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

Prevalence and Risk Factors for Renal Insufficiency among Adults Living with HIV in Tanzania: Results from a Cross-Sectional Study in 2020-2021

With improved survival, adults living with HIV (ALHIV) are increasingly likely to experience age-related and HIV-related comorbidities, including renal insufficiency. Other risk factors for renal insufficiency (high blood pressure (BP), obesity, diabetes, and dyslipidemia) are also growing more common among ALHIV. To determine the prevalence of renal insufficiency (defined as an eGFR < 60 mL/min/1.73 m2) and factors associated with reduced eGFR, we conducted a cross-sectional study at six HIV clinics in Dar-es-Salaam, Tanzania. We applied multivariable (MV) ordinal logistic regression models to identify factors associated with reduced eGFR and examined the interaction of age with BP levels. Among the 450 ALHIV on ART analyzed [26% males; median age 43 (IQR: 18-72) years; 89% on tenofovir-containing ART; 88% HIV viral load ≤50 copies/mL], 34 (7.5%) had renal insufficiency. Prevalence was higher among males (12%) vs. females (6%), p = 0.03; ALHIV ≥50 (21%) vs. <50 years (2.5%), p < 0.001; those with high [≥130/80 mmHg (15%)] vs. normal [<120/80 mmHg (4%)] BP, p < 0.01 and those with dyslipidemia (10%) vs. those without (4.5%), p < 0.03. After adjusting for covariates, age (in years) was the only covariate with a statistically significant association with reduced eGFR (OR = 1.09 (1.07-1.12), p < 0.001). No significant interaction between age and BP was found. Interventions to increase routine screening for renal insufficiency, especially among older ALHIV, and improve BP control are critical to reducing kidney disease-related morbidity and mortality.

Influence of HIV/AIDS Infection on Immunological and Nutritional Status in Adults and Older Adults: A Cross-Sectional Study in Kingdom of Bahrain

Background and Objectives: HIV infection is a global public health problem that can lead to the progression of AIDS. Nutritional status and biochemical markers can significantly contribute to the progression of AIDS in HIV/AIDS patients. The main objective of this study is to examine the association between nutritional and biochemical markers as well as BMI in HIV/AIDS patients in the kingdom of Bahrain. Methods: A retrospective cohort study, including 300 patients (248 males and 52 females) with HIV/AIDS in Bahrain, was carried out. Various biochemical markers were collected from patients' medical records, including CD4+ T cell count, albumin, Hb, HCT, MCV, WBCs, and creatinine. A semi-structured questionnaire using a standardized food frequency questionnaire (FFQ) was used, from which total energy and total macronutrients were calculated. Results: The mean BMI of the participants was 27.20 kg/m2, and none of the participants had a BMI lower than 18.5 kg/m2 (underweight). The majority of patients' dietary intake of macronutrients and total calorie intake were either within or above the recommended RDA levels. The results also showed that all of the mean values of the nutritional and biochemical markers (CD4+ T cell count, albumin, Hb, HCT, MCV, WBCs, and creatinine) were within the normal reference ranges. A significant positive correlation between CD4+ T cell count, Hb, HCT, and albumin at the <0.05 level was found. There was no significant correlation between CD4+ T cell count and MCV, WBCs, and creatinine. A positive significant correlation was found between BMI, CD4+ T cell count, and WBCs at the <0.01 level. Conclusion: The BMI values were significantly correlated with the biochemical markers of AIDS progression. The dietary patterns of the participants were undiversified, with a high prevalence of obesity and overweight. Malnutrition among this study population was not present.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

APOL1 Renal Risk Variants and Kidney Function in HIV-1–Infected People From Sub-Saharan Africa

Introduction

APOL1 G1 and G2 alleles have been associated with kidney-related outcomes in people living with HIV (PLHIV) of Black African origin. No APOL1-related kidney risk data have yet been reported in PLHIV in West Africa, where high APOL1 allele frequencies have been observed.

Methods

We collected clinical data from PLHIV followed in Burkina Faso (N = 413) and in the ANRS-12169/2LADY trial (Cameroon, Senegal, Burkina Faso, N = 369). APOL1 G1 and G2 risk variants were genotyped using TaqMan assays, and APOL1 high-risk (HR) genotype was defined by the carriage of 2 risk alleles.

Results

In West Africa (Burkina Faso and Senegal), the G1 and G2 allele frequencies were 13.3% and 10.7%, respectively. In Cameroon (Central Africa), G1 and G2 frequencies were 8.7% and 8.9%, respectively. APOL1 HR prevalence was 4.9% in West Africa and 3.4% in Cameroon. We found no direct association between APOL1 HR and estimated glomerular filtration rate (eGFR) change over time. Nevertheless, among the 2LADY cohort participants, those with both APOL1 HR and high baseline viral load had a faster eGFR progression (β = −3.9[−7.7 to −0.1] ml/min per 1.73 m² per year, P < 0.05) than those with low-risk (LR) genotype and low viral load.

Conclusion

Overall, the APOL1 risk allele frequencies in PLHIV were higher in the West African countries than in Cameroon, but much lower than previously reported in some Nigeria ethnic groups, which strongly advocates for further investigation in the African continent. This study suggested that the virological status could modulate the APOL1 impact on kidney function, hence reinforcing the need for early therapeutic interventions.

Construction and validation of a prognostic nomogram for predicting the survival of HIV/AIDS adults who received antiretroviral therapy: a cohort between 2003 and 2019 in Nanjing

BACKGROUND

Great achievements have been achieved by free antiretroviral therapy (ART). A rapid and accurate prediction of survival in people living with HIV/AIDS (PLHIV) is needed for effective management. We aimed to establish an effective prognostic model to forecast the survival of PLHIV after ART.

METHODS

The participants were enrolled from a follow-up cohort over 2003-2019 in Nanjing AIDS Prevention and Control Information System. A nested case-control study was employed with HIV-related death, and a propensity-score matching (PSM) approach was applied in a ratio of 1:4 to allocate the patients. Univariable and multivariable Cox proportional hazards analyses were performed based on the training set to determine the risk factors. The discrimination was qualified using the area under the curve (AUC) and concordance index (C-Index). The nomogram was calibrated using the calibration curve. The clinical benefit of prognostic nomogram was assessed by decision curve analysis (DCA).

RESULTS

Predictive factors including CD4 cell count (CD4), body mass index (BMI) and hemoglobin (HB) were determined and incorporated into the nomogram. In the training set, AUC and C-index (95% CI) were 0.831 and 0.798 (0.758, 0.839), respectively. The validation set revealed a good discrimination with an AUC of 0.802 and a C-index (95% CI) of 0.786 (0.681, 0.892). The calibration curve also exhibited a high consistency in the predictive power (especially in the first 3 years after ART initiation) of the nomogram. Moreover, DCA demonstrated that the nomogram was clinically beneficial.

CONCLUSION

The nomogram is effective and accurate in forecasting the survival of PLHIV, and beneficial for medical workers in health administration.

Incidence Rate and Time to Occurrence of Renal Impairment and Chronic Kidney Disease among Thai HIV-infected Adults with Tenofovir Disoproxil Fumarate Use

Background:

Tenofovir disoproxil fumarate (TDF) is a major antiretroviral therapy for Thai human immunodeficiency virus (HIV) infected adults. TDF is associated with a decrease in renal function. There is limited data about the use of TDF with the incidence and time to renal impairment and chronic kidney disease (CKD) in Thai HIV-infected adults.

Objectives:

To study the association of TDF with the incidence rate and duration of renal impairment and CKD in Thai patients.

