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

Chronic kidney disease as a global public health problem: approaches and initiatives - a position statement from Kidney Disease Improving Global Outcomes

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. There is now convincing evidence that CKD can be detected using simple laboratory tests, and that treatment can prevent or delay complications of decreased kidney function, slow the progression of kidney disease, and reduce the risk of cardiovascular disease (CVD). Translating these advances to simple and applicable public health measures must be adopted as a goal worldwide. Understanding the relationship between CKD and other chronic diseases is important to developing a public health policy to improve outcomes. The 2004 Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on 'Definition and Classification of Chronic Kidney Disease' represented an important endorsement of the Kidney Disease Outcome Quality Initiative definition and classification of CKD by the international community. The 2006 KDIGO Controversies Conference on CKD was convened to consider six major topics: (1) CKD classification, (2) CKD screening and surveillance, (3) public policy for CKD, (4) CVD and CVD risk factors as risk factors for development and progression of CKD, (5) association of CKD with chronic infections, and (6) association of CKD with cancer. This report contains the recommendations from the meeting. It has been reviewed by the conference participants and approved as position statement by the KDIGO Board of Directors. KDIGO will work in collaboration with international and national public health organizations to facilitate implementation of these recommendations.

Renal complications in HIV

Highly Active Antiretroviral Therapy has revolutionised the care of individuals living with HIV-1. As the prognosis for this population has improved, there is an increased risk of other major causes of morbidity and mortality, including renal disease. This review discusses the frequency and causes of renal pathology, how to make the diagnosis and monitor for renal disease in HIV-infected individuals. The review was conducted having examined the key evidence focussing upon HIV and renal complications obtained from peer-reviewed journals (level of evidence I-IV). As the population of individuals living with HIV increases, so too does the prevalence of renal disease. Physicians should be vigilant and recognise individuals at risk of renal complications, and be aware of how to monitor, investigate and treat those affected.

Microalbuminuria in HIV infection

OBJECTIVE

Microalbuminuria is associated with increased risk of cardiovascular disease and mortality. The objective of the study was to evaluate if HIV infection was an independent risk factor for microalbuminuria.

DESIGN

Cross sectional.

METHODS

The relationship between HIV infection and microalbuminuria was assessed using subjects enrolled in the study of Fat Redistribution and Metabolic Change in HIV Infection, which consists of HIV-positive and control men and women. Participants with proteinuria (dipstick >or= 1+) were excluded.

RESULTS

Microalbuminuria (urinary albumin/creatinine ratio, ACR > 30 mg/g) was present in 11% of HIV infected, and 2% of control participants (P < 0.001); a fivefold odds after multivariate adjustment (odds ratio, 5.11; 95% confidence interval, 1.97-13.31; P=0.0008). Several cardiovascular risk factors were associated with higher ACR in HIV participants: insulin resistance (HOMA > 4; 32%, P < 0.0001), systolic blood pressure (21%, P = 0.01 for 120-140 versus < 120 mmHg, and 43%, P = 0.06 for > 140 versus < 120 mmHg), and family history of hypertension (17%, P = 0.03). Higher CD4 cell count was associated with lower albumin/creatinine ratio (-24%, P = 0.009 for 200-400 versus < 200 cells/ml and -26%, P = 0.005 for > 400 versus < 200 cells/ml).

CONCLUSION

HIV infection had a strong and independent association with microalbuminuria, the severity of which was predicted by markers of insulin resistance, hypertension, and advanced HIV infection. These associations warrant further investigation, as the increased prevalence of microalbuminuria in HIV infection may be a harbinger of future risk of cardiovascular and kidney diseases.

