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

An Update on Viral Infection-Associated Collapsing Glomerulopathy

The COVID-19 era has been a reminder to clinicians around the world of the important role that viral infections play in promoting glomerular disease. Several viral infections including human immunodeficiency virus (HIV), severe acute respiratory syndrome coronavirus 2, Epstein-Barr virus, cytomegalovirus, and parvovirus B19 can cause podocyte injury and present with a collapsing glomerulopathy (CG) variant of focal segmental glomerulosclerosis or minimal change disease. CG associated with COVID-19 has been termed COVID-19-associated nephropathy due to its striking resemblance to HIV-associated nephropathy. Host susceptibility is a major determinant of viral infection-associated CG, and the presence of two APOL1 risk variants explains most of the racial predilection to viral-associated CG observed in individuals of African ancestry. Interactions between APOL1 risk variants, viral genes, and the systemic inflammatory response to viral infection all contribute to kidney injury. This review will summarize our current knowledge of viral infection-associated CG, focusing primarily on the clinical presentation, histological features, mechanisms, and disease course of HIV-associated nephropathy and COVID-19-associated nephropathy.

Chronic kidney disease and its predictors among highly active antiretroviral therapy naïve and experienced HIV-infected individuals at the selected hospitals, Southwest Ethiopia: a comparative cross-sectional study

Objective

This study aimed to determine the prevalence of chronic kidney disease (CKD) and its predictors among highly active antiretroviral therapy (HAART) naïve and experienced HIV-infected individuals.

Method and analysis

Hospital-based comparative cross-sectional study design was used at Mizan-Tepi University Teaching Hospital, Bonga General Hospital and Tepi General Hospital. A total of 616 naïve and experienced HIV-infected individuals participated. A systematic random sampling and consecutive sampling methods were applied to select the HAART experienced and naïve HIV-infected individuals, respectively. Descriptive statistics were used for all study variables. Independent t-test and logistic regression analysis were performed to compare the mean between naïve and experienced patients and to identify its predictor variables considering a <0.05 and 95% CI, respectively.

Results

A total of 616 HIV-positive respondents were enrolled in this study. The prevalence of CKD was 41 (29.3%) of 140 and 78 (16.4%) of 476 HAART-naïve and HAART-experienced HIV patients, respectively. Rural residency, being anaemic, being hypertensive, having had a family history of kidney disease and stage IV current WHO) clinical stage were independent risk factors of CKD among naïve HIV patients, whereas, rural residency, utilisation of drinking water per day below the recommended amount, being anaemic, being hypertensive, stage IV current WHO clinical stage and obesity were predictors of CKD among experienced HIV patients. Statistically significant difference was observed between HAART naïve and HAART experienced participants with regard to the mean glomerular filtration rate level (t=-3.987, 95% CI -18.29 to -6.22).

Conclusion

CKD was higher among HAART-naïve than HAART-experienced study participants. Therefore, early initiation of antiretroviral therapy (ART) drugs, modification of lifestyles to decrease obesity and early detection and treatment of comorbidities such as anaemia and hypertension may have profound effects in reducing CKD and increasing patients' quality of life.

FSGS and COVID-19 in Non-African American Patients

Collapsing Focal Segmental Glomerulosclerosis (FSGS) has been reported relatively frequently in African American (AA) patients with coronavirus disease 2019 (COVID-19), and it is associated almost always with Apolipoprotein L gen 1 (APOL1) high-risk variants. We reviewed the published literature from April 2020 to November 2022 searching for non-African American (non-AA) patients with FSGS associated with COVID-19 (eight White patients, six Hispanic patients, three Asian patients, one Indian patient, and one Asian Indian patient). The following histologic patterns were found: collapsing (n=11), not otherwise specified (n=5), tip (n=2), and perihilar (n=1). Fifteen of the 19 patients had AKI. The APOL1 genotype was reported in only six of the 19 non-AA patients. Three of them (two Hispanic patients and one White patient) with collapsing FSGS had high-risk APOL1 variants. The other three patients (two White patients and one Hispanic patient with the collapsing variant, tip variant, and not otherwise specified) had low-risk APOL1 variants. Among 53 African American patients with collapsing FSGS associated with COVID-19, 48 had high-risk APOL1 variants and five had low-risk APOL1 variants. We conclude that in non-AA patients, FSGS is a rare complication of COVID-19. FSGS associated with COVID-19 can occur rarely with low-risk APOL1 variants in non-AA and AA patients. Non-AA patients reported to be associated with high-risk APOL1 variants possibly reflect inaccuracy of self-reported race with AA admixture because of unknown ancestry. Given the importance of APOL1 in the pathogenesis of FSGS associated with viral infection and to avoid racial bias, it seems appropriate that APOL1 testing be considered in patients with FSGS associated with COVID-19, regardless of self-reported race.

Treatment of HIV-Associated Lupus-like Membranous Nephropathy with Tacrolimus: A Case Report and Review of the Literature

Renal complications of HIV infection are common and histologically diverse. Besides HIV-associated nephropathy, which is the most well-defined glomerular disorder, immune-complex-mediated glomerulonephritis (HIVICK) is also encountered in the setting of HIV infection and may occasionally present with “lupus-like” features by light microscopy and immunofluorescence. Management of HIVICK remains controversial and mainly focuses on HIV viremia suppression with combined antiretroviral therapy. Immunosuppressive therapy may be used in order to mitigate the renal inflammation induced by the immune complex deposition. Data regarding the use of immunosuppressants in HIVICK are very limited, mostly including corticosteroids and mycophenolate acid analogues. Herein, we present the case of a 40-year-old HIV-infected Caucasian man with nephrotic syndrome, renal impairment, and a “lupus-like” membranous pattern in the kidney biopsy, who achieved a partial response of his proteinuria with a tacrolimus-based regimen in combination with antiretroviral therapy.