Methods:

A retrospective cohort study in Thai naïve HIV-infected adults was conducted to compare the incidence rate and time to renal impairment and CKD in TDF and non-TDF groups. The incidence rate was analyzed by person-time. Time to renal impairment and CKD were analyzed by Kaplan-Meier curves and log-rank tests.

Results:

A total of 1,400 patients were enrolled. The incidence rates of renal impairment in TDF and non-TDF groups were 27.66/1,000 and 5.54/1,000 person-years. The rate ratio was 4.99 (95% confidence interval [CI] 2.66–9.35). The incidence rates of CKD in both groups were not significantly different. Themean difference of eGFR between the TDF and non-TDF groups was 1.92 ml/min/1.73 m2 (p = 0.022). Time to onset of renal impairment between the TDF and non-TDF groups was found to differ by approximately 20 months.

Conclusion:

The incidence rate of renal impairment was about five times higher in the TDF group. A rapid decline of eGFR occurred in the first 2–3 years of treatment. Therefore, the renal function of HIV-infected patients should be monitored so that the severity of renal impairment could be evaluated and CKD could be prevented.

Apolipoprotein-1 risk variants and associated kidney phenotypes in an adult HIV cohort in Nigeria

HIV-positive adults are at risk for various kidney diseases, and apolipoprotein 1 (APOL1) high-risk genotypes increase this risk. This study aimed to determine the prevalence and ethnic distribution of APOL1 risk genotypes among a cohort of HIV-positive Nigerian adults and explore the relationship between APOL1 risk variant status with albuminuria and estimated glomerular filtration rate (eGFR). We conducted a cross-sectional study among 2 458 persons living with HIV who attended an HIV clinic in northern Nigeria and had received antiretroviral therapy for a minimum of six months. We collected two urine samples four-eight weeks apart to measure albumin excretion, and blood samples to measure eGFR and determine APOL1 genotype. The frequency of APOL1 high-risk genotype was 6.2%, which varied by ethnic group: Hausa/Fulani (2.1%), Igbo (49.1%), and Yoruba (14.5%). The prevalence of microalbuminuria (urine/albumin creatinine ratio 30- 300 mg/g) was 37%, and prevalence of macroalbuminuria (urine/albumin creatinine ratio over 300 mg/g) was 3%. The odds of microalbuminuria and macroalbuminuria were higher for participants with the APOL1 high-risk genotype compared to those carrying the low-risk genotype ([adjusted odds ratio 1.97, 95% confidence interval 1.37-2.82] and [3.96, 1.95-8.02] respectively). APOL1 high-risk genotype participants were at higher risk of having both an eGFR under 60 ml/min/1.73m2 and urine/albumin creatinine ratio over 300 mg/g (5.56, 1.57-19.69). Thus, we found a high proportion of HIV-positive, antiretroviral therapy-experienced, and largely virologically suppressed adults had microalbuminuria. Hence, although the high-risk APOL1 genotype was less prevalent than expected, it was strongly associated with some level of albuminuria.

Multidisciplinary collaborative integrated management of increasingly prominent HIV complications in the post-cART era

Objectives

With the prolonged survival time of AIDS patients, complications of various systems and organs of HIV infection are increasingly prominent. These diseases have become the major factors influencing the quality of life and prognosis of HIV‐infected persons, and multidisciplinary cooperation treatment is urgently needed.

Methods

The Chinese HIV/AIDS Clinical Trial Network has conducted a series of multicentre clinical cohort studies over the past 16 years, in which studies related to people living with HIV systemic complications. Based on the results of previous studies, this review establishes the complications of Chinese people living with HIV after long‐term cART.

Results

HIV’s direct damage to human cells, chronic abnormal inflammatory activation after HIV infection, long‐term drug side effects caused by cART and persistent reservoirs cause systemic complications in people living with HIV. We summarised the clinical characteristics of the complications of HIV infection in China from the aspects of the liver, cardiovascular, the nervous system, the kidney, bone metabolism, blood glucose, and lipid metabolism.

Conclusions

The management of the complications of HIV infection is a major link in improving the survival treatment and prognosis of patients in the future. The joint participation of doctors from different departments of general hospitals in the management of comorbidities is the main theme for future improvement of quality of life and prognosis for people living with HIV.

Prevalence of microalbuminuria and associated factors among HIV - infected ART naïve patients at Mulago hospital: a cross-sectional study in Uganda

Background

HIV infection affects multiple organs and the kidney is a common target making renal disease, one of the recognized complications. Microalbuminuria represents an early, important marker of kidney damage in several populations including HIV-infected antiretroviral therapy (ART) naïve patients. Early detection of microalbuminuria is critical to slowing down progression to chronic kidney disease (CKD) in HIV-infected patients, however, the burden of microalbuminuria in HIV-infected antiretroviral therapy (ART) naïve patients in Uganda is unclear.

Methods

A cross-sectional study was conducted in the Mulago Immune suppression syndrome (ISS) clinic among adult HIV − infected ART naïve outpatients. Data on patient demographics, medical history was collected. Physical examination was performed to assess body mass index (BMI) and hypertension. A single spot morning urine sample from each participant was analysed for microalbuminuria using spectrophotometry and colorimetry. Microalbuminuria was defined by a urine albumin creatinine ratio (UACR) 30-299 mg/g and macroalbuminuria by a UACR > 300 mg/g. To assess the factors associated with microalbuminuria, chi-square, Fisher’s exact test, quantile regression and logistic regression were used.

Results

A total of 185 adult participants were consecutively enrolled with median age and CD4+ counts of 33(IQR = 28–40) years and 428 (IQR = 145–689) cells/μL respectively. The prevalence of microalbuminuria was 18.9% (95% CI, 14–25%). None of the participants had macroalbuminuria. CD4+ count <350cells/μL was associated with increased risk of microalbuminuria (OR: 0.27, 95% CI: 0.12–0.59), P value = 0.001). Diabetes mellitus, hypertension, smoking, alcohol intake were not found to be significantly associated with microalbuminuria.

Conclusion

Microalbuminuria was highly prevalent in adult HIV − infected ART naive patients especially those with low CD4+ count. There is need to study the effect of ART on microalbuminuria in adult HIV − infected patients.

Association between the cytokine storm, immune cell dynamics, and viral replicative capacity in hyperacute HIV infection

INTRODUCTION

Immunological damage in acute HIV infection (AHI) may predispose to detrimental clinical sequela. However, studies on the earliest HIV-induced immunological changes are limited, particularly in sub-Saharan Africa. We assessed the plasma cytokines kinetics, and their associations with virological and immunological parameters, in a well-characterized AHI cohort where participants were diagnosed before peak viremia.

METHODS

Blood cytokine levels were measured using Luminex and ELISA assays pre-infection, during the hyperacute infection phase (before or at peak viremia, 1-11 days after the first detection of viremia), after peak viremia (24-32 days), and during the early chronic phase (77-263 days). Gag-protease-driven replicative capacities of the transmitted/founder viruses were determined using a green fluorescent reporter T cell assay. Complete blood counts were determined before and immediately following AHI detection before ART initiation.