Urinary beta2-microglobulin as a possible sensitive marker for renal injury caused by tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate (TDF) is renally excreted by a combination of glomerular filtration and active tubular secretion, and its renal safety profiles have been reported based on a limited increase of serum creatinine (sCr) levels. However, renal tubular function has not previously been well monitored. We measured sCr and urinary beta2-microglobulin (U-beta2MG) levels cross-sectionally in 70 patients treated with TDF [TDF+] and 90 patients on other antiretroviral therapy who had never been exposed to TDF [TDF-]. The mean U-beta2MG was significantly higher in TDF+ patients than that in TDF- patients (p < 0.0001), though no statistical difference was detected in their creatinine clearance estimated by using the Cockcroft-Gault equation. Multivariate analysis showed that coadministration of boosted lopinavir (LPV) and patients' body weight were associated with U-beta 2MG levels in TDF+ patients. U-beta2MG levels were significantly higher in those who also received boosted LPV [TDF+LPV+] (p = 0.0007), and abnormally high levels were noted in 67.7% of them. Furthermore, in the TDF+LPV+ group, U-beta2MG levels showed significant negative correlation with patients' body weight (p = 0.0029) and abnormal U-beta2MG was observed in all six patients with body weight less than 55 kg. In four patients, a rapid fall in U-beta2MG occurred after cessation of TDF. Relative to sCr, U-beta2MG could be a more sensitive marker of renal tubular injury caused by TDF. Boosted LPV co-administration and low body weight may be risk factors for TDF-induced renal tubular dysfunction, probably because these factors are associated with an increase in TDF concentration.

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.

Risk factors and causes of death in the Australian HIV Observational Database

Introduction: Mortality rates in HIV-infected people remain high in the era of highly active antiretroviral treatment (HAART). The objective of this paper was to examine causes of deaths in the Australian HIV Observational Database (AHOD) and compare risk factors for HIV-related and HIV-unrelated deaths. Methods: Data from AHOD, an observational study of people with HIV attending medical sites between 1999 and 2004, were analysed. Primary and underlying causes of death were ascertained by sites completing a standardised cause of death form. Causes of death were then coded as HIV-related or HIV-unrelated. Risk factors for HIV-related and unrelated deaths were assessed using survival analysis among patients who had a baseline and at least one follow-up CD4 and RNA measure. Results: The AHOD had enrolled 2329 patients between 1999 and 2004. During this time, a total of 105 patients died, with a crude mortality rate of 1.58 per 100 person years. Forty-two (40%) deaths were HIV-related (directly attributable to an AIDS event), 55 (52%) HIV-unrelated (all other causes), and eight had unknown cause of death. Independent risk factors for HIV-related deaths were low CD4 count and receipt of a larger number of antiretroviral treatment combinations. Among HIV-unrelated deaths, low CD4 count and older age were independent risk factors. Conclusions: In AHOD in the HAART era, mortality in people with HIV remains around 10-fold higher than in the general population. In our analyses, HIV-unrelated deaths were associated with more advanced HIV disease in a similar way to HIV-related deaths.

[Assessment of renal abnormalities in 107 HIV patients treated with tenofovir]

OBJECTIVES

The objectives of our study were to assess frequency, severity and outcome of renal abnormalities, as well as to determine the risk of developing hypophosphataemia in HIV-infected patients receiving tenofovir.

METHODS

An observational study was conducted in real-life conditions, during a 6-month period, in 107 HIV patients receiving tenofovir.

RESULTS

Mild-to-moderate hypophosphataemia (<0.77 mmol/L) occurred during follow-up, at least once in 43% of patients and at least twice in 27%. Antiretroviral therapy including ritonavir + lopinavir was significantly associated with the occurrence of hypophosphataemia (relative risk = 2.6; p = 0.03). Frequency of abnormal proteinuria was 22%.

CONCLUSION

Creatinine clearance, phosphataemia, proteinuria and glycosuria should be closely monitored in patients receiving tenofovir therapy.

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.

Factors associated with chronic renal failure in HIV-infected ambulatory patients

OBJECTIVE

Renal disease is an increasingly common manifestation among HIV-positive persons, particularly during late stages of HIV disease. We performed a cohort-based, nested case-control study to examine the role of several factors in developing HIV-related chronic renal disease, including HIV viral load and CD4+ cell count.

DESIGN

Incident cases of chronic renal disease were identified from a cohort of 6361 prospectively followed HIV-1 positive persons. Controls were selected using incidence density sampling and matched 4:1 on age, race/ethnicity, and gender.

METHODS

Odds ratios (OR) and 95% confidence intervals (CI) were obtained using conditional logistic regression.

RESULTS

One hundred and eight cases of chronic renal disease were identified; 80 (74.1%) were eligible for the current analysis. Nadir CD4+ cell count < 200 x 10(6) cells/l (OR = 4.3; 95% CI, 2.1-8.7), highly active antiretroviral therapy (HAART) use for 56 days or more (OR = 0.5; 95% CI, 0.3-1.0), and hypertension [treated with angiotensin-converting enzyme (ACE) inhibitors: OR = 4.6; 95% CI, 1.8-11.6; treated with non-ACE inhibitors: OR = 2.5; 95% CI, 1.0-6.2; not treated: OR = 4.2; 95% CI, 0.8-21.6] were associated with disease. HAART use for 56 days or more modified the associations for nadir CD4+ cell count and hypertension.

