setting, particularly as tenofovir use increases.

Kidney Disease in HIV-Infected Persons

Kidney disease is more prevalent among persons living with HIV, and may arise from a combination of comorbidities, co-infections, and medication-associated toxicities. Additional effects of HIV-1 viral replication, immunodeficiency and genetic factors also contribute to kidney disease. As is true in the general population, persons of African descent exhibit a disproportionate risk for severe kidney disease. Antiretroviral therapy (ART) modifies the natural history of HIV-associated nephropathy (HIVAN), and renal benefits of ART may not be limited to persons with HIVAN. Robust associations between proteinuria and cardiovascular disease imply that common mechanisms of vascular endothelial dysfunction may contribute to both processes.

Risk factors for chronic kidney disease in a large cohort of HIV-1 infected individuals initiating antiretroviral therapy in routine care

OBJECTIVE

To examine long-term effects of antiretroviral therapy (ART) on kidney function, we evaluated the incidence and risk factors for chronic kidney disease (CKD) among ART-naive, HIV-infected adults and compared changes in estimated glomerular filtration rates (eGFR) before and after starting ART.

METHODS

Multicenter observational cohort study of patients with at least one serum creatinine measurement before and after initiating ART. Cox proportional hazard models, and marginal structure models examined CKD risk factors; mixed-effects linear models examined eGFR slopes.

RESULTS

Three thousand, three hundred and twenty-nine patients met entry criteria, contributing 10 099 person-years of observation on ART. ART was associated with a significantly slower rate of eGFR decline (from -2.18 to -1.37 ml/min per 1.73 m per year; P = 0.02). The incidence of CKD defined by eGFR thresholds of 60, 45 and 30 ml/min per 1.73 m was 10.5, 3.4 and 1.6 per 1000 person-years, respectively. In adjusted analyses black race, hepatitis C coinfection, lower time-varying CD4 cell count and higher time-varying viral load on ART were associated with higher CKD risk, and the magnitude of these risks increased with more severe CKD. Tenofovir and a ritonavir-boosted protease inhibitor (rPI) was also associated with higher CKD risk [hazard odds ratio for an eGFR threshold <60 ml/min per 1.73 m: 3.35 (95% confidence interval (CI) = 1.40-8.02)], which developed in 5.7% of patients after 4 years of exposure to this regimen-type.

CONCLUSION

ART was associated with reduced CKD risk in association with CD4 cell restoration and plasma viral load suppression, despite an increased CKD risk that was associated with initial regimens that included tenofovir and rPI.

The spectrum of HIV-related nephropathy in children

BACKGROUND

Despite the burden of human immunodeficiency virus (HIV) disease in Southern Africa, there have been few reports of HIV-related nephropathy in children. This study outlines the spectrum of HIV-1-related kidney diseases of children in KwaZulu-Natal, South Africa.

METHODS

A review of the clinical presentation, laboratory and histopathological findings of children diagnosed with HIV-related nephropathy.

RESULTS

Forty-nine out of 71 children (1-16 years old) with HIV-1 related nephropathy underwent kidney biopsy. The most common histopathological finding was focal segmental glomerulosclerosis (FSGS), which was present in 32 (65.3%) children; 13 (26.5%) having collapsing glomerulopathy and 19 (38.8%) classic FSGS. The majority of patients showed haematological (86.4%) and electrolyte abnormalities (69.4%). Renal impairment was present in 41% of patients on initial presentation. However, end-stage kidney disease was present in only 4% of these patients. All patients were treated with highly active anti-retroviral therapy (HAART), the majority (79.6%) showed decreased proteinuria with 38.8% having complete remission.

CONCLUSIONS

This study, one of the largest series of children reported from Africa, demonstrates that nephrotic syndrome due to HIV-associated nephropathy (HIVAN) is the commonest presentation of HIV-related nephropathy in childhood. Highly active anti-retroviral therapy in combination with angiotensin-converting enzyme antagonists is highly effective in decreasing proteinuria and preserving renal function.

A patient with HIV infection presenting with diffuse membranous glomerulonephritis in a country with a low HIV prevalence--remarkable remission with therapy

The most common manifestation of HIV in the kidney is HIV-associated nephropathy (HIVAN). In this report, we describe the first documented case of membranous glomerulonephritis in an HIV-positive individual in Turkey, the country with the lowest HIV prevalence in the region. The case occurred in an HIV-positive, hepatitis C (HCV)-negative, and hepatitis B (HBV)-negative Caucasian male, who presented with nephrotic-range proteinuria. The patient had a favorable response to HAART and an angiotensin-receptor blocker.