Viral Glomerulopathy

Background

The association between viral infections and glomerular diseases, commonly known as "viral glomerulopathies," has been described in various clinical scenarios for decades. Despite advancements in diagnostic tools, it remains challenging to establish a causative link fully.

Summary

Data from mouse models have substantiated clinical observations and implicate direct viral infection in the pathogenesis of viral glomerulopathy, particularly in human immunodeficiency virus-associated nephropathy. In addition to the traditional concept of direct viral effects on kidneys, other factors such as APOL1 risk alleles can further modify the clinical outcomes or presentations of different viral glomerulopathies. Newly developed antiviral drugs are now applicable to a wider range of patients with lower kidney function and fewer side effects.

Key Message

Efforts focusing on vaccines and antiviral treatments have significantly reduced the incidence of viral glomerulopathies. However, the most recent pandemic caused by severe acute respiratory syndrome coronavirus 2 infection complicated by COVID-associated nephropathy illustrates our susceptibility to novel viruses. Ongoing research is pivotal to deciphering the mechanisms behind viral glomerulopathies and discovering therapeutics in a collaborative approach.

Renal function and associated mortality risk in adults commencing HIV antiretroviral therapy in Zimbabwe

BACKGROUND

People with HIV (PWH) in sub-Saharan Africa appear to have a higher incidence of renal disease than other global regions but data are limited. This renal impairment may be associated with an increased mortality risk.

AIMS

To define the prevalence of renal disease and explore its association with mortality risk in a cohort from Zimbabwe commencing antiretroviral therapy (ART) for HIV infection.

METHODS

A retrospective study of all patients aged at least 18 years, commenced on ART for HIV infection at the Newlands Clinic in Harare, Zimbabwe between January 2007 and September 2019 was conducted. Data were extracted from electronic medical records. Patients with no baseline creatinine measurement were excluded. Baseline characteristics were assessed as potential predictors for mortality by Cox proportional hazard regression.

RESULTS

Three thousand and thirty-nine patients were eligible for inclusion. Most were female (62.1%), with a median age of 36 years (IQR 30-43). At baseline, 7.3% had an estimated glomerular filtration rate (eGFR) 90 ml/min per 1.73 m2 or less and 11.4% had proteinuria. Over a median follow-up period of 4.6 years (IQR 2.5-6.9), the mortality rate was 8.7%. One half of deaths (49.2%) occurred within the first year. In multivariable analysis, a baseline eGFR between 60 and 90 ml/min per 1.73 m2 [hazard ratio 2.22, 95% confidence interval (CI) 1.46-3.33, P < 0.001] and proteinuria (hazard ratio 2.10, 95% CI 1.35-3.27, P < 0.001) were associated with increased mortality risk.

CONCLUSION

Baseline renal impairment was common. Both a reduced eGFR or proteinuria were independently associated with a doubling of mortality risk. These should serve as markers in the clinical setting of at-risk patients.

Genetic Variants of APOL1 Are Major Determinants of Kidney Failure in People of African Ancestry With HIV

Introduction

Variants of the APOL1 gene are associated with chronic kidney disease (CKD) in people of African ancestry, although evidence for their impact in people with HIV are sparse.

Methods

We conducted a cross-sectional study investigating the association between APOL1 renal risk alleles and kidney disease in people of African ancestry with HIV in the UK. The primary outcome was end-stage kidney disease (ESKD; estimated glomerular filtration rate [eGFR] of <15 ml/min per 1.73 m2, chronic dialysis, or having received a kidney transplant). The secondary outcomes included renal impairment (eGFR <60 ml/min per 1.73 m2), albuminuria (albumin-to-creatinine ratio [ACR] >30 mg/mmol), and biopsy-proven HIV-associated nephropathy (HIVAN). Multivariable logistic regression was used to estimate the associations between APOL1 high-risk genotypes (G1/G1, G1/G2, G2/G2) and kidney disease outcomes.

Results

A total of 2864 participants (mean age 48.1 [SD 10.3], 57.3% female) were genotyped, of whom, 354 (12.4%) had APOL1 high-risk genotypes, and 99 (3.5%) had ESKD. After adjusting for demographic, HIV, and renal risk factors, individuals with APOL1 high-risk genotypes were at increased odds of ESKD (odds ratio [OR] 10.58, 95% CI 6.22-17.99), renal impairment (OR 5.50, 95% CI 3.81-7.95), albuminuria (OR 3.34, 95% CI 2.00-5.56), and HIVAN (OR 30.16, 95% CI 12.48-72.88). An estimated 49% of ESKD was attributable to APOL1 high-risk genotypes.

Conclusion

APOL1 high-risk genotypes were strongly associated with kidney disease in people of African ancestry with HIV and accounted for approximately half of ESKD cases in this cohort.

Impact of Antiretroviral Therapy on Kidney Disease in HIV Infected Individuals - A Qualitative Systematic Review

Kidney disease is the fourth most common cause of non-AIDS-related mortality in people living with HIV. Combination antiretroviral therapy (cART) remains the cornerstone of treatment. However, little is known about the impact of cART on disease outcomes in patients with HIV-associated nephropathy (HIVAN) and HIV-immune complex kidney disease (HIVICK). This systematic review evaluates the impact of cART on progression to end-stage kidney disease (ESKD) and other outcomes in HIV-infected individuals. We conducted a literature search utilizing PubMed, and Cochrane database and 11 articles met inclusion criteria for analysis of which nine HIVAN studies showed decreased progression to ESKD or death for subjects when treated with cART versus those untreated. However, two studies showed no survival advantage with cART. Three HIVICK studies showed improvement in delaying ESKD in subjects on cART compared to untreated subjects. cART appeared to reduce the risk to ESKD or death in patients with both HIVAN and HIVICK.

