HIV dementia: an evolving disease

Several advances have led to improvements in the care and prognosis of HIV+ individuals. The first is an understanding of the direct relationship between HIV replication and subsequent immunological and clinical progression, reinforcing the need to completely suppress HIV replication to control disease progression. The second is the wider availability of HAART which can provide effective suppression of HIV. The third major change is the ability to monitor HAART through the reliable and widespread measurement of plasma HIV RNA levels, which has become a routine part of clinical care. Since the introduction of highly active antiretroviral therapy (HAART) in the 1990s, there have been significant declines in the incidence rates of opportunistic infections in developed countries. HAART has clearly improved survival for individuals with HIV/AIDS, and has reduced the incidence of HIV-associated dementia (HIV-D) by 40-50% (Brodt et al., 2002). The prevalence of sensory neuropathies in advanced HIV/AIDS now exceeds 20% (Schifitto et al., 2002), and may rise further with prolonged exposure to neurotoxic HAART. HIV-D and HIV-related sensory neuropathies (HIV-SN) have a combined prevalence of about 30-50% in advanced HIV disease, suggesting that HAART does not provide complete protection against neurological damage (Bouwman et al., 1998). HIV-associated dementia (HIV-D) remains a common cause of dementia worldwide, and with HIV-related sensory neuropathies (HIV-SN) represents the commonest neurological disorders associated with AIDS. Furthermore, the temporal progression of HIV-D appears to have been altered by HAART, with most patients now showing an attenuated form of dementia, which with treatment is slowly progressive or static (Dougherty et al., 2002). This overview will review some of the outstanding questions relating to HIV-dementia, including: (a) are there differing phenotypes or temporal patterns of progression in HIV-dementia? (b) what determines these temporal patterns? and (c), what has been the impact of therapy on HIV dementia?

The clinical epidemiology and course of the spectrum of renal diseases associated with HIV infection

BACKGROUND

While an understanding of the epidemiology and clinical course of HIV-associated nephropathy (HIVAN) is growing, little is known about the risk factors and clinical course of the other renal diseases that may also occur as a complication of HIV infection. This study was undertaken to compare HIVAN to the spectrum of other kidney diseases seen among HIV-infected patients.

METHODS

This retrospective cohort study included all HIV-infected patients who underwent renal biopsy during the course of their clinical care at six major medical centers. Demographic and clinical information were abstracted from each patient's clinical record. Time to initiation of renal replacement therapy was compared for patients with lesions other than HIVAN to patients with HIVAN using Cox proportional hazards regression.

RESULTS

Eighty-nine patients (47 with lesions other than HIVAN and 42 with HIVAN) were available for inclusion. Patients with lesions other than HIVAN were less likely to be black (37/47 vs. 42/42, P= 0.02), more likely to have a positive hepatitis B surface antigen (10/37 vs. 4/42, P= 0.04), less likely to have the diagnosis of hypertension (24/46 vs. 31/42, P= 0.03), more likely to have a greater creatinine clearance at time of biopsy (60.6 vs. 39.0 cc/min, P= 0.008), and have a greater CD4 lymphocyte count at time of biopsy (287 vs. 187 cells/mL, P= 0.04) compared to patients with HIVAN. Lesions other than HIVAN were associated with a longer time to initiation of renal replacement therapy compared with HIVAN (HR 0.33, 95% CI 0.15-0.71, P= 0.005). Other factors associated with a longer time to renal replacement therapy included higher creatinine clearance at time of biopsy, greater CD4(+) lymphocyte count, the absence of hepatitis C antibody, and the use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. The type of renal disease (HIVAN vs. other) interacted significantly with HIV-1 RNA level and the use of antiretroviral therapy (P= 0.0001 and 0.006, respectively). Among patients with lesions other than HIVAN, the presence of nondetectable HIV-1 RNA was not associated with a greater risk of progression of renal disease (HR 0.27, P= 0.24). Among patients with HIVAN, because all patients had detectable virus at the time of institution of renal replacement therapy, this highly significant association could not be quantified. Among patients with lesions other than HIVAN, the use of antiretroviral therapy was not associated with the progression to renal replacement therapy (HR 3.29, P= 0.06). Among patients with HIVAN, the use of antiretroviral therapy was associated with a slower progression to renal replacement therapy (HR 0.24, P= 0.03).