The New Epidemiology of HIV-Related Kidney Disease

HIV-related kidney disease has been associated with significant morbidity and mortality in the HIV population. It is clear that the epidemiology of HIV-related kidney disease has changed dramatically since the first case reports in 1984. During these early years, the predominant etiology of kidney disease in HIV was recognized as HIV-associated nephropathy (HIVAN), an aggressive form of kidney disease with a high rate of progression to end-stage renal disease (ESRD). Subsequently, with the widespread use of combination antiretroviral therapy (cART), there was a dramatic decrease in the incidence of ESRD attributed to HIV/AIDS. Although the incidence of HIV-related ESRD has plateaued in the last 15 years, the prevalence has continued to increase because of improved survival. Available prevalence estimates do not include HIV-infected individuals with comorbid ESRD, although there is growing evidence that the epidemiology of kidney disease in the HIV-infected population has changed. This article reviews the impact of risk factors such as race, diabetes mellitus, hypertension, hepatitis C virus coinfection, and the chronic use of cART on the changing epidemiology of HIV-related kidney disease. Additionally in this review, we propose potential areas of translational research that will help to further characterize HIV-related kidney disease in the 21^st century.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Treatment of HIV-associated nephropathies

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

Impact of comorbidities and drug therapy on development of renal impairment in a predominantly African American and Hispanic HIV clinic population

Purpose

Renal impairment in human immunodeficiency virus (HIV)-infected patients could potentially be caused by many factors. HIV-related renal impairment risks have been little studied in African Americans and Hispanics. We investigated the impact of HIV itself, highly active antiretroviral therapy (HAART), comorbidities, and non-HIV-related drug treatment on glomerular filtration rate in a predominantly African American/Hispanic HIV-infected population who had received HAART for at least one year. This study was a retrospective electronic medical record database evaluation of renal impairment risks in a largely African American/Hispanic HIV population obtaining medical care at an HIV clinic in Dallas, Texas.

Methods

Proportional hazards models were used to investigate an association between an estimated glomerular filtration rate decrease >25% from baseline (ie, renal impairment) and demographics, antiretroviral/nonantiretroviral medications, comorbidities (hypertension, diabetes mellitus, hepatitis C virus [HCV] infection, hepatitis B virus [HBV] infection), CD4+ counts, viral load, and duration patients were monitored at the clinic (time on study).

Results

In total, 323 patients were evaluated: 82% males; 61% African American/12% Hispanic/19% Caucasian; mean age 37.9 years (standard deviation [SD] 8.5); 6% HBV-positive; 34% HCV-positive; 29% hypertensive; 3% diabetic; 52% tenofovir-treated; mean weight 75.4 kg (SD, 15.4); mean estimated glomerular filtration 114.5 mL/min/1.73 m² (SD, 36.7) using the Modification of Diet in Renal Disease (MDRD) calculation method; mean creatinine clearance (from which estimated glomerular filtration was extrapolated) by the Cockcroft-Gault calculation method 120.6 mL/min/1.73 m² (SD, 41.2); mean time on study 2.7 years (SD, 1.0 year). An estimated glomerular filtration rate decrease of >25% from baseline was significantly associated with time on study (P = 0.0017; hazards ratio [HR] = 0.999) and hypertension (HR = 1.706; P = 0.0158) by the MDRD method, and with age (HR = 1.039; P = 0.0077), weight (HR = 0.987; P = 0.0023), and time on study (HR = 0.999; P = 0.0043) by extrapolation of Cockcroft-Gault creatinine clearance calculation. No specific HAART agent was associated with significant renal impairment risk by the definition used in this study.

Conclusion

This retrospective database study showed time on study, hypertension, weight, and age to be the only significant predictors of an estimated glomerular filtration rate decrease >25% from baseline.

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

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

Estimated glomerular filtration rate, chronic kidney disease and antiretroviral drug use in HIV-positive patients

OBJECTIVES

Chronic kidney disease (CKD) in HIV-positive persons might be caused by both HIV and traditional or non-HIV-related factors. Our objective was to investigate long-term exposure to specific antiretroviral drugs and CKD.

DESIGN

A cohort study including 6843 HIV-positive persons with at least three serum creatinine measurements and corresponding body weight measurements from 2004 onwards.