Systematic analysis of safety profile for darunavir and its boosted agents using data mining in the FDA Adverse Event Reporting System database

This current investigation was aimed to generate signals for adverse events (AEs) of darunavir-containing agents by data mining using the US Food and Drug Administration Adverse Event Reporting System (FAERS). All AE reports for darunavir, darunavir/ritonavir, or darunavir/cobicistat between July 2006 and December 2019 were identified. The reporting Odds Ratio (ROR), proportional reporting ratio (PRR), and Bayesian confidence propagation neural network (BCPNN) were used to detect the risk signals. A suspicious signal was generated only if the results of the three algorithms were all positive. A total of 10,756 reports were identified commonly observed in hepatobiliary, endocrine, cardiovascular, musculoskeletal, gastrointestinal, metabolic, and nutrition system. 40 suspicious signals were generated, and therein 20 signals were not included in the label. Severe high signals (i.e. progressive extraocular muscle paralysis, acute pancreatitis, exfoliative dermatitis, acquired lipodystrophy and mitochondrial toxicity) were identified. In pregnant women, umbilical cord abnormality, fetal growth restriction, low birth weight, stillbirth, premature rupture of membranes, premature birth and spontaneous abortion showed positive signals. Darunavir and its boosted agents induced AEs in various organs/tissues, and were shown to be possibly associated with multiple adverse pregnant conditions. This study highlighted some novel and severe AEs of darunavir which need to be monitored prospectively.

Pharmacotherapeutic options for kidney disease in HIV positive patients

INTRODUCTION

Since the developmentof combined antiretroviral therapy (cART), HIV-associated mortality and the incidence of HIV-associated end-stage kidney disease (ESKD) has decreased. However, in the United States, an increase in non-HIV-associated kidney diseases within the HIV-positive population is expected.

AREAS COVERED

In this review, the authors highlight the risk factors for kidney disease within an HIV-positive population and provide the current recommendations for risk stratification and for the monitoring of its progression to chronic kidney disease (CKD), as well as, treatment. The article is based on literature searches using PubMed, Medline and SCOPUS.

EXPERT OPINION

The authors recommend clinicians (1) be aware of early cART initiation to prevent and treat HIV-associated kidney diseases, (2) be aware of cART side effects and discriminate those that may become more nephrotoxic than others and require dose-adjustment in the setting of eGFR ≤ 30ml/min/1.73m², (3) follow KDIGO guidelines regarding screening and monitoring for CKD with a multidisciplinary team of health professionals, (4) manage other co-infections and comorbidities, (5) consider changing cART if drug induced toxicity is established with apparent eGFR decline of ≥ 10ml/min/1.73m² or rising creatinine (≥0.5mg/dl) during drug-drug interactions, and (6) strongly consider kidney transplant in appropriately selected individuals with end stage kidney failure.

Clinical characteristics and outcome of HIV infected patients with chronic kidney disease in Sub Saharan Africa: an example from in Cameroon

BACKGROUND

Chronic kidney disease (CKD) is one of the major complications of Human immune deficiency Virus (HIV) and a risk factor for poor outcome of these patients. We aimed to describe the profile and outcome of HIV positive patients with CKD in Douala general hospital in Cameroon.

METHODS

HIV positive patients with CKD referred to the nephrologist from January 2007 to March 2013 were included. Socio demographic, clinical (history and stage of HIV, comorbidities, baseline nephropathy, used of c-ART), para clinical data at referral (serum urea, creatinine, full blood count, CD4 count, serum calcium, phosphorus, albumin), dialysis initiation and outcome at 1 year were collected from medical records. GFR was estimated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. CKD was defined and classified according to the Kidney Disease Improving Global Outcomes (KDIGO 2012).

RESULTS

We included 156 patients (51.3% men) with a mean age of 45.4 ± 12.1 years. Hypertension (36.5%), diabetes (17.9%) and Hepatitis C (7.7%) were the main comorbidities. HIV associated nephropathy (27.6%), chronic glomerulonephritis (15.4%) diabetes (14.1%) and hypertension (13.5%) were the leading causes of kidney disease. Before referral HIV status was known by 109 (69.9%) patients, with 76 (69.7%) being on c-ART. Median CD4 count was 241 (117-438) cells/mm3. Prevalence of anemia (93.9%), hypocalcemia (68.6%) and Proteinuria (77.6%) was high, 94 (60.3%) patients were at CKD stage 5 at referral and 37 (23.7%) underwent emergency dialysis. After 1 year, 64 (41.0%) patients were lost to follow up. The mortality rate was 49% and 25 (28.7%) were maintenance hemodialysis, and being on c-ART was associated with a lower risk of death (HR: 0.45; 95% CI: 0.23-0.89; p = 0.021).

CONCLUSION

HIV patients with CKD were referred late with high morbidity and need for urgent hemodialysis. HIVAN was the main etiology of CKD and mortality rate was high mainly due to the absence of c-ART at referral.

Optimal management of HIV- positive adults at risk for kidney disease in Nigeria (Renal Risk Reduction "R3" Trial): protocol and study design

Background

Individuals with two copies of the apolipoprotein-1 (APOL1) gene risk variants are at high risk (HR) for non-diabetic kidney disease. The presence of these risk variants is highest in West Africa, specifically in Nigeria. However, there is limited availability of dialysis and kidney transplantation in Nigeria, and most individuals will die soon after developing end-stage renal disease. Blocking the renin angiotensin aldosterone system with angiotensin-converting enzyme inhibitors (ACEi) is a well-recognized strategy to slow renal disease progression in patients with diabetes mellitus with chronic kidney disease (CKD) and in patients with HIV-associated nephropathy. We propose to determine whether presence of the APOL1 HR genotype alters or predicts responsiveness to conventional therapy to treat or prevent CKD and if addition of an ACEi to standard combination antiretroviral therapy (ART) reduces the risk of kidney complications among non-diabetic Nigerian adults.