CONCLUSION

Among HIV-infected patients with renal disease other than HIVAN, viral suppression and the use of antiretroviral therapy are not associated with a beneficial effect on renal function; thus, additional therapeutic strategies may need to be utilized. Because renal histology is associated with prognostic differences, these data provide outcomes information that will improve the clinical utility of renal biopsy among HIV-infected patients with renal disease.

APOL1 variants associate with increased risk of CKD among African Americans

Although case-control studies suggest that African Americans with common coding variants in the APOL1 gene are 5-29 times more likely than those individuals without such variants to have focal segmental glomerulosclerosis, HIV-associated nephropathy, or ESRD, prospective studies have not yet evaluated the impact of these variants on CKD in a community-based sample of African Americans. Here, we studied whether the APOL1 G1 and G2 risk alleles associate with the development of CKD and progression to ESRD by analyzing data from 3067 African Americans in the Atherosclerosis Risk in Communities Study who did not have CKD at baseline. Carrying two risk alleles associated with a 1.49-fold increased risk of CKD (95% CI=1.02 to 2.17) and a 1.88-fold increased risk of ESRD (95% CI=1.20 to 2.93) compared with zero or one risk allele; associations persisted after adjusting for European ancestry. Among participants who developed CKD, those participants with two risk alleles were more likely to progress to ESRD than their counterparts with zero or one risk allele (HR=2.22, 95% CI=1.01 to 4.84). In conclusion, APOL1 risk variants are risk factors for the development of CKD and progression from CKD to ESRD among African Americans in the general population.

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

OBJECTIVE

to assess temporal changes in the incidence of human immunodeficiency virus-1-associated nephropathy (HIVAN), and the association with use of highly active antiretroviral therapy (HAART).

METHODS

HIVAN incidence and risk factors were assessed in 3976 HIV-1-infected individuals followed in clinical cohort in Baltimore, Maryland, USA from 1989 to 2001. The incidence of HIVAN, defined by biopsy or a conservative uniformly applied clinical coding protocol, was expressed in terms of person-years, and Poisson regression was used for multivariate analysis.

RESULTS

Ninety-four patients developed HIVAN over the course of the study for an incidence of 8.0 per 1000 person-years [95% confidence interval (CI), 6.5 to 9.8]. African American race and advanced immunosuppression were strongly associated with HIVAN risk. HIVAN incidence declined significantly in 1998-2001 compared with 1995-1997. Among patients with a prior diagnosis of AIDS, HIVAN incidence was 26.4, 14.4, and 6.8 per 1000 person-years in patients not receiving antiretroviral therapy, treated with nucleoside analogue therapy only, or treated with HAART, respectively (P < 0.001 for trend). In multivariate analysis, HIVAN risk was reduced 60% (95% CI, -30 to -80%) by use of HAART, and no patient developed HIVAN when HAART had been initiated prior to the development of AIDS.

CONCLUSION

HAART was associated with a substantial reduction in HIVAN incidence. Additional follow-up will be needed to determine if renal damage in susceptible individuals is halted or merely slowed by HAART, particularly when control of viremia is incomplete or intermittent.

Nephropathy in human immunodeficiency virus-1 transgenic mice is due to renal transgene expression

HIV-associated nephropathy (HIVAN) is a progressive glomerular and tubular disease that is increasingly common in AIDS patients and one of the leading causes of end stage renal disease in African Americans. A major unresolved issue in the pathogenesis of HIVAN is whether the kidney disease is due to renal cell infection or a "bystander" phenomenon mediated by systemically dysregulated cytokines. To address this issue, we have used two different experimental approaches and an HIV-1 transgenic mouse line that develops a progressive renal disease histologically similar to HIVAN in humans. In the murine model, kidney tissue expresses the transgene and in heterozygous adults, renal disease develops shortly thereafter. We demonstrate by terminal deoxynucleotide transferase-mediated dUTP-biotin nick-end labeling assay that similar to the disease in humans, apoptosis of renal tubular epithelial cells is a component of the molecular pathogenesis. To determine whether apoptosis is due to transgene expression or environmental factors, we treated fetal kidney explants (normal and transgenic) with UV light to induce transgene expression. Apoptosis occurred in transgenic but not normal littermates after stimulation of transgene expression. To confirm a direct effect of HIV expression on the production of HIVAN, we transplanted kidneys between normal and transgenic mice. HIVAN developed in transgenic kidneys transplanted into nontransgenic littermates. Normal kidneys remained disease free when transplanted into transgenic littermates. Thus, the renal disease in the murine model is intrinsic to the kidney. Using two different experimental approaches, we demonstrate a direct effect of transgene expression on the development of HIVAN in the mouse. These studies suggest that in humans, a direct effect of HIV-1 expression is likely the essential cause of HIVAN, rather than an indirect effect of cytokine dysregulation.