METHODS

CKD was defined as either confirmed (two measurements >or=3 months apart) estimated glomerular filtration rate (eGFR) of 60 ml/min per 1.73 m or below for persons with baseline eGFR of above 60 ml/min per 1.73 m or confirmed 25% decline in eGFR for persons with baseline eGFR of 60 ml/min per 1.73 m or less, using the Cockcroft-Gault formula. Poisson regression was used to determine factors associated with CKD.

RESULTS

Two hundred and twenty-five (3.3%) persons progressed to CKD during 21 482 person-years follow-up, an incidence of 1.05 per 100 person-years follow-up [95% confidence interval (CI) 0.91-1.18]; median follow-up was 3.7 years (interquartile range 2.8-5.7). After adjustment for traditional factors associated with CKD and other confounding variables, increasing cumulative exposure to tenofovir [incidence rate ratio (IRR) per year 1.16, 95% CI 1.06-1.25, P < 0.0001), indinavir (IRR 1.12, 95% CI 1.06-1.18, P < 0.0001), atazanavir (IRR 1.21, 95% CI 1.09-1.34, P = 0.0003) and lopinavir/r (IRR 1.08, 95% CI 1.01-1.16, P = 0.030) were associated with a significantly increased rate of CKD. Consistent results were observed in wide-ranging sensitivity analyses, although of marginal statistical significance for lopinavir/r. No other antiretroviral drugs were associated with increased incidence of CKD.

CONCLUSION

In this nonrandomized large cohort, increasing exposure to tenofovir was associated with a higher incidence of CKD, as was true for indinavir and atazanavir, whereas the results for lopinavir/r were less clear.

HIV and kidney disease in sub-Saharan Africa

A wide clinical spectrum of renal diseases affects individuals with HIV. These conditions include acute kidney injury, electrolyte and acid-base disturbances, HIV-associated glomerular disease, acute-on-chronic renal disease and adverse side effects related to treatment of HIV. Studies employing varying criteria for diagnosis of kidney disease have reported a variable prevalence of these diseases in patients with HIV in sub-Saharan Africa: 6% in South Africa, 38% in Nigeria, 26% in Côte d'Ivoire, 28% in Tanzania, 25% in Kenya, 20-48.5% in Uganda and 33.5% in Zambia. Results from these studies also suggest that a broader spectrum of histopathological lesions in HIV-associated kidney disease exists in African populations than previously thought. Strategies to prevent or retard progression to end-stage renal disease of HIV-associated kidney conditions should include urinalysis and measurement of kidney function of all people with HIV at presentation. Renal replacement in the form of dialysis and transplantation should be implemented as appropriate. This Review focuses on the available evidence of renal diseases in patients with HIV infection in sub-Saharan Africa and offers practical guidelines to treat these conditions that also take into consideration challenges and obstacles that are specific to sub-Saharan Africa.

Renal disease in AIDS: it is not always HIVAN

Human immunodeficiency virus (HIV) infection can cause a broad spectrum of clinical manifestations, ranging from an asymptomatic carrier state to severe immunodeficiency. The most common renal lesion, HIV-associated nephropathy (HIVAN), is a sclerosing glomerulopathy. However, potentially reversible causes of renal disease in HIV-infected patients should also be considered. We describe two cases of patients with acquired immune-deficiency syndrome (AIDS) who presented with rapidly progressive renal failure but were found to have reversible etiologies. The first case was found to have syphilis and the second, disseminated histoplasmosis; their renal injury resolved after initiation of a third-generation cephalosporin antibiotic and amphotericin B, respectively.

HIV and CKD epidemiology

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

The treatment of HIV-associated nephropathy

Antiretroviral therapy (ART) preserves kidney function in patients with human immunodeficiency virus (HIV)-associated nephropathy (HIVAN). Emerging data also document substantial renal benefits of ART in the general HIV-infected population, which is associated in part with suppression of HIV-1 viral replication. The extent to which the response to ART differs in persons with HIVAN compared with those with other HIV-associated kidney disorders is unknown. Beneficial effects of corticosteroids and angiotensin-converting enzyme inhibitors on kidney function also are suggested by retrospective cohort studies and uncontrolled trials of patients with HIVAN. Underexposure to ART or inadequate ART dosing in HIV-infected patients with CKD may curtail the optimal benefits that may be derived from this therapy.