Methods/design

We will screen 2600 HIV-positive adults who have received ART to (1) determine the prevalence of APOL1 risk variants and assess whether APOL1 HR status correlates with prevalent albuminuria, estimated glomerular filtration rate (eGFR), and/or prevalent CKD; (2) assess, via a randomized, placebo-controlled trial (RCT) in a subset of these participants with microalbuminura (n = 280) whether addition of the ACEi, lisinopril, compared to standard of care, significantly reduces the incidence or progression of albuminuria; and (3) determine whether the APOL1 HR genotype is associated with worse kidney outcomes (i.e. eGFR slope or regression of albuminuria) among participants in the RCT.

Conclusions

This study will examine the increasing prevalence of kidney diseases in HIV-positive adults in a West African population, and the relationship between these diseases and the APOL1 high-risk genotype. By evaluating the addition of an ACEi to the care of individuals with HIV infection who have albuminuria, our trial will provide definitive evidence to guide strategies for management and clinical care in this population, with the goal of reducing HIV-related kidney complications.

Trial registration

ClinicalTrials.gov, NCT03201939. Registered on 26 August 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3436-y) contains supplementary material, which is available to authorized users.

APOL1 polymorphisms and kidney disease: loss-of-function or gain-of-function?

The mechanism that explains the association of APOL1 variants with nondiabetic kidney diseases in African Americans remains unclear. Kidney disease risk is inherited as a recessive trait, and many studies investigating the intracellular function of APOL1 have indicated the APOL1 variants G1 and G2 are associated with cytotoxicity. Whether cytotoxicity results from the absence of a protective effect conferred by the G0 allele or is induced by a deleterious effect of variant allele expression has not be conclusively established. A central issue hampering basic biology studies is the lack of model systems that authentically replicate APOL1 expression patterns. APOL1 is present in humans and a few other primates and appears to have important functions in the kidney, as the kidney is the primary target for disease associated with the genetic variance. There have been no studies to date assessing the function of untagged APOL1 protein under native expression in human or primate kidney cells, and no studies have examined the heterozygous state, a disease-free condition in humans. A second major issue is the chronic kidney disease (CKD)-associated APOL1 variants are conditional mutations, where the disease-inducing function is only evident under the appropriate environmental stimulus. In addition, it is possible there may be more than one mechanism of pathogenesis that is dependent on the nature of the stressor or other genetic variabilities. Studies addressing the function of APOL1 and how the CKD-associated APOL1 variants cause kidney disease are challenging and remain to be fully investigated under conditions that faithfully model known human genetics and physiology.

Autoimmune Kidney Diseases Associated with Chronic Viral Infections

Autoimmune kidney diseases triggered by viruses are an important cause of kidney disease in patients affected by chronic viral infection. Hepatitis B virus (HBV) infection is associated with membranous nephropathy and polyarteritis nodosa. Hepatitis C virus (HCV) infection is a major cause of cryoglobulinemic glomerulonephritis. Patients with human immunodeficiency virus (HIV) may develop HIV-associated nephropathy, a form of collapsing focal segmental glomerulosclerosis, or various forms of immune-complex-mediated kidney diseases. This article summarizes what is known about the pathogenesis, diagnosis, and management of immune-mediated kidney diseases in adults with chronic HBV, HCV, and HIV infections.

HIV-associated nephropathy: links, risks and management

Despite the decreased incidence of human immunodeficiency virus (HIV)-associated nephropathy due to the widespread use of combined active antiretroviral therapy, it remains one of the leading causes of end-stage renal disease (ESRD) in HIV-1 seropositive patients. Patients usually present with low CD4 count, high viral load and heavy proteinuria, with the pathologic findings of collapsing focal segmental glomerulosclerosis. Increased susceptibility exists in individuals with African descent, largely due to polymorphism in APOL1 gene. Other clinical risk factors include high viral load and low CD4 count. Advanced kidney disease and nephrotic range proteinuria have been associated with progression to ESRD. Improvement in kidney function has been observed after initiation of combined active antiretroviral therapy. Other treatment options, when clinically indicated, are inhibition of the renin-angiotensin system and corticosteroids. Further routine management approaches for patients with chronic kidney disease should be implemented. In patients with progression to ESRD, kidney transplant should be pursued, provided that viral load control is adequate. Screening for the presence of kidney disease upon detection of HIV-1 seropositivity in high-risk populations is recommended.

Management of drug-resistant tuberculosis in special sub-populations including those with HIV co-infection, pregnancy, diabetes, organ-specific dysfunction, and in the critically ill

Tuberculosis remains a major problem globally, and is the leading cause of death from an infectious agent. Drug-resistant tuberculosis threatens to marginalise the substantial gains that have recently been made in the fight against tuberculosis. Drug-resistant TB has significant associated morbidity and a high mortality, with only half of all multidrug-resistant TB patients achieving a successful treatment outcome. Patients with drug-resistant TB in resource-poor settings are now gaining access to newer and repurposed anti-tuberculosis drugs such as bedaquiline, delamanid and linezolid. However, with ever increasing rates of co-morbidity, there is little guidance on how to manage complex patients with drug-resistant TB. We address that knowledge gap, and outline principles underpinning the management of drug-resistant TB in special situations including HIV co-infection, pregnancy, renal disease, liver disease, diabetes, and in the critically ill.

Pharmacotherapy and treatment options for HIV-associated nephropathy

INTRODUCTION

Human immunodeficiency virus (HIV) remains a worldwide disease with significant mortality and morbidity. There are a multitude of HIV-related kidney diseases including HIV-associated nephropathy (HIVAN) most prominently. The risk of developing HIVAN increases with decreasing CD4 count, higher viral load, and based on genetic factors. The mortality rate for those with HIVAN-end stage renal disease (ESRD) remains 2.5-3 times higher than ESRD patients without HIVAN.