A cross-sectional study of HIV-seropositive patients with varying degrees of proteinuria in South Africa

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is the most common finding on renal biopsy in HIV-infected black patients and is also the commonest cause of end-stage renal disease in these patients. Early detection of HIVAN may be beneficial in evaluating early treatment. This study examined the pattern of renal diseases in HIV-infected South Africans and also attempted to diagnose HIVAN at an early stage. In this single-center cross-sectional study, 615 HIV-infected patients were screened for proteinuria. Thirty patients with varying degrees of proteinuria underwent renal biopsy. Patients with diabetes mellitus, uncontrolled hypertension, known causes of chronic kidney disease, and serum creatinine above 250 mumol/l were excluded. Patients in this study were not on antiretroviral therapy. HIVAN was found in 25 (83%) patients. Six of them (24%) had microalbuminuria. Altogether, seven patients with persistent microalbuminuria were biopsied and six (86%) showed HIVAN. Other biopsy findings included membranoproliferative nephropathy in two (7%) and interstitial nephritis in three (10%). Four patients with HIVAN had associated membranous nephropathy. HIVAN is the commonest biopsy finding among our study patients with HIV infection who present with varying degrees of proteinuria. Microalbuminuria is a manifestation of HIVAN in our study patients. Therefore, microalbuminuria may be an early marker of HIVAN, and screening for its presence may be beneficial. Renal biopsy may be considered in seropositive patients who present with persistent microalbuminuria, especially with low CD4 counts irrespective of good renal function. This will allow diagnosis and treatment of HIVAN at an early stage and may prevent further disease progression.

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.

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.

Development of proteinuria or elevated serum creatinine and mortality in HIV-infected women

BACKGROUND

Data on the incidence and prognostic significance of renal dysfunction in HIV disease are limited.

OBJECTIVE

To determine the incidence of proteinuria and elevated serum creatinine in HIV-positive and HIV-negative women and to determine whether these abnormalities are predictors of mortality or associated with causes of death listed on the death certificate in HIV-positive women.

DESIGN

The incidence of proteinuria or elevated serum creatinine and mortality was assessed in a cohort of 885 HIV-positive women and 425 at-risk HIV-negative women.

SETTING

Women from the general community or HIV care clinics in four urban locations in the United States.

OUTCOME MEASURES

Creatinine of >or=1.4 mg/dL, proteinuria 2 or more, or both. Deaths confirmed by a death certificate (92%) or medical record/community report (8%).

RESULTS

At baseline, 64 (7.2%) HIV-positive women and 10 (2.4%) HIV-negative women had proteinuria or elevated creatinine. An additional 128 (14%) HIV-positive women and 18 (4%) HIV-negative women developed these abnormalities over the next (mean) 21 months. Relative hazards of mortality were significantly increased (adjusted relative hazard = 2.5; 95% confidence interval: 1.9-3.3), and there were more renal causes recorded on death certificates (24/92 (26%) vs. 3/127 (2.7%), p<.0001) in HIV-infected women with, compared with those without these renal abnormalities.

CONCLUSIONS

Proteinuria, elevated serum creatinine, or both frequently occurred in these HIV-infected women. These renal abnormalities in HIV-infected women are associated with an increased risk of death after controlling for other risk factors and with an increased likelihood of having renal causes listed on the death certificate. The recognition and management of proteinuria and elevated serum creatinine should be a priority for HIV-infected persons.