[Kidney diseases in HIV-infected patients]

HIV infection has become a global disease, both in geographic terms, since it has spread worldwide, and at the individual level since it affects every organ of the human body. Antiretroviral treatments, in countries where they are easily available, have modified HIV infection into a systemic chronic disease, the life expectancy of which is yet to be determined precisely. Treatments have dramatically changed the pattern of the disease and clinicians now have to face a number of new challenges. Kidneys, like all the other organs, can be involved in a great number of diseases in HIV-infected patients. We have voluntarily chosen to present "kidney diseases in HIV-infected patients" in their wider meaning, with a discussion of renal diseases that are directly caused by the virus, nephropathies due to frequent viral co-infections in HIV-infected patients such as HCV and HBV, nephropathies induced by anti-HIV, HBV and HCV therapies. Physicians in charge of HIV-infected patients should be aware of the key role they have to play in the screening for kidney abnormalities. This participates not only in improving patients' kidney prognosis but also their long-term general outcome. Renal screening strategies must refer to simple routine laboratory tests. Enclosed at the end of this article are a few suggestions for the renal management of situations that frequently occur in HIV infected patients (kidney dysfunction screening, serum creatinine increase and discovery of a proteinuria).

Pathogenesis of HIV-associated nephropathy

Human immunodeficiency virus-associated nephropathy (HIVAN) is a leading cause of end-stage renal disease in the HIV-1-seropositive population. HIVAN, which is characterized by heavy proteinuria and a rapid decline in renal function, is caused by infection and subsequent expression of viral genes in renal epithelial cells, although the exact mechanism of viral entry into these cells is unknown. The infected renal epithelium is a distinct compartment that supports the evolution of viral strains that may diverge from those found in the patient's blood. Research using animal models and in vitro studies has shown that vpr and nef are the HIV-1 genes most responsible for inducing the characteristic clinical and histopathologic syndrome of HIVAN. Dysregulation of several host factors, including mediators of inflammation, apoptosis, proliferation, transcription, and cell-cell interactions, are also critical factors in determining whether infection of the renal epithelium will lead to HIVAN. Additional research is required to delineate the mechanisms of HIVAN pathogenesis further so that more effective interventions can be implemented to prevent and treat this disease.

Interruption of antiretroviral therapy is associated with increased plasma cystatin C

BACKGROUND

Cystatin C has been proposed as an alternative marker of renal function. We sought to determine whether participants randomized to episodic use of antiretroviral therapy guided by CD4 cell count (drug conservation) had altered cystatin C levels compared with those randomized to continuous antiretroviral therapy (viral suppression) in the Strategies for Management of Antiretroviral Therapy trial, and to identify factors associated with increased cystatin C.

METHODS

Cystatin C was measured in plasma collected at randomization, 1, 2, 4, 8 and 12 months after randomization in a random sample of 249 and 250 participants in the drug conservation and viral suppression groups, respectively. Logistic regression was used to model the odds of at least 0.15 mg/dl increase in cystatin C (1 SD) in the first month after randomization, adjusting for demographic and clinical characteristics.

RESULTS

At randomization, mean (SD) cystatin C level was 0.99 (0.26 mg/dl) and 1.01 (0.28 mg/dl) in the drug conservation and viral suppression arms, respectively (P = 0.29). In the first month after randomization, 21.8 and 10.6% had at least 0.15 mg/dl increase in cystatin C in the drug conservation and viral suppression arms, respectively (P = 0.0008). The difference in cystatin C between the treatment arms was maintained through 1 year after randomization. After adjustment, participants in the viral suppression arm had significantly reduced odds of at least 0.15 mg/dl increase in cystatin C in the first month (odds ratio 0.42; 95% confidence interval 0.23-0.74, P = 0.0023).

CONCLUSION

These results demonstrate that interruption of antiretroviral therapy is associated with an increase in cystatin C, which may reflect worsened renal function.

Nephrotoxicity associated with antiretroviral therapy in HIV-infected patients

BACKGROUND

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

OBJECTIVE

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

METHODS

Current literature and HIV treatment guidelines are reviewed.

RESULTS/CONCLUSIONS

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

The effects of HIV type-1 viral suppression and non-viral factors on quantitative proteinuria in the highly active antiretroviral therapy era

Background

Proteinuria is associated with progressive renal disease and overall mortality in HIV-infected patients; however, the prevalence and correlates of quantitative pro-teinuria in the highly active antiretroviral therapy era are unknown.

Methods

Spot urine protein to creatinine (P/Cr) ratios, an accepted measure of quantitative daily proteinuria, were measured annually since 2002 in participants of the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort. We used linear regression models with general estimating equations to identify factors associated with the abnormal P/Cr thresholds of ≥0.2 and ≥1.0.