RESULTS

Untreated AHI was associated with a cytokine storm of 12 out of the 33 cytokines analyzed. Initiation of ART during Fiebig stages I-II abrogated the cytokine storm. In untreated AHI, virus replicative capacity correlated positively with IP-10 (rho = 0.84, P < 0.001) and IFN-alpha (rho = 0.59, P = 0.045) and inversely with nadir CD4⁺ T cell counts (rho = - 0.58, P = 0.048). Hyperacute HIV infection before the initiation of ART was associated with a transient increase in monocytes (P < 0.001), decreased lymphocytes (P = 0.011) and eosinophils (P = 0.003) at Fiebig stages I-II, and decreased eosinophils (P < 0.001) and basophils (P = 0.007) at Fiebig stages III-V. Levels of CXCL13 during the untreated hyperacute phase correlated inversely with blood eosinophils (rho = - 0.89, P < 0.001), basophils (rho = - 0.87, P = 0.001) and lymphocytes (rho = - 0.81, P = 0.005), suggesting their trafficking into tissues. In early treated individuals, time to viral load suppression correlated positively with plasma CXCL13 at the early chronic phase (rho = 0.83, P = 0.042).

CONCLUSION

While commencement of ART during Fiebig stages I-II of AHI abrogated the HIV-induced cytokine storm, significant depletions of eosinophils, basophils, and lymphocytes, as well as transient expansions of monocytes, were still observed in these individuals in the hyperacute phase before the initiation of ART, suggesting that even ART initiated during the onset of viremia does not abrogate all HIV-induced immune changes.

HIV Infection Is Associated with Greater Left Ventricular Mass in the Multicenter AIDS Cohort Study

HIV infection has been associated with diastolic heart failure and atrial fibrillation. The purpose of this study is to determine whether HIV infection is associated with differences in left ventricular mass (LVM), left ventricular end-diastolic volume (LVEDV), and left atrial volume (LAV) indexed to body surface area (left ventricular mass index, left ventricular end-diastolic volume index [LVEDVI], and left atrial volume index [LAVI], respectively). Cross-sectional study of 721 men [425 HIV-infected (HIV+), 296 HIV-uninfected (HIV-) enrolled in the cardiovascular substudy of the Multicenter AIDS Cohort Study (MACS). Participants underwent cardiac computed tomography imaging. A blinded reader measured LVM, LVEDV, and LAV. We used multivariable linear regression models to evaluate whether LVEDVI, left ventricular mass index (LVMI), and LAVI differed by HIV serostatus, adjusting for demographics and cardiovascular disease risk factors. LVMI was significantly greater in HIV+ compared with HIV- men, with adjusted difference of 2.65 g/m2 (95% confidence interval 0.53-4.77, p < .001). Left ventricular end-diastolic index and LAVI did not differ significantly between the two groups. HIV-related factors (nadir CD4 count, clinical AIDS diagnosis, cumulative antiretroviral therapy use, and cumulative protease inhibitor use) were not significantly associated with LVMI, LVEDVI, or LAVI. LVM was significantly higher in HIV+ than HIV- men, which may contribute to the observed increased risk for diastolic heart failure associated with HIV infection. Although HIV infection has been associated with an increased risk for atrial fibrillation, we did not find any difference in LAV by HIV serostatus.

Prevalence of impaired renal function in virologically suppressed people living with HIV compared with controls: the Copenhagen Comorbidity in HIV Infection (COCOMO) study

OBJECTIVES

While renal impairment is reported more frequently in people living with HIV (PLWH) than in the general population, the PLWH samples in previous studies have generally been dominated by those at high renal risk.

METHODS

Caucasian PLWH who were virologically suppressed on antiretroviral treatment and did not have injecting drug use or hepatitis C were recruited from the Copenhagen Comorbidity in HIV Infection (COCOMO) study. Sex- and age-matched controls were recruited 1:4 from the Copenhagen General Population Study up to November 2016. We defined renal impairment as one measurement of estimated glomerular filtration rate ≤ 60 mL/min/1.73 m² , and assessed associated factors using adjusted logistic regression models. The impact of HIV-related factors was explored in a subanalysis.

RESULTS

Among 598 PLWH and 2598 controls, the prevalence of renal impairment was 3.7% [95% confidence interval (CI) 2.3-5.5%] and 1.7% (95% CI 1.2-2.2%; P = 0.0014), respectively. After adjustment, HIV status was independently associated with renal impairment [odds ratio (OR) 3.4; 95% CI 1.8-6.3]. In addition, older age [OR 5.4 (95% CI 3.9-7.5) per 10 years], female sex [OR 5.0 (95% CI 2.6-9.8)] and diabetes [OR 2.9 (95% CI 1.3-6.7)] were strongly associated with renal impairment. The association between HIV status and renal impairment became stronger with older age (P = 0.02 for interaction). Current and nadir CD4 counts, duration of HIV infection and previous AIDS-defining diagnosis were not associated with renal impairment among virologically suppressed PLWH.

CONCLUSIONS

The prevalence of renal impairment is low among low-risk virologically suppressed Caucasian PLWH, but remains significantly higher than in controls. Renal impairment therefore remains a concern in all PLWH and requires ongoing attention.

The baseline glomerular filtration rate, predictive of six-year survival in sub-Saharan African patients on antiretroviral therapy for HIV: Cohort study

BACKGROUND

Recently, serious morbidity events associated with initial glomerular filtration rate (GFR) have been described during HIV infection, but this is insufficiently investigated in sub-Saharan Africa very affected by HIV.

OBJECTIVE

To assess the impact of baseline GFR prevailing during the first semester of the HIV infection management on six-year survival in peoples taking antiretroviral therapy.

PATIENTS AND METHODS

Closed retrospective cohort study. The death was the expected outcome, the baseline GFR (mL/min/1.73m²) in the first semester of the follow-up was the main exposure. Kaplan-Meier method, Cox regression were used for analysis.

RESULTS

According to baseline GFR: <60, 60-89 and≥90, the six-year survival was 81.6%; 95.8% and 96.4% (P=0.067 Breslow). Adjusted hazard ratio for baseline GFR<60 and 60-89 (vs. ≥90) were respectively 5.4 (95%CI: 1.4-19.9; P=0.012) and 1.2 (95%CI: 0.3-4.0; P=0.754). The etiological fraction of deaths attributable to baseline GFR: GFR<60: 81% (95%CI: 0.31-0.95), GFR=60-89: 18.0% (95%CI: -0.7-0.8). Prognostic concordance index=0.84 (95%CI: 0.59-0.95) for GFR<60 and 0.55 (95%CI: 0.27-0.81) for GFR 60-89.

DISCUSSION

The etiological fraction of death and prognostic concordance index associated to baseline GFR level increase significantly with decline of baseline GFR.

CONCLUSION

Baseline GFR seems to predict the six-year survival in African sub-Saharan patients treated for HIV.

Chronic kidney disease and HIV in the era of antiretroviral treatment: findings from a 10-year cohort study in a west African setting

Background

It has been reported that people living with HIV in West Africa exhibited the highest risks for chronic kidney disease (CKD) in the world. Here, we aimed at determining the CKD frequency and changes in kidney function during antiretroviral treatment (ART) in a large cohort of HIV-patients followed in Burkina Faso.

Methods

We included ART-naive adults who initiated ART at the Day Care Unit of the Souro Sanou University Hospital between 01/01/2007 and 12/31/2016. We assessed the estimated glomerular filtration rate (eGFR) by serum creatinine using the Modification of Diet in Renal Disease (MDRD) equation. Following the K/DOQI recommendations, CKD was defined as eGFR < 60 ml/min/1.73m² at two consecutive measurements at least 3 months apart. The factors associated with eGFR decline or CKD were identified by mixed linear regression and Cox regression, respectively.

