HIV therapy, metabolic and cardiovascular health are associated with glomerular hyperfiltration among men with and without HIV infection

Feasibility of Emergency Department-Initiated HIV Pre-Exposure Prophylaxis

Introduction

Pre-exposure prophylaxis (PrEP) for HIV-using antiretroviral medication in non-infected individuals to prevent HIV-has immense potential to slow the spread of the virus. However, uptake has been insufficient, and stark racial disparities exist in both HIV acquisition and PrEP usage, making PrEP access a health equity issue. A promising venue to engage high-risk populations in PrEP care is the emergency department (ED); however, existing ED PrEP initiatives have been costly or have had limited success. We hypothesize that two strategies could overcome these barriers: prescribing PrEP during an ED visit and providing patients with an initial supply of PrEP medication in the ED. Here, we describe the results of a qualitative study exploring multidisciplinary emergency clinicians and HIV clinicians' needs and views about the feasibility of such an initiative.

Methods

We conducted 22 semi-structured interviews with multidisciplinary clinicians from an urban, safety-net medical center in the ED and the on-site HIV clinic that provides PrEP services. We performed thematic analysis to summarize challenges and potential solutions described by participants.

Results

Participants' responses fell into three thematic categories: operational challenges; patient-level considerations; and potential impacts. Operational challenges highlighted the difficulty of PrEP initiation in a busy ED and clinician support needs. Patient-level considerations included the complex psychosocial needs of ED patients who could benefit from PrEP. Finally, participants anticipated that an ED-based PrEP initiation program could positively impact both individual patients and public health.

Conclusion

Interviews with emergency department and HIV clinic staff revealed important considerations and potential solutions for ED-initiated PrEP workflows. Clinicians in both specialties were enthusiastic about such an initiative, which could facilitate its success. This study lays the groundwork for the future design of an efficient and innovative workflow to leverage the ED as an essential entry point into HIV prevention services.

Current and Novel Biomarkers of Progression Risk in Children with Chronic Kidney Disease

BACKGROUND

Due to the complexity of chronic kidney disease (CKD) pathophysiology, biomarkers representing different mechanistic pathways have been targeted for the study and development of novel biomarkers. The discovery of clinically useful CKD biomarkers would allow for the identification of those children at the highest risk of kidney function decline for timely interventions and enrollment in clinical trials.

SUMMARY

Glomerular filtration rate and proteinuria are traditional biomarkers to classify and prognosticate CKD progression in clinical practice but have several limitations. Over the recent decades, novel biomarkers have been identified from blood or urine with metabolomic screening studies, proteomic screening studies, and an improved knowledge of CKD pathophysiology. This review highlights promising biomarkers associated with the progression of CKD that could potentially serve as future prognostic markers in children with CKD.

KEY MESSAGES

Further studies are needed in children with CKD to validate putative biomarkers, particularly candidate proteins and metabolites, for improving clinical management.

Predictive Risk Model for Serious Falls Among Older Persons Living With HIV

BACKGROUND

Older (older than 50 years) persons living with HIV (PWH) are at elevated risk for falls. We explored how well our algorithm for predicting falls in a general population of middle-aged Veterans (age 45-65 years) worked among older PWH who use antiretroviral therapy (ART) and whether model fit improved with inclusion of specific ART classes.

METHODS

This analysis included 304,951 six-month person-intervals over a 15-year period (2001-2015) contributed by 26,373 older PWH from the Veterans Aging Cohort Study who were taking ART. Serious falls (those falls warranting a visit to a health care provider) were identified by external cause of injury codes and a machine-learning algorithm applied to radiology reports. Potential predictors included a fall within the past 12 months, demographics, body mass index, Veterans Aging Cohort Study Index 2.0 score, substance use, and measures of multimorbidity and polypharmacy. We assessed discrimination and calibration from application of the original coefficients (model derived from middle-aged Veterans) to older PWH and then reassessed by refitting the model using multivariable logistic regression with generalized estimating equations. We also explored whether model performance improved with indicators of ART classes.

RESULTS

With application of the original coefficients, discrimination was good (C-statistic 0.725; 95% CI: 0.719 to 0.730) but calibration was poor. After refitting the model, both discrimination (C-statistic 0.732; 95% CI: 0.727 to 0.734) and calibration were good. Including ART classes did not improve model performance.