Results

Of the 2,857 participants (most of whom were receiving antiretroviral therapy) analysed, 16% and 3% had P/Cr levels ≥0.2 and ≥1.0, respectively, at first measurement. P/Cr levels did not change during a median follow-up of 3 years (interquartile range 2–4). Factors associated with P/Cr≥0.2 at any measurement included greater age, lower glomerular filtration rate, female sex, antiretroviral therapy prior to entry into parent randomized trial, HIV type-1 RNA level ≥400 copies/ ml, lower CD4+ T-cell count and history of hypertension, diabetes or hepatitis C coinfection (all P<0.04). Black race and higher non-high-density lipoprotein cholesterol levels were associated with P/Cr levels ≥1.0, but not with P/ Cr levels ≥0.2. Hepatitis B coinfection and current use of adefovir, indinavir and tenofovir were not associated with either of the P/Cr thresholds.

Conclusions

Both HIV-1 and non-HIV-1-related factors are associated with abnormal levels of proteinuria and identify those who are at a greater risk of worse clinical outcomes. Several of these factors are differentially associated with lower and higher proteinuria thresholds.

Predictors of renal outcome in HIV-associated nephropathy

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Research in HIV-related renal diseases lags behind their burden to the 'positive' community

Although outcomes for persons with HIV infection and renal disease have improved, the analysis by Choi et al. suggests that they remain similar to or worse than outcomes for persons with diabetes mellitus. This study should be used to frame the research resources that we devote to furthering knowledge in this area.

HIV-1 and HIV-Associated Nephropathy 25 Years Later

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

Infection and glomerulonephritis

Glomerular injury, occurring either as primary glomerular disease or as part of a systemic disease process, is usually a result of immune-mediated mechanisms. The morphologic reaction pattern has a diverse spectrum of appearance, ranging from normal by light microscopy in minimal change disease to crescentic forms of glomerulonephritis, with conspicuous disruption of the normal glomerular morphology. The mechanisms of glomerular immune deposit formation include trapping of circulating antigen-antibody complexes and the in situ formation of immune complexes within the glomerulus. While the majority of postinfectious immune-complex-mediated glomerulonephritides are believed to result from the deposition of circulating antigen-antibody complexes, preformed outside of the kidney and secondarily deposited in the kidney, the notion of forming in situ antigen-antibody complexes to either planted antigens or to integral structural components of the glomerulus, through "cross-reacting" autoimmune reactions, is gaining popularity in a variety of forms of glomerulonephritides. Patients with HIV infection may develop a spectrum of renal pathology, the glomerular manifestations of which include both antigen-antibody complex and nonimmune-complex-mediated pathogenetic mechanisms. Similarly, patients with Streptococcal infections, Hepatitis B virus, or Hepatitis C virus infection may develop a spectrum of glomerulonephritides, which are predominantly immune-complex-mediated. Therapy for glomerular diseases due to HIV, hepatitis B, or C virus infections remains a challenge.

HIV-1 infection and the kidney: an evolving challenge in HIV medicine

With the advent of highly active antiretroviral therapy (HAART), the incidence of opportunistic infections has declined substantially, and cardiovascular, liver, and renal diseases have emerged as major causes of morbidity and mortality in individuals with human immunodeficiency virus (HIV). Acute renal failure is common in HIV-infected patients and is associated with acute infection and medication-related nephrotoxicity. HIV-associated nephropathy is the most common cause of chronic kidney disease in HIV-positive African American populations and may respond to HAART. Other important HIV-associated renal diseases include HIV immune complex kidney diseases and thrombotic microangiopathy. The increasing importance of non-HIV-associated diseases, such as diabetes mellitus, hypertension, and vascular disease, to the burden of chronic kidney disease has been recognized, focusing attention on prevention and control of these diseases in HIV-positive individuals. HIV-positive individuals who experience progression to end-stage renal disease and who have undetectable HIV-1 viral loads while receiving HAART should be evaluated for renal transplant. Emerging evidence suggests that HIV-positive individuals may have graft and patient survival comparable to HIV-negative individuals. Several studies suggest that HIV-1 can potentially infect renal cells, and HIV transgenic mice have clarified the roles of a number of HIV proteins in the pathogenesis of HIV-associated renal disease. Host factors may modify disease expression at the level of cytokine networks and the renal microvasculature and contribute to the pathogenic effects of HIV-1 infection on the kidney.