HIV-related nephropathy: a South African perspective

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is an important cause of renal failure in those of African origin. A number of other kidney diseases occur in HIV-positive patients. We conducted a retrospective review of renal biopsies in HIV-positive Black African patients to determine the prevalence of both 'classic HIVAN' and non-HIVAN pathologies in this group. Clinical and laboratory data from HIV-positive patients who underwent renal biopsy from 1st January 2003 to 31st December 2004 were collected. Similar information on HIV-negative patients biopsied during the same period was also recorded by way of comparison to try and assess the influence of the virus on renal histologic patterns. HIV-positive group - 99 biopsies were suitable for study. The main histologic categories were 'classic HIVAN' (27%) and HIV immune complex kidney disease ('HIVICK') (21%). The subepithelial immune deposits in 'HIVICK' induced a newly described 'ball-in-cup' basement membrane reaction. Other glomerulonephritides included membranous, post-infectious disease, mesangial hyperplasia, and immunoglobulin A nephropathy. Overlapping clinical presentations prevented pre-biopsy histologic predictions. HIV-negative group - There were no examples of collapsing focal segmental glomerulosclerosis or nonspecific immune complex disease, but increased numbers of minimal change and membranoproliferative disease. 'Classic HIVAN' accounted for less than a third of the nephropathies occurring in HIV-positive Black South Africans. 'HIVICK' is another important cause of chronic kidney disease in this group. Future research is needed into the earlier detection and treatment of these diseases, which have a high mortality in our context.

Renal disease associated with HIV infection: a multicentric study of 60 patients from Paris hospitals

Sixty HIV-infected patients presenting renal symptoms who underwent percutaneous renal biopsies were analysed. According to the CDC classification, 44 patients were staged in group IV, five in group III, and 11 in group II. Patients were divided in two groups according to their ethnic origin (29 black patients and 31 white patients). Risk factors such as homosexuality, multiple transfusions or intravenous drug abuse (IVDA) were identified in all white patients except two, but in only nine (31%) of the black patients. Three main patterns of renal disease were observed: focal and segmental glomerulosclerosis (FSGS) was found predominantly in black patients (23 black patients versus 3 Caucasians, P < 0.001) and was associated with the nephrotic syndrome; immune-complex-type glomerulonephritis (ICGN) was frequent in black and white patients (21% and 52% respectively) including four cases of IgA nephritis all seen in white patients; and 10 cases of lupus-like nephritis (4 black and 6 white patients). The frequent hypergammaglobulinaemia in those patients suggests a pathogenic role of polyclonal B cell activation in ICGN. Interstitial nephritis was present in 48 and 52% of the black and white patients respectively and did not seem related to drug toxicity or superimposed infectious disease. In addition to interstitial nephritis, the coexistence of multivisceral lymphocytic infiltration involving accessory salivary glands, liver and/or lung, found in six patients possibly suggests a virus-induced immune disorder.

HIV-associated nephropathy: clinical presentation, pathology, and epidemiology in the era of antiretroviral therapy

The classic kidney disease of human immunodeficiency virus (HIV) infection, HIV-associated nephropathy, is characterized by progressive acute renal failure, often accompanied by proteinuria and ultrasound findings of enlarged, echogenic kidneys. Definitive diagnosis requires kidney biopsy, which shows collapsing focal segmental glomerulosclerosis with associated microcystic tubular dilatation and interstitial inflammation. Podocyte proliferation is a hallmark of HIV-associated nephropathy, although this classic pathology is observed less frequently in antiretroviral-treated patients. The pathogenesis of HIV-associated nephropathy involves direct HIV infection of renal epithelial cells, and the widespread introduction of combination antiretroviral therapy has had a significant impact on the natural history and epidemiology of this unique disease. These observations have established antiretroviral therapy as the cornerstone of treatment for HIV-associated nephropathy in the absence of prospective clinical trials. Adjunctive therapy for HIV-associated nephropathy includes angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, as well as corticosteroids in selected patients with significant interstitial inflammation or rapid progression.