CONCLUSIONS

After refitting their coefficients, the same variables predicted risk of serious falls among older PWH nearly and they had among middle-aged Veterans.

Estimated glomerular filtration rate is a prognosticator of adverse outcomes after primary total knee arthroplasty among patients with chronic kidney disease and glomerular hyperfiltration

BACKGROUND

The goals of this study were: (1) to test whether patients with an Estimated glomerular filtration rate (eGFR) that is higher or lower than population-based standards have an increased risk of 30-day mortality, return to the operating room, readmission, non-home discharge, any complication, major complications, and minor complications after primary total knee arthroplasty (TKA); and (2) to find out whether there is a significant non-linear relationship between eGFR and those same variables.

METHODS

A total of 168,919 primary TKAs were identified using The National Surgical Quality Improvement Program (NSQIP) database between 1 January 2008 and 31 December 2016. The following outcomes were assessed at 30 days: mortality, return to the operating room, readmission, non-home discharge, any complication, major complications, and minor complications.

RESULTS

Multivariate binomial logistical regression found that patients with hyperfiltration had higher rates of readmission (P < 0.03), non-home discharge (P < 0.01), any complication (P < 0.01), major complications (P = 0.03), and minor complications (P < 0.01) compared to reference patients with eGFR in the normal range. Patients with an eGFR less than 60 (stage 3 chronic kidney disease or higher) had increased odds of mortality (P < 0.05), readmission (P < 0.05), any complication (P < 0.01), major complications (P < 0.01), and minor complications (P < 0.01). Spline regression found statistically significant non-linear relationships between eGFR and mortality (P < 0.001), return to the operating room (P = 0.0029), and readmission as well as non-home discharge (P < 0.001).

CONCLUSION

Low eGFR and hyperfiltration may be associated with elevated risk of 30-day adverse events. GFR can be used as a risk stratification tool to counseling patients with particular attention paid to those with a GFR < 30 ml/min/1.73 m².

Tenofovir disoproxil fumarate associated nephrotoxicity: a retrospective cohort study at two referral hospitals in Namibia

INTRODUCTION

The incidence and risk factors of tenofovir disoproxil fumarate (TDF)-related renal impairment (RI) in Namibia are unknown where TDF-containing ART regimens are used as the first line for HIV.

METHODOLOGY

A retrospective cohort study among HIV-infected patients at two intermediate hospitals. A decline in estimated glomerular filtration rate (eGFR) was significant if it was ≥25% and included a change to a lower eGFR stage. New-onset RI was defined as an eGFR <50 mL/min/1.73m² .

RESULTS

10 387 patients were included: 11.4% (n = 1182) experienced the decline in eGFR. Of these, 0.6% (n = 62) migrated to eGFR stages IV and V. The incidence was 4.5 (95% CI: 4.3-4.8) per 100 patient years. RI developed in 400 patients for an incidence rate of 2.4 (95% CI: 2.2-2.6) cases per 100 patient years. Risk factors with effect sizes >2.0, for decline-in-eGFR were baseline eGFR >60 (aHR = 15.6); hyperfiltration (aHR = 5.0); and pregnancy (aHR = 2.4); while for RI, they were hyperfiltration (aHR = 4.1) and pregnancy (aHR = 29).

CONCLUSION

The incidence of decline-in-eGFR was higher than in other sub-SSA countries, but not RI. A high baseline eGFR had the greatest risk for the decline, and hyperfiltration for the RI.

Validation of a simple equation for glomerular filtration rate measurement based on plasma iohexol disappearance

Background

A simple equation for glomerular filtration rate (GFR) measurement based on only plasma samples during the slow compartment after injection of iohexol was previously developed among children with chronic kidney disease and adult men with or at risk of HIV infection [Chronic Kidney Disease in Children (CKiD)-Multicenter AIDS Cohort Study (MACS) equation], but has not been externally validated. We aimed to evaluate the performance of the CKiD-MACS equation among elderly participants in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort who underwent directly measured iohexol GFR.

Methods

Using data from 287 participants of the MESA-Kidney study who underwent a five-sample measured iohexol GFR (two and three samples in the fast and slow compartments, respectively), we assessed the performance of the CKiD-MACS equation using only plasma samples in the slow compartment by sex, race and age. Agreement was assessed by bias, correlation, proportion within 5 and 10%, and the root mean square error (RMSE).