AREAS COVERED

The epidemiology of HIVAN, particularly risk assessment, will be explored in this review. Further, the pathogenesis of HIVAN, from viral-specific renal expression to the role of genetics as well as characteristic renal pathology will be described. Diagnosis and management of HIVAN will be addressed, with an emphasis on various treatment strategies including medication, dialysis, and kidney transplantation.

EXPERT OPINION

HIVAN is associated with a high risk for progression to ESRD and increased mortality. The backbone of HIVAN therapy remains combined anti-retroviral therapy (cART), while adjunctive therapies including RAAS blockade and prednisone, should be considered. In those who progress to ESRD, dialysis remains the mainstay of management, though increasing evidence has demonstrated that kidney transplantation can be effective in those with controlled HIV disease.

HIV and kidney diseases: 35 years of history and consequences

Kidney diseases in human immunodeficiency virus (HIV)-infected patients are often misdiagnosed. Despite reductions in morbidity and mortality owing to widespread use of highly effective combination antiretroviral therapy (cART), acute kidney injury (AKI) and chronic kidney disease (CKD) are still more common in these patients than in the general population, and are associated with poor health outcomes. HIV-associated nephropathy and HIV immune complex kidney diseases are the more recognizable HIV-related kidney diseases. However, a broad spectrum of kidney disorders related or not directly related with HIV infection can be observed, including cART-induced AKI, CKD, proximal tubular dysfunction, crystalluria and urolithiasis, among others. This review summarizes the major epidemiologic studies of kidney diseases in HIV-infected patients, discusses novel approaches that may potentially limit nephrotoxicity such as the use of tenofovir alafenamide, and outlines current screening measures for early diagnosis of kidney dysfunction or tubular damage, and for accurate detection of increased risk for acute or chronic kidney diseases.

HIV and chronic kidney disease

Chronic kidney disease (CKD) is a frequent complication of HIV infection, occurring in 3.5 - 48.5%, and occurs as a complication of HIV infection, other co-morbid disease and infections and as a consequence of therapy of HIV infection and its complications. The classic involvement of the kidney by HIV infection is HIV-associated nephropathy (HIVAN), occurring typically in young adults of African ancestry with advanced HIV disease in association with APOL1 high-risk variants. HIV-immune complex disease is the second most common diagnosis obtained from biopsies of patients with HIV-CKD. CKD is mediated by factors related to the virus, host genetic predisposition and environmental factors. The host response to HIV infection may influence disease phenotype through activation of cytokine pathways. With the introduction of antiretroviral therapy (ART), there has been a decline in the incidence of HIVAN, with an increasing prevalence of focal segmental glomerulosclerosis. Several studies have demonstrated the overall improvement in kidney function when initiating ART for HIV CKD. Progression to end stage kidney disease has been reported to be more likely when high grade proteinuria, severely reduced eGFR, hepatitis B and/C co-infection, diabetes mellitus, extensive glomerulosclerosis, and chronic interstitial fibrosis are present. Improved renal survival is associated with use of renin angiotensin system blockers and viral suppression. Many antiretroviral medications are partially or completely eliminated by the kidney and require dose adjustment in CKD. Certain drug classes, such as the protease inhibitors and the non-nucleoside reverse transcriptase inhibitors, are metabolized by the liver and do not require dose adjustment. HIV-infected patients requiring either hemo- or peritoneal dialysis, who are stable on ART, are achieving survival rates comparable to those of dialysis patients without HIV infection. Kidney transplantation has been performed successfully in HIV-infected patients; graft and patient survival appears to be similar to that of HIV-uninfected recipients. Early detection of kidney disease by implementation of screening on diagnosis of HIV infection and annual screening thereafter will have an impact on the burden of disease, together with access to ART to those who require it. Programs for prevention of HIV infection are essential to prevent this lethal disease.

Multiple facets of HIV-associated renal disease

HIV infection has a broad spectrum of renal manifestations. This study examined the clinical and histological manifestations of HIV-associated renal disease, and predictors of renal outcomes. Sixty-one (64% male, mean age 45 years) HIV patients were retrospectively evaluated. Clinical presentation and renal histopathology were assessed, as well as CD4 T-cell count and viral load. The predictive value of histological lesion, baseline CD4 cell count and viral load for end-stage renal disease (ESRD) or death were determined using the Cox regression model. The outcomes of chronic kidney disease (CKD) and ESRD or death were evaluated by baseline CD4 cell count. The percent distribution at initial clinical presentation was non-nephrotic proteinuria (54%), acute kidney injury (28%), nephrotic syndrome (23%), and chronic kidney disease (22%). Focal segmental glomerulosclerosis (28%), mainly the collapsing form (HIVAN), acute interstitial nephritis (AIN) (26%), and immune complex-mediated glomerulonephritis (ICGN) (25%) were the predominant renal histology. Baseline CD4 cell count ≥ 200 cells/mm3 was a protective factor against CKD (hazard ratio=0.997; 95%CI=0.994-0.999; P=0.012). At last follow-up, 64% of patients with baseline CD4 ≥ 200 cells/mm3 had eGFR >60 mL·min-1·(1.73 m2)-1 compared to the other 35% of patients who presented with CD4 <200 cells/mm3 (log rank=9.043, P=0.003). In conclusion, the main histological lesion of HIV-associated renal disease was HIVAN, followed by AIN and ICGN. These findings reinforce the need to biopsy HIV patients with kidney impairment and/or proteinuria. Baseline CD4 cell count ≥ 200 cells/mm3 was associated with better renal function after 2 years of follow-up.

