Screening for chronic kidney disease in HIV-infected patients

Renal safety of tenofovir alafenamide-based antiretroviral therapy in people with HIV: A mini-review

Antiretroviral therapy (ART) has significantly enhanced the outlook for people with HIV(PWH), yet certain ART medications can adversely affect the renal function of these patients. Of particular concern is the nephrotoxicity associated with tenofovir disoproxil fumarate (TDF). Compared to TDF, tenofovir alafenamide (TAF), another prodrug of tenofovir (TFV), results in lower TFV plasma levels, thereby alleviating the TFV-associated mitochondrial toxicity on proximal renal tubular cells. Currently, numerous clinical trials and real-world studies have demonstrated the favorable renal safety profile of ART regimens incorporating TAF for PWH. This paper seeks to consolidate the available evidence regarding the renal safety of TAF-based regimens in PWH, encompassing both the general PWH and those with renal impairment or predisposing factors, in order to offer recommendations and insights for TAF clinical application.

HIV-associated nephropathy in children: challenges in a resource-limited setting

HIV infection remains one of the leading causes of morbidity and mortality worldwide, especially in children living in resource-limited settings. Although the World Health Organization (WHO) recently recommended antiretroviral therapy (ART) initiation upon diagnosis regardless of the number of CD4, ART access remains limited, especially in children living in sub-Saharan Africa (SSA). HIV-infected children who do not receive appropriate ART are at increased risk of developing HIV-associated nephropathy (HIVAN). Although due to genetic susceptibility, SSA is recognized to be the epicenter of HIVAN, limited information is available regarding the burden of HIVAN in children living in Africa. The present review discusses the information available to date on the prevalence, pathogenesis, risk factors, diagnosis, and management of HIVAN in children, focusing on related challenges in a resource-limited setting.

Identifying Longitudinal CD4:CD8 Ratio Trajectories Indicative of Chronic Renal Disease Risk among People Living with HIV: An Application of Growth Mixture Models

The incidence of chronic kidney disease (CKD) is increasing among people living with HIV (PLWH). Routine monitoring of indicators such as CD4:CD8 ratio might improve the early detection of CKD. Our objective was to identify clinically relevant CD4:CD8 ratio trajectories indicative of CKD risk. Participants were ≥ 18 years old, initiated antiretroviral therapy between 2000 and 2016, and were followed for ≥6 months until 31 March 2017 or last contact date. Outcome was incidence of CKD. Growth mixture models (GMMs) and decay models were used to compare CD4:CD8 ratio trajectories. Following GMM, 4547 (93.5%) participants were classified in Class 1 with 5.4% developing CKD, and 316 (6.5%) participants were classified in Class 2 with 20.9% developing CKD. The final model suggested that participants in Class 2 had 8.72 times the incidence rate of developing CKD than those in Class 1. Exponential decay models indicated a significant CD4:CD8 ratio decline among Class 2 participants who developed CKD. Among those who developed CKD in Class 2, starting at 5.5 years of follow-up, the slope of their ratio trajectory curve changed significantly, and the rate of decline increased dramatically. Routine monitored CD4:CD8 ratios can be an effective strategy to identify early CKD risk among PLWH.

Incidence of impaired kidney function among people with HIV: a systematic review and meta-analysis

BACKGROUND

In the era of combination antiretroviral therapy (ART), the incidence, manifestations and severity of kidney diseases have dramatically changed in people living with HIV (PLWH). Little is known about the incidence of impaired kidney function (IKF) measured by serum creatine-based estimated glomerular filtration rate (eGFR) in PLWH.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Ovid, Medline, Embase and Web of Science for studies published before May 7th, 2021, with estimates of incidence of IKF among PLWH. We independently reviewed each study for quality by using the Newcastle-Ottawa scale. The incidence and 95% confidence intervals (CIs) were calculated using random-effects model.

RESULTS

Sixty out of 3797 identifiable studies were eligible for the meta-analysis. A total of 19 definitions of IKF were described and categorized into three types: the threshold of eGFR, an absolute or percent decrease in eGFR, and certain eGFR threshold combined with decrement in eGFR. The eGFR< 60 ml/min/1.73m2 was the most widely used definition or criterion for IKF, by which the pooled incidence rate of IKF was 12.50 (95%CI: 9.00-17.36) per 1000 person years (PYs). The second most-studied outcome was a > 25% decrease in eGFR, followed by eGFR< 90 ml/min/1.73m2, eGFR< 30 ml/min/1.73m2 and a combination of eGFR threshold plus decreased eGFR. The reported incidence rates of IKF differ widely by different definitions of IKF. The highest pooled incidence was observed for those with > 25% decrease in eGFR, while the lowest was observed in those with eGFR < 30 ml/min/1.73m2. Substantial heterogeneity was identified across most estimates.

CONCLUSION

Our study provides a comprehensive summary of eGFR-based definitions and incidence rates of IKF in PLWH, not only promoting our understanding of IKF, but also underscoring needs for a concerted action to unify definitions and outcomes of IKF and their applications in AIDS care.

GWAS in Mice Maps Susceptibility to HIV-Associated Nephropathy to the Ssbp2 Locus

BACKGROUND

To gain insight into the pathogenesis of collapsing glomerulopathy, a rare form of FSGS that often arises in the setting of viral infections, we performed a genome-wide association study (GWAS) among inbred mouse strains using a murine model of HIV-1 associated nephropathy (HIVAN).

METHODS

We first generated F1 hybrids between HIV-1 transgenic mice on the FVB/NJ background and 20 inbred laboratory strains. Analysis of histology, BUN, and urinary NGAL demonstrated marked phenotypic variation among the transgenic F1 hybrids, providing strong evidence for host genetic factors in the predisposition to nephropathy. A GWAS in 365 transgenic F1 hybrids generated from these 20 inbred strains was performed.