CONCLUSIONS

Our findings suggest that advanced HIV-disease, as indicated by low CD4+ cell count, is associated with subsequently developing chronic renal disease and treatment with HAART may reduce the risk of developing chronic renal disease.

Association between renal disease and outcomes among HIV-infected women receiving or not receiving antiretroviral therapy

BACKGROUND

The associations of proteinuria and an elevated creatinine level with progression to acquired immunodeficiency syndrome (AIDS) and death in the era of highly antiretroviral therapy (HAART) have not been fully described.

METHODS

This analysis includes 2038 human immunodeficiency virus (HIV)-infected women from the Women's Interagency HIV Study. Time to the development of a new AIDS-defining illness (ADI) and death was modeled using proportional hazards regression before the widespread availability of HAART and after initiation of HAART.

RESULTS

Of the 2038 subjects, the 14.1% of women with proteinuria had lower CD4 lymphocyte counts and higher viral loads (P<.0001 for all) at baseline and before initiation of HAART. Before the widespread availability of HAART, proteinuria was associated with an increased risk for development of ADI (hazard ratio [HR], 1.37; P=.005), and proteinuria and an elevated creatinine level were both associated with an increased risk of death (for proteinuria: HR, 1.35 [P=.04]; for creatinine: HR, 1.72 per decrease in the inverse unit [P=.02]). Among women initiating HAART, an elevated creatinine level remained associated with an increased risk of development of ADI (HR, 1.54 per decrease in the inverse unit; P=.03), and proteinuria and an elevated creatinine level were associated with an increased risk of death (for proteinuria: HR, 2.07 [P=.005]; for creatinine: HR, 1.96 per decrease in the inverse unit [P=.04]).

CONCLUSIONS

Proteinuria and an elevated creatinine level were associated with an increased risk of death and development of ADI. These associations may reflect the direct role of the kidney in modulating HIV disease, or they may act as markers of greater comorbidity.

Renal safety of tenofovir in HIV treatment-experienced patients

The safety of tenovir disoproxil fumarate (TDF) was assessed in two double-blind, placebo-controlled studies. Furthermore, we retrospectively collected 19 cases of TDF-associated tubular dysfunction. The incidence of renal events was similar among the active TDF groups and the placebo group in the two double-blind, placebo-controlled studies. Proximal tubulopathy was diagnosed 6.89 +/- 5.51 months after TDF therapy started. All abnormalities normalized within 4.7 +/- 2.94 weeks after drug discontinuation.

Rates and Risk Factors for Condition-Specific Hospitalizations in HIV-Infected and Uninfected Women

BACKGROUND

The rates and risk factors for overall and medical condition-specific hospitalizations in HIV-positive women have not been examined in detail or compared with rates in risk factor-matched HIV-negative women.

OBJECTIVE

To determine the rates and risk factors for overall and condition-specific hospitalizations.

METHODS

Prospective cohort study of 885 HIV-positive women and 425 HIV-negative women followed for semiannual research visits between 1993 and 2000 in 4 urban locations in the United States. Outcome measures were hospitalization diagnoses with diabetes mellitus, nonacute renal conditions, cardiovascular conditions, liver conditions, AIDS defining conditions, and overall hospitalizations. Clinical and laboratory risk factors were assessed at research visits every 6 months, and effects of risk factors on hospitalization rates were calculated using generalized estimating equations and Poisson regression.

RESULTS

Renal laboratory abnormalities, hypertension, and clinical AIDS were each associated with 3 of the 5 condition-specific hospitalization rates. Over time, diabetes-, nonacute renal-, and cardiovascular-related rates were flat or slightly increased and liver-related rates were significantly increased in HIV-positive women. Hospitalization rates with an AIDS-defining condition declined sharply in the latter half of the study period.

CONCLUSIONS

In this population of largely African-American, inner-city, HIV-infected women, renal abnormalities, hypertension, and hepatitis C virus infection were common. Rate ratios indicated that "non-AIDS" risk factors were important predictors of hospitalization. In the highly active antiretroviral therapy era, clinicians must pay attention to these risk factors for morbidity and should closely monitor renal abnormalities, hypertension, and hepatitis status.