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.

Does Haart Improve Renal Function? An Association between Serum Cystatin C Concentration, HIV Viral Load and Haart Duration

Aim

The prevalence of renal disease in human HIV-infected individuals varies between 2% and 10%. Many reports have demonstrated the beneficial effect of anti-retroviral (ARV) therapy on slowing the progression of renal diseases. The aim of our cross-sectional study was to determine serum cystatin C concentration in different stages of HIV infection and the relationship between cystatin C concentration and ARV treatment.

Methods

Cystatin C concentration was measured in the sera of 77 HIV-1-infected individuals and 18 HIV-seronegative volunteers. The glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease Study formula.

Results

HIV infection resulted in a significant increase in serum cystatin C concentration compared with healthy individuals (933.4±32.1 vs 621.1 ±56.8 ng/ml, P<0.001). There were no significant differences in urea, creatinine and GFR between those groups. On multivariate analyses serum cystatin C was independently associated with highly active antiretroviral therapy (HAART) duration (β=-0.34, P=0.04) and HIV viral load (β=0.33, P=0.04), whereas there were no significant relationships with age, body mass index, HIV duration, CD4+ and CD8+ T-cell counts and serum high sensitivity C-reactive protein concentration.

Conclusions

Our initial observations indicate that serum cystatin C, which may reflect mild renal dysfunction, is increased during HIV-infection and is associated with HIV viral load. Long-lasting HAART seems to decrease cystatin C concentration, thus potentially improves renal function.

HIV-associated nephropathy

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is one of the most important causes of progressive kidney failure in HIV-1-seropositive patients. Since the 1980s, much has been published regarding the epidemiology, pathogenesis, and treatment of HIVAN. Our knowledge of the clinical features, pathologic manifestations, course, and potential outcome of HIVAN has increased considerably. The use of highly active antiretroviral therapy has shown significant improvement in the outcome of human immunodeficiency virus infection and is found to be effective in preventing end-stage renal disease. The purpose of this review is to summarize the data about the clinical manifestations, pathogenesis and pathophysiologic mechanisms of HIVAN with particular attention on treatment including pharmaceutical and renal replacement options.

HIV-1 infection initiates an inflammatory cascade in human renal tubular epithelial cells

HIV-associated nephropathy (HIVAN) is the most common cause of chronic renal failure in HIV-infected patients. Tubulointerstitial inflammation is a prominent component of the histopathology of HIVAN. The pathogenesis of HIVAN is a result of infection of renal epithelial cells, but the cellular response to this infection remains poorly defined. In these studies, we used oligonucleotide microarrays to identify differentially expressed genes in renal tubular epithelial cells from a patient with HIVAN at three time points after infection with vesicular stomatitis virus-pseudotyped gag/pol-deleted HIV-1. Very few genes were differentially expressed 12 and 24 hours after infection. Three days after infection, however, 47 genes were upregulated by at least 1.8-fold. The most prominent response of these cells to HIV-1 expression was production of proinflammatory mediators, including chemokines, cytokines, and adhesion molecules. Many of the upregulated genes are targets of interleukin 6 and nuclear factor kappa B regulation, suggesting a central role for these proteins in the response of tubular epithelial cells to HIV-1 infection. Analysis of kidneys from HIV-1 transgenic mice revealed upregulation of many of the proinflammatory genes identified in the microarray studies. These studies provide novel insights into the mechanisms by which HIV-1 infection of tubular epithelial cells leads to tubulointerstitial inflammation and progressive renal injury.

HIV-Associated Renal Diseases and Highly Active Antiretroviral Therapy--Induced Nephropathy

Renal disease is becoming an increasingly prevalent entity in human immunodeficiency virus (HIV)-infected patients; it occurs in a variety of clinical settings and is associated with histopathological changes. HIV-related renal impairment can present as acute or chronic kidney disease; it can be caused directly or indirectly by HIV and/or by drug-related effects that are directly nephrotoxic or lead to changes in renal function by inducing metabolic vaculopathy and renal damage. Acute renal failure is frequently caused by the toxic effects of antiretroviral therapy or nephrotoxic antimicrobial substances used in the treatment of opportunistic infections. Chronic renal disease can be caused by multiple pathophysiological mechanisms, leading to HIV-associated nephropathy, a form of collapsing focal glomerulosclerosis, thrombotic microangiopathy, and various forms of immune complex glomerulonephritis. The increase in life expectancy and alteration of lipid metabolism due to receipt of highly active antiretroviral therapy are expected to result in an increased prevalence of diabetes and hypertension and, thus, to secondary diabetic and hypertensive renal damage. Antiretroviral agents, such as indinavir and tenofovir, have been associated with nephrotoxic drug effects that have been shown to be reversible in most cases. In this article, we review the current knowledge about acute and chronic HIV-associated renal disease, metabolic alterations and related nephropathies, and toxic drug effects of combination antiretroviral pharmacotherapy.