RESULTS

We identified a genome-wide significant locus on chromosome 13-C3 and multiple additional suggestive loci. Crossannotation of the Chr. 13 locus, including single-cell transcriptomic analysis of wildtype and HIV-1 transgenic mouse kidneys, nominated Ssbp2 as the most likely candidate gene. Ssbp2 is highly expressed in podocytes, encodes a transcriptional cofactor that interacts with LDB1 and LMX1B, which are both previously implicated in FSGS. Consistent with these data, older Ssbp2 null mice spontaneously develop glomerulosclerosis, tubular casts, interstitial fibrosis, and inflammation, similar to the HIVAN mouse model.

CONCLUSIONS

These findings demonstrate the utility of GWAS in mice to uncover host genetic factors for rare kidney traits and suggest Ssbp2 as susceptibility gene for HIVAN, potentially acting via the LDB1-LMX1B transcriptional network.

Selected biochemical parameters in the urine of HIV-infected patients in monitoring of kidney function

Introduction

For years, there has been an increase in the number of cases of chronic kidney disease (CKD) in human immunodeficiency virus (HIV)-infected patients. Renal dysfunction can be caused by direct effects of HIV on the kidneys but also of applied combined antiretroviral therapy (cART). Therefore there is a need of renal function diagnosis to monitor the development of kidney disturbances. In this study the urinary levels of selected low molecular weight proteins (LMWP) in HIV-infected patients were measured and related to current CD4+ T lymphocyte (LT CD4+) count, the glomerular filtration rate (eGFR) value and the applied cART.

Material and methods

The levels of 5 LMWP - kidney injury molecule-1 (KIM-1), neutrophil gelatinase associated lipocalin (NGAL), glutathione S-transferase α (GST-α) and π (GST-π) isoenzymes and neopterin (NPT) - in urine were measured in HIV-infected patients and healthy controls by enzyme-linked immunosorbent assay.

Results

Taking into account the current LT CD4+ count, KIM-1, NGAL and GST-α showed statistically significant differences between groups with the CD4+ count < 500 and ≥ 500 cells (< 0.001). Depending on the eGFR, apart from KIM-1 and NGAL, NPT showed statistically significant differences in the investigated groups with normal and lower eGFR values (< 0.001). In terms of applied cART, the best parameters in the assessment of kidney damage were NGAL, GST-π and NPT (< 0.001).

Conclusions

This research shows that the analyzed LMWP parameters are useful in the assessment of kidney damage in HIV patients during cART, especially NPT, NGAL and GST-π. However, future studies should be conducted on larger groups.

Renal doppler indices and their correlation with laboratory indices of human immunodeficiency virus sero-positive adult individuals

INTRODUCTION

Renal Doppler resistive index (RI) and pulsatility index (PI) values are potentially more sensitive at detecting renal abnormalities when compared to standard laboratory indices in patients with HIV/AIDS. To the best of our knowledge, there are no published research articles on renal Doppler indices and their correlation with laboratory indices of HIV sero-positive adult individuals. This study aimed to assess the renal function of HIV-sero-positive adults using RI and PI, and correlating these indices against laboratory values.

METHODS

A prospective cross-sectional study was conducted from July 2019 to April 2020. A purposive sampling method was employed and included 396 HIV sero-positive adult individuals. Sampling for the renal RI and PI was performed at the level of the inter-lober arteries, in between the medullary pyramids. An RI value above 0.70 and a PI value above 1.56 were consider abnormal. Serum creatine and urea together with evidence of proteinuria were recorded at the time of scanning.

RESULTS

Forty-three (10.9%) men had an abnormal RI, 32 (8.1%) had abnormal PI, five (2.5%) had abnormal creatinine, two (1%) abnormal urea and eight (4.1%) with proteinuria. In women, 29 (7.3%) had abnormal RI, 22 (5.6%) abnormal PI, four (2%) abnormal creatinine and urea and six (3%) had proteinuria. There was a statistically significant weak positive correlation between RI and PI and serum creatinine and urea (r > 0.2, P < 0.05).

CONCLUSION

The proportion of patients with abnormal RI and PI was higher than the proportion of participants with abnormal serum urea, creatinine and proteinuria. Renal Doppler indices could be used be used in the early assessment of renal function in HIV sero-positive adults individuals.

IMPLICATIONS FOR PRACTICE

Serum creatinine and urea are routinely used to evaluate renal function in patients with HIV/AIDS. Findings from this initial study show that RI and PI could be used detecting early renal abnormalities when compared to standard laboratory values.

Primary Care Guidance for Persons With Human Immunodeficiency Virus: 2020 Update by the HIV Medicine Association of the Infectious Diseases Society of America

Advances in antiretroviral therapy (ART) have made it possible for persons with human immunodeficiency virus (HIV) to live a near expected life span, without progressing to AIDS or transmitting HIV to sexual partners or infants. There is, therefore, increasing emphasis on maintaining health throughout the life span. To receive optimal medical care and achieve desired outcomes, persons with HIV must be consistently engaged in care and able to access uninterrupted treatment, including ART. Comprehensive evidence-based HIV primary care guidance is, therefore, more important than ever. Creating a patient-centered, stigma-free care environment is essential for care engagement. Barriers to care must be decreased at the societal, health system, clinic, and individual levels. As the population ages and noncommunicable diseases arise, providing comprehensive healthcare for persons with HIV becomes increasingly complex, including management of multiple comorbidities and the associated challenges of polypharmacy, while not neglecting HIV-related health concerns. Clinicians must address issues specific to persons of childbearing potential, including care during preconception and pregnancy, and to children, adolescents, and transgender and gender-diverse individuals. This guidance from an expert panel of the HIV Medicine Association of the Infectious Diseases Society of America updates previous 2013 primary care guidelines.

Proximal renal tubular function in HIV-infected children on tenofovir disoproxil fumarate for treatment of HIV infection at two tertiary hospitals in Harare, Zimbabwe

BACKGROUND

Renal abnormalities in HIV infected children may be due to the HIV infection or treatment among other factors. Tenofovir disoproxil fumarate (TDF) is associated with proximal renal tubular dysfunction, proteinuria and decrease in glomerular function. Studies in developed countries have shown variable prevalence of proximal renal tubular dysfunction in children on TDF. There are no known studies in developing countries, including Zimbabwe, documenting the proximal tubular function in HIV infected children on TDF. The aim of this study was to assess renal and proximal renal tubular function in HIV infected children receiving TDF and determine factors associated with proximal tubular dysfunction.