Prevalence of HIV-associated nephropathy in autopsies of HIV-infected patients

Previous studies have reported that approximately 10% of the patients with human immunodeficiency virus (HIV) infection develop HIV-associated nephropathy (HIVAN). However, over the last decade, morbidity and mortality as a result of HIV-1 infection has remarkably decreased with the availability of potent new antiretroviral drugs. We therefore determined the prevalence of HIVAN from autopsy data of HIV-infected patients in more recent years (1992 to 1997). Autopsy reports of 389 patients were reviewed. In reports suggestive of possible HIVAN, slides of renal tissue were retrieved and reviewed again to ensure appropriate classification. The criteria for the diagnosis of HIVAN were focal segmental glomerulosclerosis with collapse of the glomerular tuft in some glomeruli, extensive tubular ectasia, and significant tubulointerstitial disease. Of 389 autopsy reports, 54% of the patients were black, 35% were white, and 11% were Hispanic. Thirty-three percent of the patients had a history of intravenous drug abuse. The mean CD4 count of the patients was 54 +/- 91/microL (mean +/- SD). In 27 cases, typical features of HIVAN were found based on the criteria used, accounting for an overall HIVAN prevalence of 6.9% (27 of 389 autopsies). Because the overwhelming majority of these patients were black (93%), the prevalence in blacks was 12% (25 of 209 autopsies). We conclude that although mortality and morbidity from HIV infection is decreasing, HIVAN remains an important complication of HIV infection in blacks, even in recent years.

Human immunodeficiency virus-associated glomerulosclerosis

The constellation of nephrotic proteinuria, FSGS, and rapid loss of renal function in a patient infected with HIV-1 has been sufficiently widespread and well documented to justify identification as a specific renal syndrome, HIV-associated nephropathy. The position paper of the National Kidney Foundation-National Institutes of Health task force estimated in 1990 that 10,000 to 15,000 persons will develop renal disease in association with AIDS [94]. Management of these patients is complex, and many will reach ESRD and require dialysis treatment, posing additional care problems. Greater understanding of the pathogenesis of the renal disease should lead to treatments which will forestall the development of HIVAN and possibly other forms of fibrotic renal disease. The ultimate eradication of AIDS will consign this renal syndrome to an interesting footnote in the history of nephrology. Since that time is still far in the future, nephrologists will continue to be faced with the need to diagnose and treat HIV-1-infected patients with renal involvement.

Is the prevalence of HIV-associated nephropathy decreasing?

Initial reports have suggested that approximately 10% of patients with HIV-infection develop HIV-associated nephropathy (HIVAN). It has also been predicted that by the end of the decade, HIVAN is likely to become a third leading cause of end-stage renal disease (ESRD) in African-Americans between the ages of 20-64 years. As the morbidity and mortality from HIV-infection has decreased in the last few years, it is possible that prevalence of HIVAN is also changing. We therefore screened HIV-1-infected patients followed in our hospital for HIVAN. A screening urinalysis was performed in 557 HIV-1-infected adult patients between March and May 1998. Of these, 252 were outpatients and 305 were Texas Department of Criminal Justice inmates (TDCJI). Demographic and laboratory data of these patients was obtained from the HIV patients' database. Fifty percent of the patients were African-American, 36.6% were Caucasian and 12. 7% were Hispanic. The mean age of patients was 37 +/- 8 years. Seventy-nine percent of the patients were males and a history of intravenous drug abuse (IVDA) was present in 28%. Twenty-three percent of the patients were concomitantly infected with hepatitis C virus, 4.1% were positive for hepatitis B surface antigen, and rapid plasma reagin test for syphilis was positive in 9.1%. In 38 patients who had more than 100 mg/dl (2+) proteins on screening urinalysis, total urinary proteins were quantitated by collecting 24 h urine specimens. Fifteen of these patients had urinary proteins more than 1.5 g/day (12 patients >3.5 g/24 h and 3 patients >1.5 g/24 h). A renal biopsy was done in 14 of these patients and clinical diagnosis of HIVAN was made in one patient who refused biopsy. Renal biopsies revealed HIVAN [9], diabetic nephropathy [2], membranoproliferative glomerulonephritis [2], Fibrillary glomerulonephritis [1]. All 10 patients (5 TDCJI and 5 outpatients) with HIVAN were African-American. Two of these 10 patients had a history of IVDA and another two were concomitantly infected with hepatitis C virus. The plasma viral load (Pvl) and total CD4 count was not different in patients with or without HIVAN [(Pvl log 10.05 +/- 1.39 vs. 9.9 +/- 2.18 copies/ml, p = 0.78) (CD4: 187 +/- 192 vs. 288 +/- 249 cells/microl, p = 1.17) mean +/- SD]. We conclude that in our HIV-infected population HIVAN exclusively affected African-Americans and the prevalence in them was 3.5%.