Human Immunodeficiency Virus-associated Nephropathy

Human immunodeficiency virus-associated nephropathy (HIVAN) is characterized by high-grade proteinuria and rapid progression to end-stage renal disease (ESRD). Despite the large numbers of HIV-infected cases in Asian countries, data on HIVAN in this area are limited. We report a 54-year-old Taiwanese man with HIVAN who presented with cytomegalovirus retinitis, renal insufficiency (serum creatinine, 3.8 mg/dL) and nephrotic range proteinuria with a daily protein loss of 10.8 g. Despite highly active antiretroviral therapy (HAART) for 31 months, renal failure developed requiring maintenance hemodialysis. Renal biopsy showed collapsing focal segmental glomerular sclerosis, podocyte proliferation and tubulointerstitial nephritis with mononuclear cell infiltration. These features were compatible with HIVAN. Although hemodialysis was instituted, he died 2 months later due to nosocomial pneumonia complicated with multiple organ failure. In summary, this case of HIVAN in a Taiwanese patient shows that the condition may progress to ESRD despite successful viral suppression with HAART.

Pharmacotherapy for human immunodeficiency virus-associated nephropathy

Approximately 10% of adult patients with human immunodeficiency virus (HIV) infection have HIV-associated nephropathy (HIVAN). This condition, a leading cause of renal failure, is characterized by damage to specific areas of the renal filtration system. It manifests with increased serum creatinine levels, overt proteinuria, and in some patients, end-stage renal disease (ESRD). The mortality rate for HIVAN-related ESRD is high-30% within the first year of onset. Most instances of HIVAN occur in patients of African descent. Although advances in defining the pathology have been made, the optimal treatment strategy remains unclear. Potential benefits of potent combination antiretroviral therapy, angiotensin-converting enzyme (ACE) inhibitors, and corticosteroids have been reported in small clinical trials and case reports. Cyclosporine is another option, but clinical experience with this agent in managing HIVAN is limited. Few conclusions can be drawn from the limited body of available evidence. Antiretroviral therapy, ACE inhibitors, and corticosteroids are possibly associated with reversal of serum creatinine level increases and proteinuria, but studies are necessary to further define the role of these agents in therapy. Close monitoring is advised when treating any patient with HIVAN.

Nephrotic range proteinuria and CD4 count as noninvasive indicators of HIV-associated nephropathy

PURPOSE

Human immunodeficiency virus (HIV)-associated nephropathy is a common and serious cause of progressive renal insufficiency in patients with HIV, frequently presenting with nephrotic range proteinuria. The purpose of this study is to document the histopathologic diagnoses seen in HIV-positive patients with and without nephrotic range proteinuria and to evaluate the predictive value of both nephrotic range proteinuria and CD4 count in diagnosing HIV-associated nephropathy.

METHODS

We performed a cross-sectional, single-center study of all 107 HIV-positive patients who had both a renal biopsy and urine protein measurement between 1995 and 2002. Nephrotic range proteinuria was defined as a urine protein-to-creatinine ratio > 3 or a 24-hour urine protein > 3 g. Clinical and laboratory characteristics of those patients with and without HIV-associated nephropathy were compared. Sensitivity, specificity, and positive and negative predictive values of nephrotic range proteinuria in the diagnosis of HIV-associated nephropathy were determined.

RESULTS

Fifty-five biopsied patients had nephrotic range proteinuria, among whom 29 (53%) were diagnosed with HIV-associated nephropathy. Among the remaining patients, 12 had non-HIV-associated nephropathy focal segmental glomeruloscerlosis, 3 had membranoproliferative glomerulonephritis, 2 had AA Amyloid, 2 had diabetic nephropathy, and 7 had other diagnoses. Sensitivity, specificity, and positive and negative predictive values of nephrotic proteinuria in the diagnosis of HIV-associated nephropathy were 73%, 61%, 53%, and 79%, respectively. The patients with HIV-associated nephropathy had a significantly higher creatinine (8.2 mg/dL vs 2.5 mg/dL, P < .001) and a lower CD4 count (158 count/mm3 vs 349 count/mm3, P < .01) at the time of biopsy. Although significantly more patients with HIV-associated nephropathy had a CD4 count below 200 (P = .03), among those with a CD4 count below 200, 10 of 30 patients (33%) had diagnoses other than HIV-associated nephropathy. Injection drug use, presence of hepatitis C, and hypertension were not associated with HIV-associated nephropathy.