METHODS

A descriptive cross-sectional study was conducted in HIV infected patients below 18 years of age attending outpatient clinics at two tertiary hospitals in Harare, who received a TDF-containing antiretroviral regimen for at least six months. Dipstick protein and glucose, serum and urine phosphate and creatinine levels were measured. Fractional excretion of phosphate was calculated. Estimated glomerular filtration rate (eGFR) was calculated using the Schwartz formula. Tubular dysfunction was defined by at least two of the following characteristics: normoglycaemic glycosuria, hypophosphatemia and fractional excretion of phosphate > 18%.

FINDINGS

One hundred and ninety-eight children below 18 years of age were recruited over a period of six months. The prevalence of tubular dysfunction was 0.5%. Normoglycaemic glycosuria occurred in 1 (0.5%), fractional excretion of phosphate >18% in 4 (2%), and hypophosphatemia in 22 [11.1%] patients. Severe stunting was associated with increased risk of hypophosphatemia (OR 9.31 CI (1.18, 80.68) p = 0.03). Reduction in estimated glomerular filtration rate (eGFR) < 90ml/min/1.73m2 and proteinuria was evident in 35.9% and 32.8% of children, respectively. Concurrent TDF and HIV-1 protease inhibitor-based regimen was the only independent factor associated with reduction in GFR (OR 4.43 CI (1.32; 4.89) p = 0.016).

CONCLUSION

Tubular dysfunction was uncommon in Zimbabwean children on a TDF-based ART regimen. Hypophosphatemia, proteinuria and reduction in eGFR were common. Reassessing renal function using more sensitive biomarkers is needed to examine the long-term tolerance of TDF.

Contemporary issues and new challenges in chronic kidney disease amongst people living with HIV

Chronic kidney disease (CKD) is a comorbidity of major clinical significance amongst people living with HIV (PLWHIV) and is associated with significant morbidity and mortality. The prevalence of CKD is rising, despite the widespread use of antiretroviral therapy (ART) and is increasingly related to prevalent non-infectious comorbidities (NICMs) and antiretroviral toxicity. There are great disparities evident, with the highest prevalence of CKD among PLWHIV seen in the African continent. The aetiology of kidney disease amongst PLWHIV includes HIV-related diseases, such as classic HIV-associated nephropathy or immune complex disease, CKD related to NICMs and CKD from antiretroviral toxicity. CKD, once established, is often relentlessly progressive and can lead to end-stage renal disease (ESRD). Identifying patients with risk factors for CKD, and appropriate screening for the early detection of CKD are vital to improve patient outcomes. Adherence to screening guidelines is variable, and often poor. The progression of CKD may be slowed with certain clinical interventions; however, data derived from studies involving PLWHIV with CKD are sparse and this represent an important area for future research. The control of blood pressure using angiotensin converting enzyme inhibitors and angiotensin receptor blockers, in particular, in the setting of proteinuria, likely slows the progression of CKD among PLWHIV. The cohort of PLWHIV is facing new challenges in regards to polypharmacy, drug-drug interactions and adverse drug reactions. The potential nephrotoxicity of ART is important, particularly as cumulative ART exposure increases as the cohort of PLWHIV ages. The number of PLWHIV with ESRD is increasing. PLWHIV should not be denied access to renal replacement therapy, either dialysis or kidney transplantation, based on their HIV status. Kidney transplantation amongst PLWHIV is successful and associated with an improved prognosis compared to remaining on dialysis. As the cohort of PLWHIV ages, comorbidity increases and CKD becomes more prevalent; models of care need to evolve to meet the new and changing chronic healthcare needs of these patients.

Determinants of Risk Factors for Renal Impairment among HIV-Infected Patients Treated with Tenofovir Disoproxil Fumarate-Based Antiretroviral Regimen in Southern Vietnam

Background

The situation of renal impairment among HIV-infected patients treated with TDF-based antiretroviral (ARV) regimen greater than 3 years is little known when TDF use has been promptly increasing in Vietnam.

Methods

We analyse demographic and clinical data from a cross-sectional survey of 400 HIV-infected patients aged ≥18 years, who were treatment-naive or switched TDF regimen within over 3 years between November 2018 and March 2019. Serological tests for serum creatinine, ALT, and AST were performed. Renal impairment was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². Multivariate regression analyses were used to explore the risk factors associated with renal impairment.

Results

At the baseline, 7.8% of respondents had estimated glomerular filtration rate (eGFR) of 30-59 mL/min/1.73 m² and 0.8% had eGFR of 15-29 mL/min/1.73 m², out of 34 (8.5%) of participants who had renal impairment. Multivariate analysis showed that participants who had preexposure to isoniazid (adjusted PR [aPR] = 0.35 Cl: 0.14-0.91) compared with nonexposure to isoniazid who had a BMI from 18.5 up to 25 kg/m² (aPR = 0.31 Cl: 0.15-0.62) compared with BMI below 18.5 kg/m² were less likely to suffer from renal impairment. Patients aged greater than 60 years (aPR = 26.75, 95% Cl: 3.38-211.62) compared with those aged 20-29 years were more likely to have increased risk of renal impairment.

Conclusion

Our findings underscore the need for longitudinal studies to assess the influence of TDF on maintaining the low prevalence of renal impairment among HIV-infected patients in Vietnam.

Proteomics analysis of blood plasma in HIV-infected patients with chronic kidney disease

BACKGROUND

Patients treated for human immunodeficiency virus (HIV) infection are prone to developing chronic kidney disease (CKD). Current methods used in assessing kidney function suffer inaccuracy in HIV-infected patients. This study aims to identify biomarkers that could complement existing methods of kidney assessment among HIV-infected subjects.