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

AIMS

While angiotensin-con-verting enzyme inhibitors and zidovudine may improve the course of the most common HIV-related renal disease, HIV-associated nephropathy (HIVAN), the effect of anti-retroviral combination therapy on this and other HIV-related renal diseases has not been assessed. This study describes the clinical course of HIV-related renal diseases and the effect of protease inhibitors on their progression.

METHODS

This retrospective cohort study reviews the clinical course of 19 patients with a clinical or biopsy-proven diagnosis of HIVAN or other HIV-related renal diseases. Groups progressing and not progressing to ESRD were compared using longitudinal analyses to assess the association between creatinine clearance and clinical and therapeutic factors.

RESULTS

The cohort consisted of 16 African-Americans, 2 Caucasians and 1 Native American. Their modes of HIV infection were intravenous drug use (7), a history of men having sex with men (3) and heterosexual behavior (5). Patients were followed for a median of 16.6 months. Seven patients reached ESRD. Loss of creatinine clearance over time did not differ among genders, races, or patients with different modes of HIV infection. Longitudinal analyses demonstrated an association between protease inhibitors and prednisone and a slower decline in creatinine clearance in multivariable models (p = 0.04 and 0.003, respectively).

CONCLUSIONS

The epidemiology and clinical course of HIV-related renal diseases is more heterogeneous than previously described. This study suggests a benefit to the use of protease inhibitors and prednisone on the progression of these nephropathies.

Absence of APOL1 risk variants protects against HIV-associated nephropathy in the Ethiopian population

BACKGROUND

Susceptibility to end-stage kidney disease (ESKD) among HIV-infected Americans of African ancestral heritage has been attributed to APOL1 genetic variation. We determined the frequency of the APOL1 G1 and G2 risk variants together with the prevalence of HIV-associated nephropathy (HIVAN) among individuals of Ethiopian ancestry to determine whether the kidney disease genetic risk is PanAfrican or restricted to West Africa, and can explain the previously reported low risk of HIVAN among Ethiopians.

METHODS

We studied a cohort of 338 HIV-infected individuals of Ethiopian ancestry treated in one Israeli and one Ethiopian center. We sought clinical evidence for HIVAN (serum creatinine >1.4 mg/dl or proteinuria >30 mg/dl in a spot urine sample). Genetic analyses included the genotyping of the APOL1 G1 and G2 variants, and a panel of 33 genomic ancestry-informative markers. Statistical analysis compared clinical and genetic indices for HIV-infected individuals of Ethiopian ancestry and overall Ethiopians to those reported for HIV-infected African-Americans, overall African-Americans, West Africans and non-Africans.

FINDINGS

Three (0.8%) of 338 HIV-infected patients of Ethiopian ancestry showed clinical criteria compatible with renal impairment. Two of these 3 patients also have severe poorly controlled diabetes mellitus. The third nondiabetic patient underwent renal biopsy which ruled out HIVAN. This absence of clinically apparent HIVAN was significantly different from that reported for African-Americans. The APOL1 G1 and G2 risk variants were found, respectively, in 0 and 2 (heterozygote state) of the 338 HIV-infected individuals. Global ancestry and the frequencies of the APOL1 G1 and G2 variants are not statistically different from their frequencies in the general Ethiopian population, but are significantly and dramatically lower than those observed among HIV-infected African-Americans, African-Americans and West Africans.

INTERPRETATION

The coinciding absence of HIVAN and the APOL1 risk variants among HIV-infected individuals of Ethiopian ancestry support a Western rather than Pan-African ancestry risk for ESKD, and can readily explain the lack of HIVAN among individuals of Ethiopian ancestry.