Results

The average age and GFR of the participants were 71 years and 70.8 mL/min/1.73 m², respectively, and 46% were black. The equation yielded excellent agreement within stratified groups with high correlation (>0.96), low bias (≤1.2 mL/min/1.73 m²) and low RMSE (<4.2 mL/min/1.73 m²).

Conclusions

The CKiD-MACS equation demonstrated valid GFR measurement using only samples in the slow compartment in this racially diverse, elderly population. While the equation yielded practically the same results as the original Brochner-Mortensen equation, the CKiD-MACS equation conforms to theoretical principles embedded in the two-compartment model of direct GFR measurement.

A 10-year follow-up study of demographic and cardiometabolic factors in HIV-infected South Africans

OBJECTIVES

Understanding of the interplay between human immunodeficiency virus (HIV) and cardiovascular disease, especially in Africa, is limited to evidence from longitudinal studies. Therefore the demographic profile and cardiometabolic, renal and liver function of an HIV-infected South African population were profiled from 2005 to 2015.

METHODS

The study included 117 HIV-infected and 131 uninfected controls that were examined at baseline, five and 10 years.

RESULTS

Mortality rate declined from 24% (2005-2010) to 0% (2010-2015) after the introduction of ART. Longitudinal increases in C-reactive protein (p = 0.002), alanine transaminase (p = 0.006) and gamma-glutamyl transferase (p = 0.046) levels and estimated glomerular filtration rate (p < 0.001) were seen only in the HIV-infected group. This group also showed increased high-density lipoprotein cholesterol (HDL-C) (p < 0.001) and total cholesterol (p < 0.001) levels and decreased triglyceride:HDL-C (p = 0.011) levels. Low-density lipoprotein cholesterol decreased in both groups (p < 0.001).

CONCLUSIONS

Despite trajectories of deranged lipid and inflammatory profiles, the cardiometabolic disease risk seems stable in HIV-infected South Africans. Inflammation and renal and liver function warrant regular monitoring.

Estimating glomerular filtration rate in youth with obesity and type 2 diabetes: the iCARE study equation

BACKGROUND

The validity of pediatric estimated glomerular filtration rate equations (eGFRs) in early stages of CKD including hyperfiltration is unknown. The purpose of this study was to develop an eGFR equation for adolescents with obesity and type 2 diabetes (T2D).

METHODS

eGFRs were developed from iohexol-derived GFRs (iGFRs) in 26 overweight/obese (BMI > 85th percentile) youth and 100 with T2D from the iCARE (Improving renal Complications in Adolescents with T2D through REsearch) cohort. Twenty percent of the cohort was withheld as a validation dataset. Linear regression analyses were used to develop the best formula based on body size, sex, creatinine, urea, ± cystatin C. Comparable validity of commonly used eGFR equations was assessed.

RESULTS

Mean age 15.4 + 2.4 years, BMI Z-score 2.5 + 1.2, 61% female, and mean iGFR 129.0 + 27.7 ml/min/ 1.73 m². The best adjusted eGFR formula (ml/min/1.73 m²) was 50.7 × BSA^0.816 × (height (cm)/creatinine)^0.405 × 0.8994 if sex = female | 1 otherwise. It resulted in 53.8% of eGFRs within 10% of measured iGFR and 96.2% within 30%. Bland-Altman 95% limits of agreement in the external dataset were - 37.6 to 45.5 ml/min/1.73m² (bias = 3.96), and the correlation was 0.62. This equation performed better than all previously published creatinine-based eGFRs. cystatin C did not significantly improve results; however, some other cystatin C formulas also performed well.

CONCLUSIONS

The iCARE equation provides a more accurate creatinine-based eGFR in obese youth with and without T2D. Further studies are warranted to evaluate within-subject variability and applicability to lower GFRs and other populations.

Long-term kidney function, proteinuria, and associated risks among HIV-infected and uninfected men

BACKGROUND

Factors affecting kidney function and proteinuria among HIV-positive (HIV+) and HIV-negative (HIV-) persons need better characterization.

METHODS

We evaluated estimated glomerular filtration rate (eGFR, ml/min per 1.73 m) changes, proteinuria prevalence (a urine protein-to-creatinine ratio of ≥0.2 at two consecutive visits) and associated factors among HIV+ and HIV- men.