CONCLUSION

Our results suggest that HIV patients with nephrotic range proteinuria warrant a kidney biopsy because the presence of nephrotic range proteinuria, even in the presence a low CD4 count, does not establish the diagnosis of HIV-associated nephropathy.

Highly active antiretroviral therapy and the kidney: an update on antiretroviral medications for nephrologists

Highly active antiretroviral therapy has dramatically altered the treatment and life expectancy of individuals who are infected with HIV. More than 20 antiretroviral drugs and drug combinations now are available in the United States. Nephrologists need to have an understanding of the pharmacokinetics of antiretroviral medications and the proper dosing of these medications in patients with impaired kidney function. It is also important for nephrologists to be aware of drug-drug interactions that can occur between antiretroviral medications and other medications that they may prescribe, including immunosuppressive medications that are used for renal transplantation, as this becomes more common in HIV-infected patients. Adverse reactions that affect the kidneys and cause fluid-electrolyte complications occur with certain antiretroviral agents, although most are relatively free of nephrotoxicity. This article reviews the clinical pharmacology and dosing modifications of the newer antiretroviral medications in patients with reduced kidney function; important drug-drug interactions involving these medications, particularly with other medications that are likely to be prescribed by nephrologists; and renal toxicities of antiretroviral agents.

HIV-associated renal disorders: recent insights into pathogenesis and treatment

Renal electrolyte disorders, acute renal failure, and a variety of chronic renal diseases are common in HIV-infected patients. Glomerular disorders include IgA nephropathy, cryoglobulinemia, amyloidosis, and a lupus-like immune complex glomerulopathy. The most attention has been focused on collapsing glomerulopathy associated with nephrotic syndrome and progressive renal failure, which appears to be unique for patients with HIV/AIDS, called HIV-associated nephropathy (HIVAN), and it occurs predominantly in African American patients. Investigations in humans and in a transgenic mouse model reveal direct infection of renal epithelial cells by HIV and toxic cellular and immunologic processes mediated by HIV glycoproteins as the principal pathophysiology of HIVAN. Highly active antiretroviral treatment may be associated with an improved renal outcome and even reversal of kidney disease in some patients. Treatment with angiotensin-converting enzyme inhibitors may avert progression of HIVAN to end-stage kidney disease and result in superior patient and kidney survival as compared with untreated patients.

Highly active antiretroviral therapy and the epidemic of HIV+ end-stage renal disease

The rise in the number of patients with HIV-associated nephropathy and HIV-infection with end-stage renal disease (HIV+ ESRD) continues to be a substantial concern for the ESRD program. In order to assess the impact of highly active antiretroviral therapy (HAART) on the progression of patients with AIDS to the development of ESRD and to project the prevalence of HIV+ ESRD through 2020, a mathematical model of the dynamics of HIV+ infection in the ESRD population was developed. Epidemiologic data on AIDS and HIV+ ESRD among black individuals in the United States were obtained since 1991 from the Centers for Disease Control and Prevention and US Renal Data System, respectively. The model was constructed to predict the prevalence of HIV+ ESRD incorporating the current rate of growth in AIDS prevalence. Two possible trends were considered: linear AIDS growth and exponential AIDS growth. The likely effectiveness of HAART in slowing progression to HIV+ ESRD was estimated from the best fit of the model to the data after 1995, when HAART was introduced. The model was then used to evaluate recent data and to project the prevalence of HIV+ ESRD through 2020. The model suggested that HAART has reduced the rate of progression from AIDS to HIV+ ESRD by 38%. The model projected an increase in HIV+ ESRD prevalence in the future as a result of the increase in the AIDS population among black individuals. This increase was predicted even assuming a 95% reduction in the progression from AIDS to HIV+ ESRD. Despite the potential benefit of HAART, the prevalence of HIV+ ESRD in the United States is expected to rise in the future as a result of the expansion of the AIDS population among black individuals. It is concluded that prevention of progression to ESRD should focus on early antiretroviral treatment of HIV-infected patients who have evidence of HIV-associated nephropathy.