Clinical characteristics and outcomes of HIV-associated immune complex kidney disease

BACKGROUND

The pathogenesis and natural history of HIV-associated immune complex kidney disease (HIVICK) is not well understood. Key questions remain unanswered, including the role of HIV infection and replication in disease development and the efficacy of antiretroviral therapy (ART) in the prevention and treatment of disease.

METHODS

In this multicentre study, we describe the renal pathology of HIVICK and compare the clinical characteristics of patients with HIVICK with those with IgA nephropathy and HIV-associated nephropathy (HIVAN). Poisson regression models were used to identify risk factors for each of these pathologies.

RESULTS

Between 1998 and 2012, 65 patients were diagnosed with HIVICK, 27 with IgA nephropathy and 70 with HIVAN. Black ethnicity and HIV RNA were associated with HIVICK, receipt of ART with IgA nephropathy and black ethnicity and CD4 cell count with HIVAN. HIVICK was associated with lower rates of progression to end-stage kidney disease compared with HIVAN and IgA nephropathy (P < 0.0001). Patients with HIVICK who initiated ART and achieved suppression of HIV RNA experienced improvements in estimated glomerular filtration rate and proteinuria.

CONCLUSIONS

These findings suggest a pathogenic role for HIV replication in the development of HIVICK and that ART may improve kidney function in patients who have detectable HIV RNA at the time of HIVICK diagnosis. Our data also suggest that IgA nephropathy should be viewed as a separate entity and not included in the HIVICK spectrum.

African origins and chronic kidney disease susceptibility in the human immunodeficiency virus era

Chronic kidney disease (CKD) is a major public health problem worldwide with the estimated incidence growing by approximately 6% annually. There are striking ethnic differences in the prevalence of CKD such that, in the United States, African Americans have the highest prevalence of CKD, four times the incidence of end stage renal disease when compared to Americans of European ancestry suggestive of genetic predisposition. Diabetes mellitus, hypertension and human immunodeficiency virus (HIV) infection are the major causes of CKD. HIV-associated nephropathy (HIVAN) is an irreversible form of CKD with considerable morbidity and mortality and is present predominantly in people of African ancestry. The APOL1 G1 and G2 alleles were more strongly associated with the risk for CKD than the previously examined MYH9 E1 risk haplotype in individuals of African ancestry. A strong association was reported in HIVAN, suggesting that 50% of African Americans with two APOL1 risk alleles, if untreated, would develop HIVAN. However these two variants are not enough to cause disease. The prevailing belief is that modifying factors or second hits (including genetic hits) underlie the pathogenesis of kidney disease. This work reviews the history of genetic susceptibility of CKD and outlines current theories regarding the role for APOL1 in CKD in the HIV era.

HIV-associated nephropathies: epidemiology, pathology, mechanisms and treatment

HIV is a highly adaptive, rapidly evolving virus, which is associated with renal diseases including collapsing glomerulopathy-the classic histomorphological form of HIV-associated nephropathy. Other nephropathies related to viral factors include HIV-immune-complex kidney disease and thrombotic microangiopathy. The distribution of HIV-associated kidney diseases has changed over time and continues to vary across geographic regions worldwide. The reasons for this diversity are complex and include a critical role of APOL1 variants and possibly other genetic factors, disparities in access to effective antiviral therapies, and likely other factors that we do not yet fully understand. The mechanisms responsible for HIVAN, including HIV infection of podocytes and tubular epithelial cells, the molecules responsible for HIV entry, and diverse mechanisms of cell injury, have been the focus of much study. Although combined antiretroviral therapy is effective at preventing and reversing HIVAN, focal segmental glomerulosclerosis, arterionephrosclerosis and diabetic nephropathy are increasingly common in individuals who have received such therapy for many years. These diseases are associated with metabolic syndrome, obesity and premature ageing. Future directions for HIV-related kidney disease will involve regular screening for drug nephrotoxicity and incipient renal disease, as well as further research into the mechanisms by which chronic inflammation can lead to glomerular disease.

Hyperglycemia enhances kidney cell injury in HIVAN through down-regulation of vitamin D receptors

In the present study, we evaluated the effect of short term hyperglycemia on renal lesions in a mouse model (Tg26) of HIV-associated nephropathy (HIVAN). Control and Tg26 mice in groups (n=6) were administered either normal saline (FVBN or Tg) or streptozotocin (FVBN+STZ or Tg26+STZ). After two weeks, biomarkers were collected and kidneys were harvested. FVBN+ STZ and Tg26+STZ displayed elevated serum glucose levels when compared to FVBN and Tg26 respectively. Tg26+STZ displayed elevated (P<0.05) blood urea nitrogen (BUN) levels (P<0.05) and enhanced (P<0.01) proteinuria when compared to Tg26. Tg26+STZ displayed enhanced (P<0.001) number of sclerotic glomeruli and microcysts vs. Tg26. Renal tissues of Tg26 displayed down regulation of vitamin D receptor (VDR) expression and enhanced Ang II production when compared to FVBN mice. Hyperglycemia exacerbated down regulation of VDR and production of Ang II in FVBN and Tg mice. Hyperglycemia increased kidney cell reactive oxygen species (ROS) production and oxidative DNA damage in both FVBN and Tg26 mice. In in vitro studies, HIV down regulated podocyte VDR expression and also enhanced renin angiotensin system activation. In addition, both glucose and HIV stimulated kidney cell ROS generation and DNA damage and compromised DNA repair; however, tempol (superoxide dismutase mimetic), losartan (Ang II blocker) and EB1089 (VDR agonist) provided protection against DNA damaging effects of glucose and HIV. These findings indicated that glucose activated the RAS and inflicted oxidative stress-mediated DNA damage via down regulation of kidney cell VDR expression in HIV milieu both in vivo and in vitro.