METHODS

Plasma protein profiling was performed for HIV patients with CKD presented with negative/trace proteinuria (non-proteinuric) (n = 8) and their matched non-CKD controls, using two-dimensional gel electrophoresis (2DE); selected protein candidates were identified using mass spectrometry. Subsequently, altered plasma abundance of protein candidates were verified using Western blotting in HIV-infected subjects with non-proteinuric CKD (n = 8), proteinuric CKD (n = 5), and their matched non-CKD controls, as well as in HIV-uninfected subjects with impaired kidney function (n = 3) and their matched controls.

RESULTS

Analysis of 2DE found significantly altered abundance of five protein candidates between HIV-infected patients with non-proteinuric CKD and without CKD: alpha-1-microglobulin (A1M), serum albumin (ALB), zinc-alpha-2-glycoprotein (AZGP1), haptoglobin (HP), and retinol binding protein (RBP4). Western blotting showed an increased abundance of A1M and HP in HIV-infected patients with non-proteinuric CKD compared to their non-CKD controls, whereas A1M, AZGP1, and RBP4 were significantly increased in HIV-infected patients with proteinuric CKD compared to their non-CKD controls. Such pattern was not found in HIV-uninfected subjects with impaired kidney function.

CONCLUSION

The data suggests four proteins that may be used as biomarkers of CKD in HIV-infected patients. Further validation in a larger cohort of HIV-infected patients is necessary for assessing the clinical use of these proposed biomarkers for CKD.

Diabetes negatively impacts the ten-year survival rates of people living with HIV

People living with HIV (PLWH) are dying of non-AIDS associated conditions, including type 2 diabetes and chronic kidney disease (CKD), but the impact of diabetes and CKD on HIV survival rates is unknown. The purpose of this retrospective longitudinal study was to investigate the impact of diabetes and CKD on the survival rates of PLWH, using a secondary analysis of data from the Centers for AIDS Research Network of Integrated Clinical Systems ( N = 10,043 PLWH). The sample was divided into three comorbidity groups: HIV alone, HIV with diabetes, and HIV with diabetes and CKD. Kaplan–Meier analysis was used to examine survival rates; Cox regression was used to assess relationships between variables. Overall mean survival time was 19.7 years (95% CI, 19.57–19.8). For HIV alone ( n = 8266), the mortality rate was 3.6%; for HIV with diabetes ( n = 1720), mortality was almost three times higher (12.0%); and for HIV with diabetes and CKD ( n = 57), survival was less than three times higher (36.8%) than for HIV alone. Knowing that diabetes mellitus decreases survival rates, healthcare providers need to halt or delay the onset of type 2 diabetes by more aggressively assessing for prediabetes and treating it.

Epidemiological, clinical, and laboratory factors associated with chronic kidney disease in Mexican HIV-infected patients

AIM

To determine the prevalence of chronic kidney disease (CKD) and the epidemiological, clinical, and laboratory factors associated with CKD in Mexican HIV-infected patients.

METHODS

Cross-sectional study. We included 274 patients with HIV/AIDS. CKD was defined by the estimated glomerular filtration rate (eGFR < 60 mL/min/1.73 m2 assessed by CKD-EPI) and albuminuria criteria from KDIGO guidelines. Clinical, epidemiological, and laboratory characteristics were compared between patients with and without CKD. The factors associated with CKD were assessed by logistic regression analysis.

RESULTS

The mean age was 41±11 years, and 72.3% of the patients were men. The global prevalence of CKD was 11.7% (n = 32); 7.2% (n = 20) were defined by eGFR criterion; 7.6% (n = 21), by the albuminuria criterion; and 3.2% (n = 9), by both CKD criteria. The most frequently observed stages of CKD were KDIGO G3A1 stage with 4.7% (n = 13), KDIGO G1A2 stage with 3.6% (n = 10) and KDIGO G3A2 stage with 1.7% (n = 5). The factors associated with CKD were use of abacavir/lamivudine (OR 3.2; 95% CI 1.1-8.9; p = 0.03), a CD4 lymphocyte count < 400 cells/µL (OR 2.6; 95% 1.03-6.4, p = 0.04), age (OR 1.1; 95% CI 1.04-1.2, p = 0.001) and albuminuria (OR 19.98; 95% CI: 5.5-72.2; p < 0.001).

CONCLUSIONS

CKD was a frequent complication in HIV-infected patients. These findings confirm the importance of screening and the early detection of CKD, as well as the importance of identifying and treating traditional and non-traditional risk factors associated with CKD.

Incidence of cardiovascular diseases in a nationwide HIV/AIDS patient cohort in Taiwan from 2000 to 2014

The purpose of the study was to determine the incidence of cardiovascular disease (CVD) among people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (PLWHA) in Taiwan. PLWHA were identified from the Taiwan Centers for Disease Control HIV Surveillance System between 2000 and 2014. To examine the effect of active antiretroviral therapy (HAART) on CVD incidence, incidence densities and standardised incidence rates (SIRs) of CVD were calculated after stratifying PLWHA by HAART. Of 26 272 PLWHA (mean age, 32.3 years) identified, 73.4% received HAART. Compared with general population, SIRs (95% confidence interval) were higher for incident coronary artery disease (1.11 (1.04-1.19)), percutaneous coronary intervention (1.32 (1.18-1.47)), coronary artery bypass surgery (1.47 (1.29-1.66)), sudden cardiac death (3.01 (2.39-3.73)), heart failure (1.50 (1.31-1.70)) and chronic kidney disease (1.95 (1.81-2.10)), but was lower for incident atrial fibrillation (0.53 (0.37-0.73)). Considering the effect of HAART on incident CVD, the SIRs for all-cause, ischaemic and haemorrhagic stroke were higher in PLWHA who did not receive HAART, but were lower in PLWHA who received HAART. PLWHA had higher risks of incident coronary artery disease, percutaneous coronary intervention, coronary artery bypass surgery, sudden cardiac death, heart failure and chronic kidney disease. HAART reduces risks of incident CVD in PLWHA.