RESULTS

There were 917 HIV+ men receiving HAART, 159 HIV+ men not receiving HAART, and 1305 HIV- men seen from October 2003 to September 2014. Median annual eGFR change was -0.5, -0.8% for HIV+ and -0.3% for HIV- men (P < 0.001). Factors significantly (P < 0.05) associated with more than 3% annual eGFR decline were HAART receipt (but no specific antiretroviral drug), age more than 50, hypertension, diabetes, current smoking. Proteinuria existed in 14.9% of visit-pairs among HAART recipients, 5.8% among non-HAART recipients, and 1.9% among HIV- men, and was associated with subsequent annual more than 3% eGFR decline (odds ratio 1.80, P < 0.001). Proteinuria-associated factors also included HAART use (vs. HIV-), age at least 50 (vs. <40), diabetes, hypertension, current smoking, hepatitis C virus-infection (all P < 0.05) and, among HIV+ men, lower CD4 cell count, didanosine, saquinavir, or nelfinavir use (all P < 0.05). After adjusting for proteinuria, among HAART users, having a detectable HIV RNA, cumulative use of tenofovir disoproxil fumarate, emtricitabine, ritonavir, atazanavir, any protease inhibitor, or fluconazole were associated with more than 3% annual eGFR decline.

CONCLUSION

Longitudinal kidney function decline was associated with HAART use but no individual antiretroviral drug, and traditional kidney disease risks. Proteinuria was nearly seven times more common in HAART-treated men than HIV- men, reflected recent eGFR decline and predicted subsequent eGFR decline.

Relationships of Measured Iohexol GFR and Estimated GFR With CKD-Related Biomarkers in Children and Adolescents

BACKGROUND

2 valid and reliable estimated glomerular filtration rate (GFR) equations for the pediatric population have been developed from directly measured GFR data in the Chronic Kidney Disease in Children (CKiD) cohort: the full CKiD and bedside CKiD equations. Although adult GFR estimating equations replicate relationships of measured GFR with biomarkers, it is unclear whether similar patterns exist among children and adolescents with chronic kidney disease (CKD).

STUDY DESIGN

Prospective cohort study in children and adolescents.

SETTINGS & PARTICIPANTS

730 participants contributed 1,539 study visits.

PREDICTORS

Measured GFR by plasma iohexol disappearance (mGFR), estimated GFR by the full CKiD equation (eGFR_CKiDfull; based on serum creatinine, cystatin C, serum urea nitrogen, height, and sex), and estimated GFR by the bedside CKiD equation (eGFR_CKiDbed; calculated as 41.3 × height [m]/serum creatinine [mg/dL]) were predictors of CKD-related biomarkers. Deviations of mGFR from eGFR_CKiDfull and deviations of eGFR_CKiDfull from eGFR_CKiDbed from linear regressions (ie, residuals) were included in bivariate analyses.

OUTCOMES & MEASUREMENTS

CKD-related biomarkers included values for urine protein-creatinine ratio, blood hemoglobin, serum phosphate, bicarbonate, potassium, systolic and diastolic blood pressure z scores, and height z scores.

RESULTS

The median age of 730 participants with CKD was 12.5 years, with median mGFR, eGFR_CKiDfull, and eGFR_CKiDbed of 51.8, 54.0, and 53.2mL/min/1.73m², respectively. eGFR_CKiDfull demonstrated as strong or stronger associations with CKD-related biomarkers than mGFR; eGFR_CKiDbed associations were significantly attenuated (ie, closer to the null). Residual information in mGFR did not substantially increase explained variability. eGFR_CKiDbed estimated faster GFR decline relative to mGFR and eGFR_CKiDfull.

LIMITATIONS

Simple linear summaries of biomarkers may not capture nonlinear associations.

CONCLUSIONS

eGFR_CKiDfull closely approximated mGFR to describe relationships with CKD-severity indicators and progression in this pediatric CKD population. eGFR_CKiDbed offered similar inferences, but associations were attenuated and rate of progression was overestimated. The eGFR_CKiDfull equation from 2012 is preferred for pediatric research purposes.