Predictors of HIV-associated nephropathy

Renal disease accounts for significant morbidity and mortality in patients with HIV-1 infection. HIV-associated nephropathy (HIVAN) is an important cause of end stage renal disease in this population. Although multiple genetic, clinical, and laboratory characteristics such as Apolipoproetin-1 genetic polymorphism, high viral load, low CD-4 count, nephrotic range proteinuria, and increased renal echogenicity on ultrasound are predictive of HIVAN, kidney biopsy remains the gold standard to make the definitive diagnosis. Current treatment options for HIVAN include initiation of combined active antiretroviral therapy, blockade of the renin-angiotensin system, and steroids. In patients with progression of HIVAN, renal transplant should be pursued as long as their systemic HIV infection is controlled.

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

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

Renal diseases in haemophilic patients: pathogenesis and clinical management

Haemophilia A and B are genetic X-linked bleeding disorders, caused by mutations in genes encoding factors VIII and IX, respectively. Clinical manifestations of haemophilia are spontaneous haemorrhage or acute bleeding caused by minor trauma, resulting in severe functional consequences that can culminate in a debilitating arthropathy. Life expectancy and quality of life of patients with haemophilia have dramatically improved over the last years, mainly for new therapeutic options and the awareness to the risk of HCV and HIV infections. Different clinical problems arise from this important change in history of patients with haemophilia. In particular, ageing-related diseases, such as diabetes, hypertension and cancer, and chronic viral infections are emerging as new challenges in this patient population. Among the different types of chronic illnesses, renal diseases are of special interest as they involve some difficult management issues. In fact, decisions regarding adequate preventive strategies and viral infection treatment, the choice of the dialytic modality, placement of vascular access and prescription of dialytic treatments are particularly complicated, because only few data are available. In this review, we discuss the pathogenesis of renal damage in patients with haemophilia, especially in those with blood-transmitted viral infections, and the major issues about the management of renal diseases, including problems related to dialytic treatment and kidney transplantation, providing practical algorithms to guide the clinical decision-making process.

mTOR plays a critical role in p53-induced oxidative kidney cell injury in HIVAN

Oxidative stress has been implicated to contribute to HIV-induced kidney cell injury; however, the role of p53, a modulator of oxidative stress, has not been evaluated in the development of HIV-associated nephropathy (HIVAN). We hypothesized that mammalian target of rapamycin (mTOR) may be critical for the induction of p53-mediated oxidative kidney cell injury in HIVAN. To test our hypothesis, we evaluated the effect of an mTOR inhibitor, rapamycin, on kidney cell p53 expression, downstream signaling, and kidney cell injury in both in vivo and in vitro studies. Inhibition of the mTOR pathway resulted in downregulation of renal tissue p53 expression, associated downstream signaling, and decreased number of sclerosed glomeruli, tubular microcysts, and apoptosed and 8-hydroxy deoxyguanosine (8-OHdG)-positive (+ve) cells in Tg26 mice. mTOR inhibition not only attenuated kidney cell expression of p66ShcA and phospho-p66ShcA but also reactivated the redox-sensitive stress response program in the form of enhanced expression of manganese superoxide dismutase (MnSOD) and catalase. In in vitro studies, the mTOR inhibitor also provided protection against HIV-induced podocyte apoptosis. Moreover, mTOR inhibition downregulated HIV-induced podocyte (HP/HIV) p53 expression. Since HP/HIV silenced for mTOR displayed a lack of expression of p53 as well as attenuated podocyte apoptosis, this suggests that mTOR is critical for kidney cell p53 activation and associated oxidative kidney cell injury in the HIV milieu.

Role of traditional risk factors and antiretroviral drugs in the incidence of chronic kidney disease, ANRS CO3 Aquitaine cohort, France, 2004-2012

Objective

To examine the role of antiretroviral drugs (ART), HIV-related and traditional risk factors on the incidence of chronic kidney disease (CKD) in HIV-infected patients.

Design

Prospective hospital-based cohort of HIV-infected patients from 2004 to 2012.

Methods

CKD was defined using MDRD equation as an estimated glomerular filtration rate (eGFR) less than 60 ml/mn/1.73 m² at 2 consecutive measurements ≥3 months apart. Poisson regression models were used to study determinants of CKD either measured at baseline or updated. ART exposure was classified as ever or never. We additionally tested the role of tenofovir (TDF), whether or not prescribed concomitantly with a Protease Inhibitor (PI), taking into account the cumulative exposure to the drug.

Results

4,350 patients (74% men) with baseline eGFR>60 ml/mn/1.73 m² were followed for a median of 5.8 years. At the end of follow-up, 96% had received ART, one third of them (35%) jointly received TDF and a PI. Average incidence rate of CKD was 0.95% person-years of follow-up. Incidence of CKD was higher among women (IRR = 2.2), older patients (>60 y vs <45 y: IRR = 2.5 and 45–60 y: IRR = 1.7), those with diabetes (IRR = 1.9), high blood pressure (IRR = 1.5), hyperlipidemia (IRR = 1.5), AIDS stage (IRR = 1.4), low baseline eGFR (IRR = 15.8 for 60<eGFR<70 ml/mn/1.73 m² vs >90 and IRR = 7.1 for 70<eGFR<80 ml/mn/1.73 m²), current CD4+<200 cells/mm³ vs >500/mm³ (IRR = 2.5), and exposure to TDF (IRR = 2.0). Exposure to TDF was even strongly associated with CKD when co-administered with PIs (IRR = 3.1 vs 1.3 when not, p<0,001). A higher risk of CKD was found when tenofovir exposure was >12 months [IRR = 3.0 with joint PIs vs 1.3 without (p<0.001)]. A vast majority of those developing CKD (76.6%) had a baseline eGFR between 60 and 80 ml/mn/1.73 m².

Conclusion

In patients with eGFR between 60 and 80 mL/min/1.73 m², a thorough control of CKD risk factors is warranted. The use of TDF, especially when co-administered with PIs, should be mentioned as a relative contraindication in presence of at least one of these risk factors.