Results

Three thousand, one hundred and thirty-eight patients (72% women) were followed for a median (IQR) of 4.5(2.2–6.9) years. At baseline, median eGFR (IQR) was 110.7(94.4–128.4) ml/min/1.73m² and 93 (3%) patients exhibited eGFR < 60 ml/min/1.73m². The lowest-performing progressions of eGFR during the first year of ART were observed in patients with 40-49 yr. age range (− 8.3[− 11.7;-5.0] ml/min/1.73m², p < 0.001), age ≥ 50 yr. (− 6.2[− 10.7;-1.8] ml/min/1.73m², p = 0.006) and high blood pressure (HBP) (− 28.4[− 46.9;-9.9] ml/min/1.73m², p = 0.003) at ART initiation. Regarding the ART exposure in patients with normal baseline eGFR, zidovudine (AZT) with protease inhibitor (PI) (− 4.7[− 7.7;-1.6] ml/min/1.73m², p = 0.002), tenofovir (TDF) + PI (− 13.1[− 17.4;-8.7] ml/min/1.73m², p < 0.001), TDF without PI (− 3.2[− 5.0;-1.4] ml/min/1.73m², p < 0.001), stavudine (d4T) + PI (− 8.5[− 14.6–2.4] ml/min/1.73m², p = 0.006) and d4T without PI (− 5.0[− 7.6–2.4] ml/min/1.73m², p < 0.001) were associated with poorer eGFR progression. The prevalence of CKD was 0.5% and the incidence was 1.9 [1.3; 2.7] cases/1000 person-years. The risk of CKD was higher in patients with HBP (4.3[1.8;9.9], p = 0.001), 40-49 yr. patients (4.2[1.6;11.2], p = 0.004), ≥50 yr. patients (4.5[1.5;14.1], p = 0.009) and patients exposed to abacavir (ABC) or didanosine (ddI) based ART (13.1[4.0;42.9], p < 0.001).

Conclusions

Our findings do not confirm the high risk of CKD reported in previous studies of West Africans with HIV, but support the recommendations for early initiation of ART and close kidney function monitoring in patients with HBP or aged ≥40 yr.

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.

An overview of tenofovir and renal disease for the HIV-treating clinician

Tenofovir disoproxil fumarate (TDF, commonly termed ‘tenofovir’) is the antiretroviral most commonly implicated in antiretroviral-induced nephrotoxicity. As patients on successful antiretroviral therapy (ART) age, their risk for developing renal disease may increase in part because of ART itself, but more importantly, because of HIV-associated and non-HIV-associated comorbidity. Therefore, clinicians need an approach to managing renal disease in people on TDF. TDF as a cause of acute kidney injury (AKI) or chronic kidney disease (CKD) is uncommon, and clinicians should actively exclude other causes (Box 1). In TDF-associated AKI, TDF should be interrupted in all cases, and replaced, or ART interrupted altogether. Tenofovir disoproxil fumarate toxicity can present as AKI or CKD, and as a full or partial Fanconi’s syndrome. TDF has a small but definite negative impact on kidney function (up to a 10% decrease in glomerular filtration rate [GFR]). This occurs because of altered tubular function in those exposed to TDF for treatment and as pre-exposure prophylaxis. Renal function should be assessed using creatinine-based estimated GFR at the time of initiation of TDF, if ART is changed, at 1–3 months, and then ideally every 6–12 months if stable. Specific tests of tubular function are not routinely recommended; in the case of clinical concern, a spot protein or albumin: creatinine ratio is preferable, but in resource-limited settings, urine dipstick can be used. More frequent monitoring may be required in those with established CKD (estimated glomerular filtration rate [eGFR] < 50 mL/min/1.73 m²) or risk factors for kidney disease. The most common risk factors are comorbid hypertension, diabetes, HIV-associated kidney disease, hepatitis B or C co-infection, and TDF in combination with a ritonavir-boosted protease inhibitor. Management of these comorbid conditions must be prioritised in this group. If baseline screening eGFR is < 50 mL/min/1.73 m², abacavir (the preferred option), and dose-adjusted TDF (useful if concomitant hepatitis B), zidovudine or stavudine (d4T) remain alternatives to full-dose TDF. If there is a rapid decline in kidney function (eGFR drops by more than 25% and decreases to < 50 mL/min/1.73 m² from of baseline function), or there is new onset or worsening of proteinuria or albuminuria, clinicians should review ART and other potentially nephrotoxic medications and comorbidity and conduct further testing if indicated. If kidney function does not improve after addressing reversible causes of renal failure, then referral to a nephrologist is appropriate. In the case of severe CKD, timeous referral for planning for renal replacement therapy is recommended. Tenofovir alafenamide, a prodrug of tenofovir, appears to have less renal toxicity and is likely to replace TDF in future.

Chronic Kidney Disease in Persons Living with HIV: A Systematic Review

The purpose of our systematic review of research on chronic kidney disease (CKD) in persons living with HIV (PLWH) was to (a) compare and contrast diagnostic criteria for CKD, (b) identify risk factors of CKD in PLWH, and (c) elucidate the prevalence of CKD in PLWH. Keyword searches of PubMed and PsycInfo databases were followed by manual searches of references from 2000 through 2016; 21 studies met inclusion criteria. Sample sizes ranged from 8 to 15,140, with a mean age of 50 years, and represented diverse ethnicities/races and countries of origin. Fourteen studies were cross-sectional, six were cohort studies, and one was a case study. Major risk factors were related to hypertension, diabetes, and age. Prevalence ranged from 2.3% to 53.3% across a variety of countries and patient populations. The wide range in prevalence may have been due to differences in risk factors for the sample populations.

Early HIV infection among persons referred for malaria parasite testing in Nigeria

Persons in the early stages of HIV infection are the major drivers of new infections. These individuals may also develop renal dysfunctions at this time. Nigeria, as other African countries, has one of the highest prevalence of newly diagnosed HIV infections. Despite this, limited information exists on early HIV detection in the continent. This may be related to difficulties in providing early HIV diagnosis and treatment. Patients referred for malaria testing may provide a unique opportunity for early HIV detection. In this study, a method for identifying early HIV-infected individuals was assessed. HIV-1 subtype and renal function biomarkers were also analyzed in these persons. To identify early HIV infection, over a period of 18 months blood samples were collected from persons referred by clinicians for malaria parasite tests in Nigeria. A total of 671 samples were collected and analyzed for HIV antigen/antibody and subtypes. 101 of these samples were categorized into one of four groups: early HIV, chronic HIV, malaria infection and control groups for renal function analysis. 29% of HIV infected individuals were at the early stages of infection. The predominant subtype detected was CRF02_AG (57.14%). The early HIV group had the highest mean serum creatinine (95 µmol/L) and urea (5.7 mmol/L) values across all groups with the difference significant at P < 0.05. There was no significant difference between the circulating subtype and the stage of HIV infection. Our results show the feasibility of screening persons referred for malaria tests for early HIV. This can be used to control new HIV infections in sub-Saharan Africa.

Close Monitoring of eGFR Should Be Performed in HIV-Infected Patients Aged over 37 Years

Chronic kidney disease (CKD) has been shown to be a poor prognostic factor in HIV patients. This study aimed to identify risk factors in HIV-infected patients with early decline in renal function or an estimated glomerular filtration rate (eGFR) less than 90 mL/min/1.73 m². The study was retrospectively conducted at Panyananthaphikkhu Chonprathan Medical Center, Thailand. The inclusion criteria were HIV-infected adult patients who were treated at the hospital's HIV clinic and whose eGFR levels at the first visit had been evaluated. Eligible patients were categorized according to their eGFR level being lesser or greater than 90 mL/min/1.73 m². Multivariate logistic analysis was performed to evaluate the association of risk factors with an eGFR of less than 90 mL/min/1.73 m². There were 301 HIV-infected patients included in the study. Of those, 89 patients (29.57%) had an eGFR of less than 90 mL/min/1.73 m². Age was the only significant risk factor associated with an eGFR of less than 90 mL/min/1.73 m² with an adjusted odds ratio of 1.072 (95% confidence interval: 1.015-1.132). Age of over 37 years predicted an eGFR of less than 90 mL/min/1.73 m² as a risk factor in HIV-infected patients, with a sensitivity of 80.9% and specificity of 34.91%. Age was independently associated with eGFRs of less than 90 mL/min/1.73 m² in HIV-infected patients. Close monitoring of eGFR should be performed in HIV-infected patients aged over 37 years.