Inflammation, Immune Activation, Immunosenescence, and Hormonal Biomarkers in the Frailty-Related Phenotype of Men With or at Risk for HIV Infection

Background

The extent to which inflammation, immune activation/immunosenescence, and hormonal abnormalities are driven by human immunodeficiency virus (HIV) or frailty is not clear.

Methods

HIV-infected frail men (n = 155) were matched to nonfrail, HIV-infected (n = 141) and HIV-uninfected (n = 150) men by age, calendar year, and antiretroviral therapy use (HIV-infected men only). Frailty was defined by ≥3 frailty-related phenotype criteria (weight loss, exhaustion, low activity, slowness) at ≥2 visits, or at 1 visit with ≥1 criteria at ≥2 visits. The following measurements were obtained: interleukin 6, high-sensitivity C-reactive protein, soluble receptors for tumor necrosis factor α 1 and 2, the percentages of CD4+CD28-, CD8+CD28-, CD4+CD38+HLA-DR+, and CD8+CD38+HLA-DR+ T cells, dehydroepiandrosterone sulfate, free testosterone, homeostatic model assessment of insulin resistance, and insulin-like growth factor 1. Log-linear regressions were adjusted for a priori selected covariates to determine differences by frailty and HIV status.

Results

In multivariate analyses adjusted for covariates, frailty was associated among HIV-infected men with higher interleukin 6 and high-sensitivity C-reactive protein and lower free testosterone and dehydroepiandrosterone levels. In contrast, HIV infection but not frailty was associated with significantly greater immune senescence (percentage of CD4+CD28- or CD8+CD28- T cells) and immune activation (percentages of CD4+CD38+HLA-DR+ and CD8+CD38+HLA-DR+ T cells).

Conclusions

Frailty among HIV-infected men was associated with increased inflammation and lower hormone levels, independent of comorbid conditions. Interventions targeting these pathways should be evaluated to determine the impact on prevention or reversal of frailty among HIV-infected men.

Associations between plasma tenofovir concentration and renal function markers in HIV-infected women

Background

Tenofovir disoproxil fumarate (TDF) has been associated with kidney tubular dysfunction and reduced renal function. Limited studies were performed in Europe and Asia that related plasma tenofovir (TFV) concentration with renal function; no such studies to date have been performed on Africans.

Objective

To investigate the correlation between plasma tenofovir (TFV) concentration and certain renal function markers in HIV-infected women on TDF antiretroviral therapy (ART). These markers were also compared to a HIV-uninfected control group.

Methods

HIV-infected women (n = 30) on TDF-based ART were matched with 30 controls for age and body mass index. Renal markers analysed were estimated glomerular filtration rate (eGFR), creatinine clearance (CrCl), serum creatinine, albuminuria, glucosuria, serum urea, serum uric acid, urine sodium and maximum tubular reabsorption of phosphate. Baseline eGFR and CrCl data were obtained retrospectively for the HIV-infected women. Plasma TFV was assayed using a validated HPLC-MS/MS method. Stepwise regression, Mann-Whitney test, unpaired and paired t-tests were applied in the statistical analyses.

Results

TFV concentration was independently associated with albuminuria (adjusted r² = 0.339; p = 0.001) in HIV-infected women. In the adjusted (weight) analysis, eGFR (p = 0.038), CrCl (p = 0.032) and albuminuria (p = 0.048) were significantly higher in HIV-infected compared to the uninfected women, but eGFR was abnormally high in HIV-infected women. Both eGFR (p < 0.001) and CrCl (p = 0.008) increased from baseline to follow-up in HIV-infected women.

Conclusion

Plasma TFV concentration was associated with increased albuminuria in HIV-infected women in this sub-study. Both eGFR and CrCl were increased in HIV-infected women from baseline. These findings should be confirmed in larger studies, and hyperfiltration in HIV-infected women warrants further investigation.

Renal abnormalities in a cohort of HIV-infected children and adolescents

BACKGROUND

This study aimed to identify the prevalence of renal abnormalities and the evolution of glomerular filtration rate (GFR) among human immunodeficiency virus (HIV)- infected children and adolescents followed up in an infectious disease outpatient pediatric clinic.