The clinical and histological response of HIV-associated kidney disease to antiretroviral therapy in South Africans

BACKGROUND

Little is known about the progression of kidney disease in HIV-infected patients in developing countries in the era of antiretroviral therapy (ART).

METHODS

HIV-infected patients were screened for kidney disease. Kidney biopsies were performed before and after initiation of ART to assess the clinical and histological response to treatment. Data were collected from all participants in accordance with the study protocol. The mean follow-up was 2.4 patient years on ART.

RESULTS

There was a rapid immunological and renal response to ART. The renal response was reflected by a significant rise in the estimated glomerular filtration rate (eGFR) and rapid regression of proteinuria. The histological patterns were highly variable, ranging from non-specific lesions such as mesangial hyperplasia and interstitial nephritis to HIV-immune complex disease (HIV-ICD) with or without features of HIV-associated nephropathy (HIVAN). In the follow-up biopsies, the histological response to treatment was variable with a combination of no change, progression or regression of lesions.

CONCLUSIONS

This study demonstrated a spectrum of renal histological lesions in HIV-associated kidney disease. Initiation of ART produced a rapid and sustained clinical renal response in all participants, irrespective of the histology. Follow-up biopsies showed an inconsistent histological response of lesions to treatment. In lesions that regressed, there appeared to be a discrete lag in histological response when compared with the rapid clinical response.

Renal dysfunction in the setting of HIV/AIDS

Antiretroviral therapy has been immensely successful in reducing the incidence of opportunistic infections and death after HIV infection. This has resulted in heightened interest in noninfectious comorbidities including kidney disease. Although HIV-associated nephropathy, the most ominous kidney disease related to the direct effects of HIV, may be prevented and treated with antiretrovirals, kidney disease remains an important issue in this population. In addition to the common risk factors for kidney disease of diabetes mellitus and hypertension, HIV-infected individuals have a high prevalence of other risk factors, including hepatitis C and exposure to antiretrovirals and other medications. Therefore, the differential diagnosis is vast. Early identification (through efficient screening) and prompt treatment of kidney disease in HIV-infected individuals are critical to lead to better outcomes. This review focuses on clinical and epidemiological issues, treatment strategies (including dialysis and kidney transplantation), and recent advances among kidney disease in the HIV population.

Antiretroviral therapy adherence and drug-drug interactions in the aging HIV population

It is estimated that by 2015 more than half of all HIV-infected individuals in the United States will be 50 years of age or older. As this population ages, the frequency of non-AIDS related comorbidities increases, which includes cardiovascular, metabolic, gastrointestinal, genitourinary and psychiatric disorders. As a result, medical management of the aging HIV population can be complicated by polypharmacy and higher pill burden, leading to poorer antiretroviral therapy (ART) adherence. Adherence to ART is generally better in older populations when compared to younger populations; however, cognitive impairment in elderly patients can impair adherence, leading to worse treatment outcomes. Practical monitoring tools can improve adherence and increase rates of viral load suppression. Several antiretroviral drugs exhibit inhibitory and/or inducing effects on cytochrome P450 isoenzymes, which are responsible for the metabolism of many medications used for the treatment of comorbidities in the aging HIV population. The combination of ART with polypharmacy significantly increases the chance of potentially serious drug-drug interactions (DDIs), which can lead to drug toxicity, poorer ART adherence, loss of efficacy of the coadministered medication, or virologic breakthrough. Increasing clinicians awareness of common DDIs and the use of DDI programs can prevent coadministration of potentially harmful combinations in elderly HIV-infected individuals. Well designed ART adherence interventions and DDI studies are needed in the elderly HIV population.

Determinants of incident chronic kidney disease and progression in a cohort of HIV-infected persons with unrestricted access to health care

OBJECTIVES

As socioeconomic factors may impact the risk of chronic kidney disease (CKD), we evaluated the incidence and risk factors of incident CKD among an HIV-infected cohort with universal access to health care and minimal injecting drug use (IDU).

METHODS

Incident CKD was defined as an estimated glomerular filteration rate (eGFR) <60 ml/min/1.73 m(2) for ≥ 90 days. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Rates were calculated per 1000 person-years (PY). Associations with outcomes were assessed using two separate Cox proportional hazard models, adjusting for baseline and time-updated covariates.

RESULTS

Among 3360 participants [median age 29 years; 92% male; 44% African American (AA)] contributing 23,091 PY of follow-up, 116 developed incident CKD [5.0/1000 PY; 95% confidence interval (CI) 4.2-6.0/1000 PY]. The median first eGFR value was 97.0 mL/min/1.73 m(2) [interquartile range (IQR) 85.3-110.1 mL/min/1.73 m(2)]. Baseline factors associated with CKD included older age, lower CD4 count at HIV diagnosis [compared with CD4 count ≥ 500 cells/μL, hazard ratio (HR) 2.1 (95% CI 1.2-3.8) for CD4 count 350-499 cells/μL; HR 3.6 (95% CI 2.0-6.3) for CD4 count 201-349 cells/μL; HR 4.3 (95% CI 2.0-9.4) for CD4 count ≤ 200 cells/μL], and HIV diagnosis in the pre-highly active antiretroviral therapy (HAART) era. In the time-updated model, low nadir CD4 counts, diabetes, hepatitis B, hypertension and less HAART use were also associated with CKD. AA ethnicity was not associated with incident CKD in either model.

CONCLUSIONS

The low incidence of CKD and the lack of association with ethnicity observed in this study may in part be attributable to unique features of our cohort such as younger age, early HIV diagnosis, minimal IDU, and unrestricted access to care. Lower baseline CD4 counts were significantly associated with incident CKD, suggesting early HIV diagnosis and timely introduction of HAART may reduce the burden of CKD.