Analytic Considerations for Repeated Measures of eGFR in Cohort Studies of CKD

Repeated measures of various biomarkers provide opportunities for us to enhance understanding of many important clinical aspects of CKD, including patterns of disease progression, rates of kidney function decline under different risk factors, and the degree of heterogeneity in disease manifestations across patients. However, because of unique features, such as correlations across visits and time dependency, these data must be appropriately handled using longitudinal data analysis methods. We provide a general overview of the characteristics of data collected in cohort studies and compare appropriate statistical methods for the analysis of longitudinal exposures and outcomes. We use examples from the Chronic Renal Insufficiency Cohort Study to illustrate these methods. More specifically, we model longitudinal kidney outcomes over annual clinical visits and assess the association with both baseline and longitudinal risk factors.

Higher Cystatin C Levels Are Associated With Neurocognitive Impairment in Older HIV+ Adults

OBJECTIVE

The study aims to determine whether cystatin C is associated with HIV disease and HIV-associated neurocognitive impairment (NCI).

METHODS

Participants included 124 (HIV+ n = 77; HIV- n = 47) older adults (age ≥ 50 years) examined at the University of California, San Diego HIV Neurobehavioral Research Program. Cystatin C, a biomarker of kidney functioning that has been linked to poor health outcomes, was measured in blood. Participants completed a comprehensive neurocognitive assessment that was used to define both global and domain NCI.

RESULTS

The HIV+ group had significantly higher cystatin C concentrations than the HIV- group (d = 0.79 P < 0.001). Among HIV+ participants, those with NCI had higher cystatin C concentrations than those without NCI (d = 0.42, P = 0.055), particularly among participants taking tenofovir (d = 0.78, P = 0.004). A receiver-operator characteristic curve identified that cystatin C levels ≥0.75 mg/L were associated with NCI in the HIV+ group. Using this binary variable and including relevant covariates, multivariate modeling confirmed that NCI was associated with higher cystatin C levels (OR = 3.0; P = 0.03).

CONCLUSIONS

Our results confirm that HIV+ older adults have higher cystatin C than HIV- older adults and further identify that cystatin C may be associated with NCI in this population, particularly if they use tenofovir. This blood biomarker may be a useful clinical tool to identify older HIV+ persons at greater risk for cognitive decline.

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.

The Prevalence and Risk Factors of Renal Insufficiency among Korean HIV-Infected Patients: The Korea HIV/AIDS Cohort Study

BACKGROUND

Renal disease is one of the leading causes of morbidity and mortality among people infected with human immunodeficiency virus (HIV). However, there are very few published studies about renal insufficiency in HIV-infected persons in Asia, especially in South Korea.

MATERIALS AND METHODS

A cross-sectional study was performed to investigate the prevalence and risk factors of renal insufficiency, defined as <60 mL/min/1.73 m², in subjects in the Korea HIV/AIDS Cohort Study enrolled from 19 institutions between December 2006 and July 2013. Data at entry into the cohort were analyzed.

RESULTS

Of 454 enrolled subjects, 24 (5.3%) showed renal insufficiency at entry into the cohort. The mean age of patients in the renal insufficiency group was 5.28 years and the majority were male subjects (91.7%). All the patients were receiving antiretroviral agents, mostly protease inhibitor-based regimens (76.4%), for an average of 19 months. In univariate analysis, older age (P = 0.002), diabetes mellitus (DM) (P = 0.0002), unknown route of transmission (P = 0.007), and taking indinavir (P = 0.0022) were associated with renal insufficiency. In multivariable analysis, older age [odds ratio (OR) 1.07, 95% confidence interval (CI) 1.03-1.12, P = 0.002], DM [OR 3.03, 95% CI 1.17-7.82, P = 0.022], unknown route of transmission [OR 6.15, 95% CI 1.77-21.33, P = 0.004], and taking indinavir [OR 3.07, 95% CI 1.17-8.05, P = 0.023] were independent risk factors of renal insufficiency.

CONCLUSION

The prevalence of renal insufficiency in HIV-infected subjects in this study was relatively low, similar to that in other countries. Aging, DM, and taking indinavir were significantly associated with decreased glomerular filtration rate. Furthermore, unknown route of transmission was an independent risk factor, which was interpreted as a reflection of patient compliance. Further studies on the incidence and risk factors of renal insufficiency during HIV infection using follow-up cohort data are necessary.

Association of Kidney Function and Early Kidney Injury With Incident Hypertension in HIV-Infected Women

Subclinical kidney disease is associated with developing hypertension in the general population, but data are lacking among HIV-infected people. We examined associations of kidney function and injury with incident hypertension in 823 HIV-infected and 267 HIV-uninfected women in the Women's Interagency HIV Study, a multicenter, prospective cohort of HIV-infected and uninfected women in the United States. Baseline kidney biomarkers included estimated glomerular filtration rate using cystatin C, urine albumin-to-creatinine ratio, and 7 urine biomarkers of tubular injury: α-1-microglobulin, interleukin-18, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, liver fatty acid-binding protein, N-acetyl-β-d-glucosaminidase, and α1-acid-glycoprotein. We used multivariable Poisson regression to evaluate associations of kidney biomarkers with incident hypertension, defined as 2 consecutive visits of antihypertensive medication use. During a median follow-up of 9.6 years, 288 HIV-infected women (35%) developed hypertension. Among the HIV-infected women, higher urine albumin-to-creatinine ratio was independently associated with incident hypertension (relative risk =1.13 per urine albumin-to-creatinine ratio doubling, 95% confidence interval, 1.07-1.20), as was lower estimated glomerular filtration rate (relative risk =1.10 per 10 mL/min/1.73 m² lower estimated glomerular filtration rate; 95% confidence interval, 1.04-1.17). No tubular injury and dysfunction biomarkers were independently associated with incident hypertension in HIV-infected women. In contrast, among the HIV-uninfected women, urine albumin-to-creatinine ratio was not associated with incident hypertension, whereas higher urine interleukin-18, α1-acid-glycoprotein, and N-acetyl-β-d-glucosaminidase levels were significantly associated with incident hypertension. These findings suggest that early glomerular injury and kidney dysfunction may be involved in the pathogenesis of hypertension in HIV-infected people. The associations of tubular markers with hypertension in HIV-uninfected women should be validated in other studies.