Clinical and genetic factors associated with kidney tubular dysfunction in a real-life single centre cohort of HIV-positive patients

Background

Tenofovir (TDF) is one of the most widely used antiretroviral drug. Despite the high degree of tolerability a small percentage of patients experienced alteration in tubular function during TDF use. Intracellular TDF disposition is regulated by ATP-binding cassette (ABC) drug efflux transporters and, a reduced transport activity may be implicated in accumulation of TDF into the cells. The aim of our study was to assess the major determinants of TDF associated tubular dysfunction (KTD) in a real-life setting including the usefulness of single-nucleotide polymorphisms (SNPs) mapping into ABCC2, ABCC4 and ABCC10 genes.

Methods

We retrospectively analyzed all HIV positive patients who were followed at the Infectious Diseases Unit, DIBIC Luigi Sacco, University of Milan from April 2013 to June 2016. All patients treated with TDF who underwent a genotypization for the functional variants mapping in ABCC2 rs717620 (−24 C > T), ABCC4 rs1751034 (3463 A > G) and ABCC10 rs2125739 (T > C) were evaluated. KTD was defined as the presence of urine phosphate wasting and/or proteinuria at 24 h urine analysis.

Results

One hundred fifty-eight patients were genotyped, of which 42 (26.6%) experienced signs of KTD. No statistical significant differences were observed among patients with or without KTD regarding age, gender, ethnicity and comorbidities (hypertension and diabetes). The percentage of patients with KTD was higher among those with “GG” genotype at rs1751034 of ABCC4 compared to patients without KTD [6 (14.3%) vs 4 (3.5%), p = 0.01]. No statistical significant differences were observed regarding the distribution of ABCC2 and ABCC10 SNPs. Carriers of “G” allele in homozygous status at rs1751034 of ABCC4 showed a significant association with KTD (Odds Ratio 4.67, 95% CI 1.25–17.46, p = 0.02) in bivariate analysis, but this association was lost in multivariable analysis. A significant association between bone diseases and KTD was observed (Odds Ratio 3.178, 95%CI 1.529–6.603, p = 0.002).

Conclusions

According to our results ABCC4 rs1751034 could be a genetic determinant of KTD; however validation studies are needed for therapy personalization. Noteworthy, a strong association between bone disease and KTD was also observed.

Screening and management practices for renal disease in the HIV-positive patient population of an inner metropolitan sexual health service

Renal disease is an important and commonly encountered co-morbidity in HIV infection. Despite this, few data are available concerning renal disease in this patient group. A retrospective review was conducted of all HIV-positive patients of an inner metropolitan sexual health service who attended from 1 August 2013 to 31 July 2014 for HIV management. One hundred eighty-eight HIV-positive patients attended the clinic during the study period. The majority were male (96%), Caucasian (70%) and 30-39 years of age (37%). There was a high prevalence of renal risk factors in the population, including potentially nephrotoxic antiretroviral therapy (61%), smoking (38%), hypertension (12%), dyslipidemia (11%) and hepatitis C co-infection (7%). In the previous year, measurements of estimated glomerular filtration rate were performed in all patients, but measurements of lipid profiles, urinary protein and serum phosphate were performed within the last year in only 48%, 33% and 30% of patients, respectively. These are the first comprehensive data regarding renal disease, associated risk factors and screening and management practices in the HIV-positive patient population of a specialized sexual health service in Australia. This patient population demonstrates a particularly high prevalence of risk factors for renal disease. Despite this, screening investigations were not performed as recommended. This represents a potential area to improve patient care.

Frequent injection cocaine use increases the risk of renal impairment among hepatitis C and HIV coinfected patients

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Objective:

To examine the association between injection cocaine use, hepatitis C virus (HCV) infection, and chronic renal impairment (CRI).

Design:

Prospective observational cohort study of HIV–HCV coinfected patients.

Methods:

Data from 1129 participants in the Canadian Co-Infection Cohort with baseline and follow-up serum creatinine measurements between 2003 and 2014 were analyzed. Prevalent and incident cohorts were created to examine the association between self-reported past, current, and cumulative cocaine use and chronic HCV with CRI. CRI was defined as an estimated glomerular filtration rate below 70 ml/min per 1.73 m². Multivariate logistic regression was used to calculate odds ratios, and discrete-time proportional-hazards models were used to calculate hazard ratios for cocaine use, in the two respective cohorts, adjusted for HCV RNA and important demographic, HIV disease stage, and comorbidity confounders.

Results:

Eighty-seven participants (8%) had prevalent CRI. Past injection cocaine use was associated with a two-fold greater risk of prevalent CRI [odds ratio 2.03, 95% confidence interval (CI) 0.96, 4.32]. During follow-up, 126 of 1061 participants (12%) developed incident CRI (31 per 1000 person-years). Compared to nonusers, heavy (≥ 3 days/week) and frequent injection cocaine users (≥75% of follow-up time) experienced more rapid progression to CRI (hazard ratio 2.65, 95% CI 1.35, 5.21; and hazard ratio 1.82, 95% CI 1.07, 3.07, respectively). There was no association between chronic HCV and CRI in either cohort.

Conclusion:

After accounting for HCV RNA, frequent and cumulative injection cocaine abuse was associated with CRI progression and should be taken into consideration when evaluating impaired renal function in HIV–HCV coinfection.

Water, electrolytes, and acid-base alterations in human immunodeficiency virus infected patients

The clinical spectrum of human immunodeficiency virus (HIV) infection associated disease has changed significantly over the past decade, mainly due to the wide availability and improvement of combination antiretroviral therapy regiments. Serious complications associated with profound immunodeficiency are nowadays fortunately rare in patients with adequate access to care and treatment. However, HIV infected patients, and particularly those with acquired immune deficiency syndrome, are predisposed to a host of different water, electrolyte, and acid-base disorders (sometimes with opposite characteristics), since they have a modified renal physiology (reduced free water clearance, and relatively increased fractional excretion of calcium and magnesium) and they are also exposed to infectious, inflammatory, endocrinological, oncological variables which promote clinical conditions (such as fever, tachypnea, vomiting, diarrhea, polyuria, and delirium), and may require a variety of medical interventions (antiviral medication, antibiotics, antineoplastic agents), whose combination predispose them to undermine their homeostatic capability. As many of these disturbances may remain clinically silent until reaching an advanced condition, high awareness is advisable, particularly in patients with late diagnosis, concomitant inflammatory conditions and opportunistic diseases. These disorders contribute to both morbidity and mortality in HIV infected patients.