Zidovudine is beneficial in human immunodeficiency virus associated nephropathy

Human immunodeficiency virus associated nephropathy (Hivan) is a distinct renal disease described in patients infected with the human immunodeficiency virus (HIV). Hivan is characterized by a nephrotic syndrome, enlarged kidneys, a histologic finding of focal and segmental glomerulosclerosis, and a very rapid progression to end-stage renal disease (ESRD). No therapeutic intervention has been shown, in a prospective evaluation, to either alter the course of established Hivan or to influence the emergence of Hivan in HIV-infected patients. We conducted a prospective study on 23 consecutively selected patients seen between 1989 and 1992 who were infected with the HIV, 14 (61%) of whom had significant proteinuria (> or = 2+). Percutaneous kidney biopsy was performed in 5 (36%) of the 14 subjects who had significant proteinuria, and histologic examination of the kidney tissue revealed focal and segmental glomerulosclerosis in all 5 cases. Of the 14 subjects with proteinuria, 8 (57%) also had azotemia (serum creatinine level > or = 1.3 mg/dl). Nine (39%) of 23 subjects admitted intravenous drug use, while 9 (39%) of 23 subjects have had an opportunistic infection before enrollment in the study. The known duration of HIV infection before initiation of zidovudine therapy was 10.3 +/- (SD) 8 months. The mean CD4 count before zidovudine therapy was 195.9 +/- 117 (range 21-654) cells/mm3. The mean dose of zidovudine administered was 543 +/- 117 (range 400-800) mg daily for a period of 20.4 +/- 11 (range 6-38) months.(ABSTRACT TRUNCATED AT 250 WORDS)

HIV-associated nephropathy: Epidemiology, pathogenesis, and treatment

Initially described in 1984, human immunodeficiency virus-associated nephropathy (HIVAN) has now become a common disease within the HIV-seropositive population. It is a focal segmental glomerulosclerosis causing rapid deterioration of renal function. It is the most common cause of chronic renal disease in HIV patients and occurs almost exclusively in blacks. Through murine and human studies, it is now clear that HIVAN is caused by a direct effect of infection of renal cells by HIV-1 and that the virus actively replicates within renal cells. How the virus causes disease within cells is not yet understood, but there is evidence for factors within infected cells causing both proliferation and apoptosis. Steroids, angiotensin converting enzyme (ACE) inhibitors, and highly active antiretroviral therapy (HAART) have been used for the treatment of HIVAN, with HAART, in particular, showing a dramatic improvement in both the pathologic changes and clinical course of HIVAN.

Hypertension in the HIV-infected patient

HIV infection has reached endemic proportions in many African countries. In addition, HIV infection is a significant cause of renal dysfunction in the United States. HIV patients are at higher risk of developing hypertension at a younger age than the general population. Predisposing factors for developing hypertension include vasculitis in small, medium, and large vessels in the form of leukocytoclastic vasculitis, and aneurysms of the large vessels such as the carotid, femoral, and abdominal aorta with impairment of flow to the renal arteries. A syndrome of acquired glucocorticoid resistance has been described in patients with HIV with hypercortisolism and a lower affinity of the glucocorticoid receptors. The syndrome is characterized clinically by weakness, hypertension or hypotension, and skin pigmentation changes. Acute and chronic renal failure is often associated with HIV infection. The associated dysfunction in water and salt handling often induces hypertension. Finally, atherosclerosis has been described in young adults with HIV infection secondary to receiving highly active antiretroviral therapy.

Renal disease in HIV-infected individuals

PURPOSE OF REVIEW

Highly active antiretroviral therapy (HAART) has resulted in a marked decrease in AIDS-related conditions and death. With improved survival, cardiovascular disease, hepatic, renal disease, and non-AIDS-related cancers represent an increasing burden for HIV-infected individuals.

RECENT FINDINGS

HIV-associated nephropathy (HIVAN), acute renal injury, HAART, and comorbid conditions such as hepatitis C, hypertension, and diabetes are among the multiple causes of renal disease. In HIVAN there is incomplete understanding of the interaction of the virus with renal cells and the host genetics leading to susceptibility to this form of renal dysfunction. There is agreement that a baseline estimated glomerular filtration should be obtained and that renal function should be monitored during antiretroviral therapy. There is, however, no agreement as to the most accurate method of estimating GFR. Renal transplantation has emerged as a feasible and successful modality of management of end-stage renal disease (ESRD) in HIV-infected individuals.