Prevalence and predictors of chronic kidney disease in newly diagnosed human immunodeficiency virus patients in Owerri, Nigeria

Human immunodeficiency virus (HIV) infection is a common cause of chronic kidney disease (CKD) in Sub-Saharan Africa. This study aims at identifying the prevalence and predictors of CKD in newly diagnosed HIV patients in Owerri, South East Nigeria. This was a cross-sectional study consisting of 393 newly diagnosed HIV-seropositive subjects and 136 age- and sex-matched seronegative subjects as controls. CKD was defined as 24-hour urine protein (24-HUP) ≥0.3 g and/or glomerular filtration rate (GFR) < 60 ml/min. Subjects were recruited from the HIV clinic and the Medical Outpatient Department of Federal Medical Centre, Owerri. Clinical and anthropometric data were collected. Relevant investigations were performed, including HIV screening and relevant urine and blood investigations. The mean age of the HIV subjects was 38.84 ± 10.65 years. CKD was present in 86 (22.9%) HIV subjects and 11 (8.l %) controls. Low waist circumference (WC), high serum creatinine, high spot urine protein/creatinine ratio (SUPCR), high 24-HUP/creatinine Ratio (24-HUPCR), high 24-HUP/osmolality Ratio (24-HUPOR) predicted CKD in HIV subjects. CKD prevalence is high (22.9%) among newly diagnosed HIV patients in South East Nigeria. The predictors of CKD included WC, serum creatinine, SUPCR, 24-HUPCR, and 24-HUPOR.

Proximal tubular dysfunction and kidney injury associated with tenofovir in HIV patients: a case series

Background

Tenofovir disoproxil fumarate (TDF) may cause acute kidney injury and proximal tubular dysfunction. However, no detailed studies document urinary phosphate wasting as a marker of TDF-induced tubulopathy.

Methods

Records of HIV-infected patients with presumed TDF toxicity were reviewed. We describe the characteristics and clinical course of 15 patients who had documented elevated (>20%) fractional excretion of phosphate (FEphos).

Results

Patients were predominantly Caucasian and male (73 and 80%, respectively), with a mean age of 56 years (range 38–76). Of the 15 patients, 11 had a estimated glomerular filtration rate (eGFR) of >90 mL/min/1.73² at time of TDF initiation. The mean duration of TDF therapy prior to diagnosis of TDF toxicity was 64 months. Mean FEphos was 34% (range 20–62). The mean eGFR at TDF initiation was 104 mL/min/1.73 m² [standard deviation (SD) 17.0] with a gradual decline to 69 mL/min/1.73 m² (SD 19.0) by the time of TDF discontinuation. Of 10 patients with repeated FEphos after TDF discontinuation, 9 had improvement of their FEphos. Of these individuals, 6 had normalization of their FEphos. Estimated GFR improved in 12 patients after discontinuation of TDF, though importantly, none returned to their baseline eGFR.

Conclusions

Urinary phosphate wasting is a sensitive marker for TDF-induced proximal tubulopathy and is associated with unrecognized and permanent renal function decline. Tubular dysfunction can develop after years of TDF therapy in those with normal kidney function at the time of drug initiation. This suggests that continuing vigilance be maintained in all those on TDF.

Monitoring of kidney function in HIV-positive patients

HIV-positive patients are at increased risk of developing chronic kidney disease. Although guidelines recommend regular monitoring of renal function in individuals living with HIV, the optimal frequency remains to be defined. In this review, we discuss the renal syndromes that may be identified at an earlier stage via routine assessment of kidney function, and provide guidance in terms of the frequency of monitoring, the most useful tests to perform, and their clinical significance. Specifically, we address whether annual monitoring of kidney function is appropriate for the majority of HIV-positive patients.

Evaluation of the Prognostic Value of Impaired Renal Function on Clinical Progression in a Large Cohort of HIV-Infected People Seen for Care in Italy

Whilst renal dysfunction, especially mild impairment (60<eGFR<90 ml/min), has been often described in HIV-infected population, its potential contribution to HIV evolution and risk of cerebro-cardiovascular disease (CCVD) has not been clarified. Data from HIV-1 infected patients enrolled in the Italian Cohort of Antiretroviral-Naïve (Icona) Foundation Study collected between January 2000 and February 2014 with at least two creatinine values available. eGFR (CKD-epi) and renal dysfunction defined using a priori cut-offs of 60 (severely impaired) and 90 ml/min/1.73m² (mildly impaired). Characteristics of patients were described after stratification in these groups and compared using chi-square test (categorical variables) or Kruskal Wallis test comparing median values. Follow-up accrued from baseline up to the date of the CCVD or AIDS related events or death or last available visit. Kaplan Meier curves were used to estimate the cumulative probability of occurrence of the events over time. Adjusted analysis was performed using a proportional hazards Cox regression model. We included 7,385 patients, observed for a median follow-up of 43 months (inter-quartile range [IQR]: 21-93 months). Over this time, 130 cerebro-cardiovascular events (including 11 deaths due to CCVD) and 311 AIDS-related events (including 45 deaths) were observed. The rate of CCVD events among patients with eGFR >90, 60-89, <60 ml/min, was 2.91 (95% CI 2.30-3.67), 4.63 (95% CI 3.51-6.11) and 11.9 (95% CI 6.19-22.85) per 1,000 PYFU respectively, with an unadjusted hazard ratio (HR) of 4.14 (95%CI 2.07-8.29) for patients with eGFR <60 ml/min and 1.58 (95%CI 1.10-2.27) for eGFR 60-89 compared to those with eGFR ≥90. Of note, these estimates are adjusted for traditional cardio-vascular risk factors (e.g. smoking, diabetes, hypertension, dyslipidemia). Incidence of AIDS-related events was 9.51 (95%CI 8.35-10.83), 6.04 (95%CI 4.74-7.71) and 25.0 (95%CI 15.96-39.22) per 1,000 PYFU, among patients with eGFR >90, 60-89, <60 ml/min, respectively, with an unadjusted HR of 2.49 (95%CI 1.56-3.97) for patients with eGFR <60 ml/min and 0.68 (95%CI 0.52-0.90) for eGFR 60-89. The risk of AIDS events was significantly lower in mild renal dysfunction group even after adjustment for HIV-related characteristics. Our data confirm that impaired renal function is an important risk marker for CCVD events in the HIV-population; importantly, even those with mild renal impairment (90<eGFR<60) seem to be at increased risk of cerebro-cardiovascular morbidity and mortality.

Proximal renal tubular dysfunction related to antiretroviral therapy among HIV-infected patients in an HIV clinic in Mexico

Proximal renal tubular dysfunction (PRTD) of varying severity has been associated with antiretroviral toxicity, especially related to the use of tenofovir (TDF). The aim of this study was to investigate whether HIV-infected patients who use a tenofovir-based regimen are at increased risk of tubular dysfunction. We conducted an observational, comparative, longitudinal, prospective study. Estimated glomerular filtration rate (eGFR) and markers of tubular damage to assess tubular dysfunction (fractional excretion of phosphate and uric acid, glycosuria, and proteinuria) were measured at baseline and at weeks 12 and 24. Of 111 participants, PRTD was found in 6.3% at week 12 and 9% at week 24, with no statistically significant difference between those on an abacavir (ABC)-containing regimen or a TDF-containing regimen. We also found an increase in triglycerides associated with the ABC-containing regimen compared with the TDF group. The use of an ABC- or TDF-containing regimen was independently associated with tubular dysfunction, but we found no significant differences between these groups, except when TDF was combined with a protease inhibitor. A better and more complete assessment of renal function is needed, because the presence of tubular dysfunction and proteinuria without impairment of eGFR may affect the renal safety of HIV-infected patients.