Urinary biomarkers of kidney diseases in HIV-infected children

A significant number of children infected with the human immunodeficiency virus 1 (HIV-1) virus all over the world are at risk of developing renal diseases that could have a significant impact on their treatment and quality of life. It is necessary to identify children undergoing the early stages of these renal diseases, as well as the potential renal toxicity that could be caused by antiretroviral drugs, in order to prevent the development of cardiovascular complications and chronic renal failure. This article describes the most common renal diseases seen in HIV-infected children, as well as the value and limitations of the clinical markers that are currently being used to monitor their renal function and histological damage in a noninvasive manner. In addition, we discuss the progress made during the last 10 years in the discovery and validation of new renal biomarkers for HIV-infected children and young adults. Although significant progress has been made during the early phases of the biomarkers discovery, more work remains to be done to validate the new biomarkers in a large number of patients. The future looks promising, however, the new knowledge needs to be integrated and validated in the context of the clinical environment where these children are living.

Renal transplantation in human immunodeficiency virus (HIV)-positive children

Renal transplantation is being performed in adult human immunodeficiency virus (HIV)-positive patients and increasingly in paediatric patients as well. A multidisciplinary team involving an infectious disease professional is required to assist with HIV viral-load monitoring and in choosing the most appropriate highly active antiretroviral therapy (HAART). Drug interactions complicate immunosuppressant therapy and require careful management. The acute rejection rates appear to be similar in adults to those in noninfective transplant recipients. Induction with basiliximab and calcineurin-based immunosuppression appears to be safe and effective in these recipients. Prophylaxis is advised for a variety of infections and may need life-long administration, especially in children. Organ shortage remains a significant problem, and kidneys from deceased HIV-positive donors have been used successfully in a small study population. Overall, with careful planning and close follow-up, successful renal transplantation for paediatric HIV-infected recipients is possible.

The role of drug transporters in the kidney: lessons from tenofovir

Tenofovir disoproxil fumarate, the prodrug of nucleotide reverse transcriptase inhibitor tenofovir, shows high efficacy and relatively low toxicity in HIV patients. However, long-term kidney toxicity is now acknowledged as a modest but significant risk for tenofovir-containing regimens, and continuous use of tenofovir in HIV therapy is currently under question by practitioners and researchers. Co-morbidities (hepatitis C, diabetes), low body weight, older age, concomitant administration of potentially nephrotoxic drugs, low CD4 count, and duration of therapy are all risk factors associated with tenofovir-associated tubular dysfunction. Tenofovir is predominantly eliminated via the proximal tubules of the kidney, therefore drug transporters expressed in renal proximal tubule cells are believed to influence tenofovir plasma concentration and toxicity in the kidney. We review here the current evidence that the actions, pharmacogenetics, and drug interactions of drug transporters are relevant factors for tenofovir-associated tubular dysfunction. The use of creatinine and novel biomarkers for kidney damage, and the role that drug transporters play in biomarker disposition, are discussed. The lessons learnt from investigating the role of transporters in tenofovir kidney elimination and toxicity can be utilized for future drug development and clinical management programs.

Screening and management of renal disease in human immunodeficiency virus-infected patients in Australia

BACKGROUND

Renal disease has become one of the most important comorbidities observed in the human immunodeficiency virus (HIV)-infected patient cohort. Data are lacking on the current screening and management of renal disease in patients with HIV. We evaluated HIV-infected Australian adults in primary care to determine current practices.

METHODS

This prospective, multicentre observational study included two rounds of data collection; the first was followed by an educational programme. Outcomes included screening for renal disease; management of risk factors for kidney disease and other comorbidities associated with renal disease.

RESULTS

Fifty-three general practitioners participated with 733 patients enrolled. Most were male (94%); almost 40% were 41-50 years of age, and 6% and 84% were receiving antiretroviral therapy. Comorbidities were common; 19% had hypertension, 5% were diabetic, 32% were dyslipidaemic, and 40% were smokers. Estimated glomerular filtration rate was commonly measured in both rounds of data collection (96% vs 95%). Proteinuria was assessed less frequently; this improved after education (48% vs 71%). Almost 10% of patients tested had proteinuria on urinalysis. Of the 45 patients (6%) with renal impairment (estimated glomerular filtration rate <60 mL/min), none was referred for assessment by a renal specialist.

CONCLUSIONS

This large observational study provides important information on renal disease in HIV-infected patients, an area with a paucity of clinical data. Current screening and management practices fall short of suggested guidelines. Failure to refer patients to specialists is a major deficiency. Improvements with education suggest the need to promote awareness of guidelines in primary care doctors.

Prevalence and risk factors for chronic kidney disease among HIV-infected antiretroviral therapy-naïve patients in mainland China: a multicenter cross-sectional study

AIM

The aim of the study was to evaluate the prevalence and risk factors of chronic kidney disease (CKD) among HIV-infected antiretroviral therapy (ART)-naïve patients in Mainland China.

METHODS

In this multicenter cross-sectional study, glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease (MDRD) equation. CKD was defined as GFRMDRD  < 60 mL/min per 1.73 m(2) and/or isolated proteinuria (≥1 + on urine dipstick) that persisted at month 3 after the baseline assessment. Risk factors associated with CKD were examined using univariate analysis and multivariate logistic regression analysis.