METHODS

We performed a cohort study of 115 children and adolescents. Outcomes of two evaluations for urinalysis, microalbuminuria/urinary creatinine ratio, urinary retinol-binding protein (uRBP) concentration, and estimated GFR (eGFR) were obtained for each patient, with an average interval of 6 months between evaluations. These changes were correlated with gender, age, race, body mass index (BMI), height-for-age (H/A) percentile, clinical and immunological classification of HIV infection, use of antiretroviral therapy (ART), HIV viral load (VL), and CD4+ T-lymphocyte count.

RESULTS

Mean patient age at the time of inclusion in the study was 12.6 ± 3.2 years; 50.4 % were male, 81.7 % had acquired immune defeciency syndrome (AIDS), 80.9 % had CD4+ < 500 cells/mm(3), and 87.8 % were on ART. Urinary changes included hematuria (11.3 %), proteinuria (7 %), and microalbuminuria (11.6 %); uRBP was present in 3.8 %; and mean eGFR was 163 ± 32 ml/min/1.73 m(2).

CONCLUSIONS

The subclinical renal abnormalities found in this study may indicate early manifestations of a broad spectrum of renal dysfunction associated with HIV and involves the decision to initiate or modify ART.

MicroRNA biomarkers in clinical renal disease: from diabetic nephropathy renal transplantation and beyond

Chronic Kidney Disease (CKD) is a common health problem affecting 1 in 12 Americans. It is associated with elevated risks of mortality, cardiovascular disease, and high costs for the treatment of renal failure with dialysis or transplantation. Advances in CKD care are impeded by the lack of biomarkers for early diagnosis, assessment of the extent of tissue injury, estimation of disease progression, and evaluation of response to therapy. Such biomarkers should improve the performance of existing measures of renal functional impairment (estimated glomerular filtration rate, eGFR) or kidney damage (proteinuria). MicroRNAs (miRNAs) a class of small, non-coding RNAs that act as post-transcriptional repressors are gaining momentum as biomarkers in a number of disease areas. In this review, we examine the potential utility of miRNAs as promising biomarkers for renal disease. We explore the performance of miRNAs as biomarkers in two clinically important forms of CKD, diabetes and the nephropathy developing in kidney transplant recipients. Finally, we highlight the pitfalls and opportunities of miRNAs and provide a broad perspective for the future clinical development of miRNAs as biomarkers in CKD beyond the current gold standards of eGFR and albuminuria.

Factors associated with iohexol-based glomerular filtration rate slope over 36 months in HIV-negative and HIV-positive individuals

BACKGROUND

Monitoring kidney function is important in HIV-positive persons, but creatinine-based estimates of glomerular filtration rate (GFR) have limitations. There are little to no data available assessing GFR trends in HIV-positive persons using a gold-standard measure of GFR.

METHODS

We measured GFR based on iohexol plasma disappearance (iGFR) annually for 3 years in nondiabetic, HIV-negative and HIV-positive volunteers with normal estimated kidney function. We used mixed linear models to evaluate factors associated with baseline iGFR and iGFR slope.

RESULTS

One hundred HIV-negative and 191 HIV-positive, predominantly black individuals (median age 49 years) participated in the study and completed a total of 960 iGFR assessments over a median of 36 months. Despite similar estimated GFR at baseline, average iGFR values were lower in HIV-positive compared with HIV-negative participants (103.2 vs. 110.8, ml/min/1.73 m, P = 0.004). However, subsequent iGFR slope was not significantly different in HIV-positive and HIV-negative participants. In the HIV-positive group, the presence of carotid plaque and hepatitis C virus coinfection were associated with significantly lower iGFR values at baseline. A nonsuppressed HIV RNA level at baseline was associated with a significantly more rapid iGFR decline compared with individuals with HIV RNA less than 400 copies/ml (-4.69 vs. -1.31 ml/min per 1.73 m per year, P = 0.005). Other factors significantly associated with iGFR slope included albuminuria and glycosylated hemoglobin.

CONCLUSION

Compared with HIV-negative persons, HIV-positive participants had significantly lower baseline iGFR, despite similar estimated GFR in the two groups. Nonsuppressed HIV RNA at baseline was associated with a more rapid iGFR decline over 3 years.

Kidney Dysfunction and Markers of Inflammation in the Multicenter AIDS Cohort Study

BACKGROUND

Human immunodeficiency virus (HIV)-infected individuals are at higher risk for chronic kidney disease than HIV-uninfected individuals. We investigated whether the inflammation present in treated HIV infection contributes to kidney dysfunction among HIV-infected men receiving highly active antiretroviral therapy.