Relationships between renal parameters and serum and urine markers of inflammation in those with and without HIV infection

We sought to determine the relationships among intrarenal and systemic inflammation and renal disease in HIV. We compared paired serum and urinary levels (normalized to urine creatinine) of monocyte chemotactic protein-1 (MCP-1), regulated on activation normal T cell expressed and secreted (RANTES), interferon-γ-induced protein-10 (IP-10), interleukin-8 (IL-8), and β2-microglobulin (B2M) between two groups of HIV-infected subjects not receiving antiretroviral therapy (ART) [A: not expecting to initiate ART immediately due to having CD4 cell counts ≥350/μl, N=26; B: about to initiate ART, N=19], a group of HIV-infected subjects receiving virologically suppressive antiretroviral therapy [C, N=30], and a group of HIV-uninfected, healthy volunteers [D, N=45]. We then correlated these inflammatory biomarker levels with urine protein/creatinine ratios (uPCR), urine albumin/creatinine ratios (uACR), and estimated glomerular filtration rates (eGFR). Urine inflammatory biomarker levels were highest in Group B. When combining all four study groups, statistically significant positive correlations included uPCR with urine IL-8, urine MCP-1, urine IP-10, and serum IP-10 and uACR with urine IL-8, urine B2M, serum IP-10, and serum B2M. eGFR was statistically significantly negatively correlated with serum MCP-1 and serum B2M. Paired serum and urine levels of IP-10 and B2M (but not IL-8, RANTES, or MCP-1) were significantly correlated with each other in the overall group. The levels of urine inflammatory markers tested differed by HIV status and use of virologically suppressive ART. These urine and serum inflammatory markers were differentially correlated with uPCR, uACR, and eGFR, suggesting that different intrarenal and systemic inflammatory pathways may contribute to different measures of nephropathy.

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.

Race and other risk factors for incident proteinuria in a national cohort of HIV-infected veterans

BACKGROUND

Proteinuria in human immunodeficiency virus (HIV)-infected individuals has been associated with poorer outcomes. We examined risk factors associated with the development of proteinuria in a national registry of HIV-infected veterans.

METHODS

A total of 21,129 HIV-infected veterans of black and white race without preexisting kidney disease were receiving health care in the Veterans' Health Administration (VHA) medical system between 1997 and 2011. Using the VHA electronic record system, we identified kidney-related risk factors (hypertension, diabetes, and cardiovascular disease) and HIV-related risk factors (CD4 lymphocyte count, HIV RNA level, hepatitis C virus, and hepatitis B virus) for developing proteinuria. Proteinuria was defined by 2 consecutive dipstick measures of 1 or higher. The Fine-Gray competing risk model was used to estimate association between clinical variables and incident proteinuria, while accounting for intervening mortality events.

RESULTS

During follow-up (median = 5.3 years), 7031 patients developed proteinuria. Overall, black race compared with white race was associated with a higher risk of proteinuria {hazard ratio [95% confidence interval (CI)] = 1.51 [1.43 to 1.59]}, but the association was stronger at younger ages (P interaction <0.001). Age-stratified risk of proteinuria for blacks relative to whites was greatest among veterans <30 years [2.19 (1.66 to 2.89)] and the risk diminished with increasing age [1.14 (0.97 to 1.34) for >60 years]. We found the race difference to be stronger for the outcome of 2 or higher proteinuria [2.13 (1.89 to 2.39)]. Both HIV-related and traditional risk factors were also associated with incident proteinuria (P < 0.05).

CONCLUSIONS

Compared with whites, risk of proteinuria was higher in black veterans with HIV infection, particularly at younger ages. In both races, HIV- and kidney-related risk factors were associated with higher proteinuria risk.

Association of urine α1-microglobulin with kidney function decline and mortality in HIV-infected women

BACKGROUND AND OBJECTIVES

Despite advances in therapy, HIV-infected individuals remain at higher risk for kidney dysfunction than uninfected individuals. It was hypothesized that urine levels of α1-microglobulin, a biomarker of proximal tubular dysfunction, would predict kidney function decline and mortality risk in HIV-infected and uninfected women.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In the Women's Interagency HIV Study, urine α1-microglobulin and creatinine concentrations were measured in 903 HIV-infected and 287 uninfected women using stored urine from 1999 to 2000, when prevalence of tenofovir use was <1%. Participants were categorized into three categories by level of α1-microglobulin-to-creatinine ratio, and associations with kidney decline and all-cause mortality over 8 years were evaluated.

RESULTS

Urine α1-microglobulin was detectable in 60% of HIV-infected and 40% of uninfected women (P<0.001). Among HIV-infected women, there were 177 (22%), 61 (7%), and 128 (14%) patients with incident CKD, with 10% annual eGFR decline, and who died, respectively. Compared with HIV-infected women in the lowest α1-microglobulin category, HIV-infected women in the highest α1-microglobulin category had a 2.1-fold risk of incident CKD (95% confidence interval, 1.3 to 3.4), 2.7-fold risk of 10% annual eGFR decline (95% confidence interval, 1.2 to 5.9), and 1.6-fold mortality risk (95% confidence interval, 1.0 to 2.6) in models adjusting for kidney risk factors, baseline eGFR, and albuminuria. Among uninfected women, the highest α1-microglobulin category was associated with 3% (relative risk, 2.2; 95% confidence interval, 1.4 to 3.5) and 5% (relative risk, 2.2; 95% confidence interval, 1.1 to 4.3) annual eGFR decline relative to the lowest α1-microglobulin category.

CONCLUSIONS

Proximal tubular dysfunction, indicated by urine α1-microglobulin, was independently associated with kidney function decline in HIV-infected and uninfected women and mortality risk among HIV-infected women.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Screening for decreased glomerular filtration rate and associated risk factors in a cohort of HIV-infected patients in a middle-income country

With the introduction of combined active antiretroviral therapy and the improved survival of HIV-infected patients, degenerative diseases and drug toxicity have emerged as long-term concerns. We studied the prevalence of decreased glomerular filtration rate (GFR) and associated risk factors in a cohort of HIV-infected patients from a middle-income country. Our cross-sectional study included all adult patients who attended an urban outpatient clinic in 2008. GFR was estimated using the CKD-EPI equation. The prevalence ratio (PR) of decreased GFR (defined as <60 mL/min/1.73 m²) was estimated using generalizing linear models assuming a Poisson distribution. We analyzed data from 1,970 patients, of which 82.9% had been exposed to ART. A total of 249 patients (12.6%) had a GFR between 60 and 89 mL/min/1.73 m², 3.1% had a GFR between 30 and 59, 0.3% had a GFR between 15 and 29, and 0.4% had a GFR <15. Decreased GFR was found in only 74 patients (3.8%). In the multivariate regression model, the factors that were independently associated with a GFR below 60 mL/min/1.73 m² were as follows: age ≥50 years (PR = 3.4; 95% CI: 1.7–6.8), diabetes (PR = 2.0; 95% CI: 1.2–3.4), hypertension (PR = 2.0; 95% CI: 1.3–3.2), current CD4+ cell count <350 cells/mm3 (PR = 2.1; 95% CI: 1.3–3.3), past exposure to tenofovir (PR = 4.7; 95% CI: 2.3–9.4) and past exposure to indinavir (PR = 1.7; 95% CI: 1.0–2.8). As in high-income countries, CKD was the predominant form of kidney involvement among HIV-infected individuals in our setting. The risk factors associated with decreased glomerular filtration were broad and included virus-related factors as well as degenerative and nephrotoxic factors. Despite the potential for nephrotoxicity associated with some antiretroviral drugs, in the short-term, advanced chronic renal disease remains very rare.