RESULTS

In total, 538 HIV-infected ART-naïve patients were included in this study. There were 399 male and 139 female patients. The mean age was 36.5 ± 10.0 years. The prevalence of hypertension, glycometabolism abnormities, and CKD were 3.2%, 3.0%, and 16.1%, respectively. Thirteen (2.4%) patients had estimated GFR (eGFR) < 60 mL/min per 1.73 m(2), while 73 (13.7%) patients had proteinuria. Using univariate analysis, CKD was found to be significantly (P < 0.05) associated with age, hypertension, HCV co-infection, and plasma HIV-1 viral load ≥ 100 000 copies/mL. In the multivariate logistic regression model, older age (increased by an interval of 10 years; P = 0.002), HCV co-infection (P = 0.039), and plasma HIV-1 viral load ≥ 100 000 copies/mL (P = 0.011) were significantly associated with CKD.

CONCLUSION

The incidence of CKD is high in Chinese HIV-infected ART-naïve patients. Traditional risk factors for renal disease, such as advancing age, HCV co-infection, and higher plasma viral load were correlated with CKD in the present patient samples.

Related factors to atazanavir plasma levels in a cohort of HIV positive individuals with undetectable viral load

Objective

To evaluate the factors associated with plasma concentrations of atazanavir (ATV) in a cohort of well-controlled HIV infected subjects (undetectable viremia).

Design

Cross-sectional study where 69 subjects were consecutively enrolled between April and November, 2011.

Methods

Patients had to be on atazanavir for at least six months, undetectable viral load for a period equal to or longer than 12 months, T CD4+ lymphocyte count higher than 200 cells/mm³, and aged between 18 years and 70 years old. Exclusion criteria were pregnancy, any neurologic disease, active opportunistic disease, hepatitis or cancer. Atazanavir plasma levels were measured by ultra-performance liquid chromatography.

Results and discussion

Overall, 54 patients (mean age of 47 years and 50% women) were included in the analysis. Those without ritonavir (unboosted atazanavir) had statistically lower plasma concentrations than those with ritonavir boosted atazanavir (p = 0.001) and total and indirect bilirubin were statistically associated with plasma concentration of atazanavir (r = 0.32 and r = 0.33 respectively; p < 0.05 in both cases). No statistical association was found among gender, ethnicity, age, weight, body mass index (BMI), lipid profile, and the plasma concentration of atazanavir.

Conclusion

In summary, as expected, concomitant ritonavir use was the only factor associated with atazanavir plasma levels. Prospective studies with a larger sample size might help to observe an association of atazanavir concentrations to other characteristics such as body weight, since the p-value showed to be close to significance (p = 0.068).

The significance of antiretroviral-associated acute kidney injury in a cohort of ambulatory human immunodeficiency virus-infected patients

BACKGROUND

To determine the incidence and significance of acute kidney injury (AKI) after initiating highly active antiretroviral therapy (HAART).

METHODS

A prospective cohort study of 271 consecutively treated HIV-infected patients, initiating first (75) or sequential HAART (196) from January 2008 to June 2011. AKI was diagnosed according to the Risk, Injury, Failure, Loss of kidney function, End-stage renal disease (RIFLE)/Acute Kidney Injury Network (AKIN) criteria, and the risk of progression to chronic kidney disease (CKD) was evaluated.

RESULTS

A greater estimated glomerular filtration rate (eGFR) decrease after 1 year was observed for patients initiating a tenofovir disoproxil fumarate (TDF)-based regimen (-6.45 versus +0.98 mL/min/1.73 m(2) when compared with patients without TDF; P < 0.01), both in the case of the first (-8.5 versus -2.27; P = 0.04) or successive regimens (-5.3 versus + 1.18 mL/min/1.73 m(2); P < 0.01). AKI, as defined, was observed in 10% (28 cases, 6.98 episodes/100 patients-year), mostly stage I (27 cases), in a median time of 6 (3-16.5) months. Four cases (14%), having a worse baseline renal function progressed to CKD, whereas four recovered completely. In the multivariate analysis, AKI was associated with the concomitant use of cotrimoxazole prophylaxis and to low CD4+ count. CKD was diagnosed in 2% (six cases) of patients. Therefore, the overall rate of HAART-associated renal disorders was 11% (30 cases, 7.46 episodes/100 patients-year (95% confidence interval, 6.09-8.83).

CONCLUSIONS

The initiation of a tenofovir-based regimen is followed by a significant decline in eGFR, although it could be misinterpreted by the concomitant use of cotrimoxazole. A substantial proportion of patients develop AKI, but only a minority progress to CKD. Patients initiating HAART and developing AKI should be carefully monitored for progression of renal disease.

Renal dysfunction in the setting of HIV/AIDS

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

A randomized, pilot trial to evaluate glomerular filtration rate by creatinine or cystatin C in naive HIV-infected patients after tenofovir/emtricitabine in combination with atazanavir/ritonavir or efavirenz

BACKGROUND

Glomerular filtration rate (GFR) estimated by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on creatinine or cystatine C may be more accurate methods especially in patients without chronic kidney disease. There is lack of data on GFR estimated by these methods in patients on highly active antiretroviral therapy.

METHODS

Antiretroviral-naive HIV-infected patients were randomized to tenofovir/emtricitabine in association with atazanavir/ritonavir (ATV/r) or efavirenz (EFV) Patients had to have an actual creatinine clearance >50 mL/minute (24-hour urine collection) and were followed for 48 weeks.

RESULTS

Ninety-one patients (48 ATV/r, 43 EFV) were recruited. Using the CKD-EPI creatinine formula, there was a significant decrease in GFR up to week 48 in patients receiving ATV/r (4.9 mL/minute/m(2), P = 0.02) compared with a not statistically significant increment in patients prescribed EFV. Using the cystatin C-based equation, we found greater decrease in GFR in both arms, although, in the EFV arm, the decrease was not statistically significant (5.8 mL/minute/m(2), P = 0.92). At multivariable analysis, ATV/r was a significant predictor of greater decrease in estimated glomerular filtration rate (eGFR) (P = 0.0046) only with CKD-EPI creatinine.