METHODS

The glomerular filtration rate (GFR) was directly measured (using iohexol) along with 12 markers of inflammation in Multicenter AIDS Cohort Study participants. Exploratory factor analysis was used to identify inflammatory processes related to kidney dysfunction. The estimated levels of these inflammatory processes were used in adjusted logistic regression analyses evaluating cross-sectional associations with kidney function outcomes.

RESULTS

There were 434 HIV-infected men receiving highly active antiretroviral therapy and 200 HIV-uninfected men. HIV-infected men were younger (median age, 51 vs 53 years) and had higher urine protein-creatinine ratios (median, 98 vs 66 mg/g) but comparable GFRs (median, 109 vs 106 mL/min|1.73 m(2)). We found an inflammatory process dominated by markers: soluble tumor necrosis factor receptor 2, soluble interleukin 2 receptor α, soluble gp130, soluble CD27, and soluble CD14. An increase of 1 standard deviation in that inflammatory process was associated with significantly greater odds of GFR ≤90 mL/min/1.73 m(2) (odds ratio, 2.0) and urine protein >200 mg/g (odds ratio, 2.3).

CONCLUSIONS

Higher circulating levels of immune activation markers among treated HIV-infected men may partially explain their higher burden of kidney dysfunction compared with uninfected men.

Proteinuria is associated with neurocognitive impairment in antiretroviral therapy treated HIV-infected individuals

BACKGROUND

Proteinuria is a marker of vascular dysfunction that predicted increased cardiovascular mortality and is associated with neurocognitive impairment (NCI) in population-based studies. We examined associations between proteinuria and HIV-associated NCI.

METHODS

Multivariable logistic regression was used to examine associations between NCI at the first neurocognitive assessment (baseline) and simultaneous, clinically significant proteinuria [as random spot urine protein-to-creatinine ratios (UP/Cr) ≥200 mg/g] in a prospective multicenter observational cohort study. Generalized estimating equations were used to examine associations between baseline proteinuria and subsequent NCI among subjects without NCI at baseline. NCI was defined as a Z-score, derived from the combination of normalized scores from the Trailmaking A and B and the Wechsler Adult Intelligence Scale-Revised Digit Symbol tests.

RESULTS

A total of 1972 subjects were included in this analysis. Baseline proteinuria was associated with increased odds of NCI [odds ratio (OR): 1.41, 95% confidence interval (CI): 1.08 to 1.85; P = 0.01] and with subsequent NCI among subjects without NCI at baseline (OR: 1.39, 95% CI: 1.01 to 1.93; P = 0.046) in multivariable models adjusted for risk factors and potential confounders. Similar associations were evident when these analyses were limited to visits at which time study subjects maintained plasma HIV RNA levels <200 copies per milliliter.

CONCLUSIONS

The association between proteinuria and NCI observed in this study adds to a growing body of evidence implicating contributions by vascular disease to NCI in antiretroviral treated individuals. Studies examining interventions that improve vascular function are warranted.

Identifying the appropriate comparison group for HIV-infected individuals

PURPOSE OF REVIEW

HIV-infected individuals are living longer as a result of effective treatment. Age-related comorbidities now account for the majority of morbidity and mortality among treated HIV-infected adults. Previous findings regarding the age at, and risk of, these comorbidities have been mixed, sparking debate in the field. Discerning potential differences in the occurrence and burden of age-related comorbidities among treated HIV-infected adults as compared with uninfected adults of the same age requires careful selection of the appropriate uninfected comparison group.

RECENT FINDINGS

The validity of comparisons with HIV-uninfected populations is threatened when differences in demographic, clinical, and lifestyle characteristics between HIV-infected and uninfected adults are not considered. Identifying a pool of HIV-uninfected individuals from existing secondary data resources and employing selection methodologies may be a novel approach to reduce threats to internal validity. Issues related to identifying data sources, understanding inclusion criteria, determining measurement error, and threats to inference are discussed.

SUMMARY

The development of clinical interventions targeting age-related comorbidities will rely on deriving valid inferences from appropriate comparison groups. The use of secondary data resources and selection methodology to create the appropriate uninfected comparison group is an attractive approach in the setting of finite resources, but are not without limitations.