SUMMARY

Kidney disease represents an increasing concern in the care of HIV-infected persons, although there are questions remaining regarding the pathophysiology of HIVAN. Transplantation, however, can be carried out safely in infected persons with ESRD.

Incidence of persistent renal dysfunction in human immunodeficiency virus-infected children: associations with the use of antiretrovirals, and other nephrotoxic medications and risk factors

BACKGROUND

Survival of HIV-infected children continues to increase and the use of antiretrovirals (ARVs) is expanding; however there are few data regarding the incidence of renal dysfunction and associated risk factors among HIV-infected children and youth.

METHODS

A total of 2102 children enrolled in Pediatric AIDS Clinical Trials Group Study 219/219C, were followed and assessed prospectively for >30 months. Occurrence of clinical events and laboratory abnormalities were recorded using standardized criteria and forms. Therapeutic decisions were made by clinicians at each site. Occurrence of persistent renal laboratory abnormalities was the main outcome measure.

RESULTS

Four hundred forty-six (22%) enrollees exhibited at least one persistent renal laboratory abnormality. Elevated serum creatinine (Cr) was more common than persistent proteinuria (15% vs. 8%). The incidence of new renal laboratory abnormalities was 3.7 events per 100 person-years with rates increasing between 1993 and 2005. Older age (>or=6 years vs. <6 years), Hispanic ethnicity, and Black non-Hispanic race were associated with increased risk of renal dysfunction, but CDC clinical class and plasma HIV RNA levels were not. Subjects exposed to ARV regimens containing tenofovir and/or indinavir had approximately twice the risk of developing renal dysfunction compared with persons exposed to other ARVs. The risk of renal dysfunction was also elevated for other antivirals (hazard ratio = 5.4) and amphotericin B (hazard ratio = 28).

CONCLUSIONS

Persistent renal function abnormalities occur frequently in HIV-infected children. Improved survival, Black race and Hispanic ethnicity, and exposure to tenofovir, indinavir, and other antimicrobial agents increase the risk for renal dysfunction. All HIV-infected children should be monitored closely for evidence of renal disease.

HIV-related metabolic comorbidities in the current ART era

Despite effective antiretroviral therapy (ART), HIV-infected individuals have residual chronic immune activation that contributes to the pathogenesis of HIV infection. This immune system dysregulation is a pathogenic state manifested by very low naïve T-cell numbers and increased terminally differentiated effector cells that generate excessive proinflammatory cytokines with limited functionality. Immune exhaustion leaves an individual at risk for accelerated aging-related diseases, including renal dysfunction, atherosclerosis, diabetes mellitus, and osteoporosis. We highlight research that clarifies the role of HIV, ART, and other factors that contribute to the development of these diseases among HIV-infected persons.

Diagnostic sonography of HIV-associated nephropathy: new observations and clinical correlation

OBJECTIVE

HIV-associated nephropathy is an important cause of morbidity that is characterized clinically by uremia and proteinuria and histologically by focal segmental glomerulosclerosis. In the largest series yet analyzed to our knowledge, we describe new sonographic findings and record the prevalence of other findings. We review the sonographic findings in a large group of HIV-infected patients.

MATERIALS AND METHODS

Seventy-six consecutive HIV-infected patients underwent renal sonography. Abnormalities seen on sonography were recorded.

RESULTS

Of 152 kidneys imaged, sonography showed that 30 kidneys (20%) were enlarged. Abnormal echogenicity was present in 136 kidneys (89%). Eighty-one kidneys (53%) were globular; 58 (38%) had decreased corticomedullary definition; 74 (49%) had decreased renal sinus fat; and 66 (43%) had heterogeneous parenchyma, some with echogenic striations.

CONCLUSION

Our data reveal several sonographic abnormalities that have not previously been described: decreased corticomedullary definition, decreased renal sinus fat, parenchymal heterogeneity, and globular renal configuration. These new findings were found mainly in patients with advanced HIV infection.