CONCLUSIONS

ATV/r plus tenofovir caused greater GFR decreases compared with EFV. The evaluation of eGFR by cystatin C confirmed this result, but this method seemed to be more stringent, probably precluding the possibility to detect a significant difference in the pattern of eGFR evolution between the two arms over time. More studies are needed to understand the clinical relevance of these alterations and whether cystatin C is a more appropriate method for monitoring GFR in clinical practice.

[Risk factors related to renal disorders in HIV-1 infected patients]

INTRODUCTION

Renal disease has emerged as one of the primary comorbid conditions affecting HIV-infected patients, mainly because antiretroviral therapy has improved survival. This study aimed to detect risk factors possibly associated with altered renal function in HIV-infected patients.

METHODS

A cross-sectional study was conducted involving 254 HIV-infected patients attending an outpatient clinic at Santa Casa de Vitoria< They were interviewed and blood samples were collected for CD4 cell counts, HIV-1 viral load, glucose, lipids and creatinine measurements. Urine protein was evaluated in the first voiding urine sample. Glomerular filtration was estimated by simplified modified diet in renal disease (MDRD) and Cockcroft-Gault formulas.

RESULTS

One hundred and three (40.6%) patients presented some urinary abnormality, and proteinuria was the most common finding (46; 18.1% patients). Twenty-five (9.8%) patients showed estimated glomerular filtration below 60 ml/min/1.73 m² by MDRD. Multivariate logistic regression showed that low glomerular filtration was positively correlated with black race [OR 9.6 (IC95% 1.28-23.80)], arterial hypertension [OR 3.3 (IC95% 1.28-23.81)], age over fifty-one years-old [OR 3.3 (IC95%1.11-9.90)], proteinuria [OR 5.2 {IC95% 1.67-16.25}]; hematuria [OR 3.2 (1.12-9.29)] and negatively correlated with patients using zidovudine [OR 0.2 (0.04-0.78)].

CONCLUSIONS

Traditional risk factors for renal disease, such as black race, arterial hypertension and advancing age were correlated with low estimated glomerular filtration in the present patient sample.

Comparative analysis of the new chronic kidney disease epidemiology collaboration and the modification of diet in renal disease equations for estimation of glomerular filtration rate in HIV type 1-infected subjects

Recently, a new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula was presented as a better alternative to the modification of diet in renal disease (MDRD) formula for GFR estimation (eGFR) in patients with relatively well-preserved kidney function. The main objective of our study was to compare the eGFR results arrived by the new CKD-EPI to the older MDRD equation in antiretroviral (ARV)-naive and ARV-treated HIV-1-infected patients. The study was performed in 287 adult HIV-1-infected patients and was an evaluation comparing eGFR results based on age, gender, race, and serum creatinine. The biggest difference in estimated glomerular filtration rate (eGFR) measured by the two formulas was seen in ARV-naive men with well-preserved kidney function (p = 0.001). Moreover, we found a significant negative correlation between mean difference in eGFR measured by the two equations and the age of the studied subjects (r = -0.37, p < 0.001). No correlation was observed between mean difference in eGFR and HIV viral load (r = -0.15, p = 0.2). Independent of the equation used, a significant decrease of eGFR in ARV-treated in comparison to ARV-untreated HIV-1-infected patients was seen (p < 0.001). In conclusion, in HIV-1-infected subjects, especially in ARV-naive men with well-preserved kidney function, eGFR measured by MDRD and CKD-EPI formulas varies strongly following the method used. Such discrepancies may be important in everyday clinical practice and must be confirmed by additional studies using GFR measured with a reference method.

Renal dysfunction among HIV-infected patients starting antiretroviral therapy

OBJECTIVE

HIV-related renal dysfunction is associated with high mortality. Data on the prevalence of renal dysfunction among HIV-infected outpatients starting antiretroviral therapy (ART) in sub-Saharan Africa are limited. Recent recommendations to include the nephrotoxic drug tenofovir in first-line ART regimens make clarification of this issue urgent.

METHODS

We screened for renal dysfunction by measuring serum creatinine, proteinuria, and microalbuminuria in HIV-positive outpatients initiating ART in Mwanza, Tanzania. We excluded patients with pre-existing renal disease, hypertension, diabetes, or hepatitis C virus co-infection. Estimated glomerular filtration rates (eGFRs) were calculated by Cockroft-Gault and Modification of Diet in Renal Disease equations.

RESULTS

Only 129 (36%) of 355 enrolled patients had normal eGFRs (grade 0 or 1) above 90 ml/min per 1.73 m. Grade 2 renal dysfunction (eGFR between 60 and 89 ml/min per 1.73 m) was present in 137 patients (38.6%), and 87 patients (25%) had grade 3 dysfunction (eGFR between 30 and 59 ml/min per 1.73 m). Microalbuminuria and proteinuria were detected in 72 and 36% of patients, respectively. Factors predictive of renal dysfunction in multivariate analysis included female sex [odds ratio (OR) 3.0, 95% confidence interval (1.8-5.1), P < 0.0001], BMI less than 18.5 [OR 2.3 (1.3-4.1), P = 0.004], CD4 T-cell count below 200 cells/μl [OR 2.3 (1.1-4.8), P = 0.04], and WHO clinical stage II or above [OR 1.6 (1.2-2.3), P = 0.001].

CONCLUSION

Renal dysfunction was highly prevalent in this population of HIV-positive outpatients initiating first ART in Tanzania. This highlights the critical and underappreciated need to monitor renal function in HIV-positive patients in sub-Saharan Africa, particularly given the increasing use of tenofovir in first-line ART.

The search for host genetic factors of HIV/AIDS pathogenesis in the post-genome era: progress to date and new avenues for discovery

Though pursuit of host genetic factors that influence the pathogenesis of HIV began over two decades ago, progress has been slow. Initial genome-level searches for variations associated with HIV-related traits have yielded interesting candidates, but less in the way of novel pathways to be exploited for therapeutic targets. More recent genome-wide association studies (GWAS) that include different phenotypes, novel designs, and that have examined different population characteristics suggest novel targets and affirm the utility of additional searches. Recent findings from these GWAS are reviewed, new directions for research are identified, and the promise of systems biology to yield novel insights is discussed.