Impaired Urine Dilution Capability in HIV Stable Patients

Renal disease is a well-recognized complication among patients with HIV infection. Viral infection itself and the use of some antiretroviral drugs contribute to this condition. The thick ascending limb of Henle's loop (TALH) is the tubule segment where free water clearance is generated, determining along with glomerular filtration rate the kidney's ability to dilute urine. Objective. We analyzed the function of the proximal tubule and TALH in patients with HIV infection receiving or not tenofovir-containing antiretroviral treatment in comparison with healthy seronegative controls, by applying a tubular physiological test, hyposaline infusion test (Chaimowitz' test). Material & Methods. Chaimowitz' test was performed on 20 HIV positive volunteers who had normal renal functional parameters. The control group included 10 healthy volunteers. Results. After the test, both HIV groups had a significant reduction of serum sodium and osmolarity compared with the control group. Free water clearance was lower and urine osmolarity was higher in both HIV+ groups. Proximal tubular function was normal in both studied groups. Conclusion. The present study documented that proximal tubule sodium reabsorption was preserved while free water clearance and maximal urine dilution capability were reduced in stable HIV patients treated or not with tenofovir.

Deteriorating renal function and clinical outcomes in HIV-positive persons

OBJECTIVES

To determine the relationship between measures of renal function [current estimated glomerular filtration rate (eGFR) and proportion of follow-up with a low eGFR (%FU ≤60 ml/min)] and fatal/ nonfatal AIDS, non-AIDS events and all-cause mortality.

DESIGN

An observational, longitudinal cohort study of 12 155 persons from EuroSIDA.

METHODS

Persons with at least one eGFR measurement after 1 January 2004, using the CKD-EPI formula, were included. Poisson regression analyses were used to determine whether current eGFR or %FU of 60 ml/min or less were independent prognostic markers for clinical events.

RESULTS

During 61 425 person-years of follow-up (PYFU), the crude incidence of deaths was 11.1/1000 PYFU [95% confidence interval (CI) 10.0-12.1] at current eGFR more than 90 ml/min and 199.6 (95% CI 1144.3-254.3/1000 PYFU) when current eGFR was 30 ml/min or less. Corresponding figures for AIDS were 12.2 (11.1-13.3) and 63.9 (36.5-103.7) and for non-AIDS were 16.0 (14.8-17.3) and 203.6 (147.7-259.5). After adjustment, current eGFR of 30 ml/min or less was a strong predictor of death [adjusted incidence rate ratios (aIRR) 4.35; 95% CI 3.20-5.91] and non-AIDS events (3.63; 95% CI 2.57-5.13), although the relationship with AIDS was less strong (1.45; 95% CI 1.01-2.08). After adjustment, %FU of 60 ml/min or less was associated with a 22% increased incidence of death (aIRR 1.22 per 10% longer; 95% CI 1.18-1.27), a 13% increased incidence of non-AIDS events (95% CI 1.08-1.18) and a 15% increased incidence of AIDS events (95% CI 1.06-1.24).

CONCLUSION

Both current eGFR and %FU of 60 ml/min or less were associated with death and non-AIDS events in HIV-positive persons. Our findings highlight the association between underlying renal dysfunction and morbidity and mortality in HIV infection, although reverse causality cannot be excluded.

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 of and associated factors with chronic kidney disease in human immunodeficiency virus-infected patients in Taiwan

BACKGROUND

Chronic kidney disease (CKD) is an important issue for individuals who live with human immunodeficiency virus (HIV) following the use of highly active antiretroviral therapy; however, the prevalence rate of CKD varies between countries.

METHODS

The present study screened HIV-infected patients in a medical center and a regional teaching hospital in southern Taiwan from January 2008 to December 2012. CKD was defined as a urine microalbumin-to-creatinine ratio ≥30 mg/g, and/or a protein ≥1 + on urine dipstick examination, and/or an estimated glomerular filtration rate <60 mL/min/1.73 m(2) for 3 months. The prevalence rate and the analyzed associated factors of CKD were determined.

RESULTS

Among 1639 HIV-infected patients, only 512 had adequate data to be enrolled in the study. Thirty-six (7.03%) of these patients had CKD, and 476 did not. In a univariate analysis, CKD was associated with an older age, a higher peak HIV RNA load, diabetes mellitus (DM), hypertension, exposure to antiretroviral therapy, and cholesterol levels ≥240 mg/dL. Multivariate analysis revealed that DM, hypertension, and cholesterol ≥240 mg/dL were statistically significant factors.

CONCLUSION

In Taiwan, the prevalence of CKD in HIV-infected patients was low (7.03%). The classical risk factors for CKD, such as DM, hypertension, and hypercholesterolemia, were demonstrated to be associated with CKD in Taiwanese HIV-infected patients.

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.

Comparisons of creatinine and cystatin C for detection of kidney disease and prediction of all-cause mortality in HIV-infected women

BACKGROUND

Cystatin C could improve chronic kidney disease (CKD) classification in HIV-infected women relative to serum creatinine.

DESIGN

Retrospective cohort analysis.

METHODS

Cystatin C and creatinine were measured from specimens taken and stored during the 1999-2000 examination among 908 HIV-infected participants in the Women's Interagency HIV study (WIHS). Mean follow-up was 10.2 years. Predictors of differential glomerular filtration rate (GFR) estimates were evaluated with multivariable linear regression. The associations of baseline categories (<60, 60-90, and >90 ml/min per 1.73 m) of creatinine estimated GFR (eGFRcr), cystatin C eGFR (eGFRcys), and combined creatinine-cystatin C eGFR (eGFRcr-cys) with all-cause mortality were evaluated using multivariable Cox regression. The net reclassification index (NRI) was calculated to evaluate the effect of cystatin C on reclassification of CKD staging.

RESULTS

CKD risk factors were associated with lower eGFRcys and eGFRcr-cys values compared with eGFRcr. Relative to eGFR more than 90, the eGFR less than 60 category by eGFRcys (Adjusted hazard ratio: 2.56; 95% confidence interval: 1.63-4.02), eGFRcr-cys (3.11; 1.94-5.00), and eGFRcr (2.34; 1.44-3.79) was associated with increased mortality risk. However, the eGFR 60-90 category was associated with increased mortality risk for eGFRcys (1.80; 1.28-2.53) and eGFRcr-cys (1.91; 1.38-2.66) but not eGFRcr (1.20; 0.85-1.67). The overall NRI for mortality was 26% when reclassifying from eGFRcr to eGFRcys (P < 0.001) and was 20% when reclassifying from eGFRcr to eGFRcr-cys (P < 0.001).

CONCLUSION

The addition of cystatin C may improve mortality risk prediction by stages of kidney function relative to creatinine. CKD risk factors are associated with an overestimate of GFR by serum creatinine relative to cystatin C.

Does HIV infection promote early kidney injury in women?

BACKGROUND

In HIV-infected women, urine concentrations of novel tubulointerstitial injury markers, interleukin-18 (IL-18) and kidney injury marker-1 (KIM-1), are associated with kidney function decline and all-cause mortality. We hypothesized that HIV-infected individuals with preserved kidney filtration function would have more extensive kidney injury, as determined by urine injury markers, compared to the uninfected controls, and that risk factors for tubulointerstitial injury would differ from risk factors for albuminuria.

METHODS

In this cross-sectional study, we compared urine concentrations of IL-18, KIM-1 and albumin-to-creatinine ratio (ACR) in 908 HIV-infected and 289 HIV-uninfected women enrolled in the Women's Interagency HIV Study, utilizing stored urine specimens from visits between 1999 and 2000.

RESULTS

After multivariate-adjusted linear regression analysis, mean urine concentrations were higher in HIV-infected individuals by 38% for IL-18 (P<0.0001), 12% for KIM-1 (P=0.081) and 47% for ACR (P<0.0001). Higher HIV RNA level (15% per 10-fold increase; P<0.0001), lower CD4(+) lymphocyte count (8% per doubling; P=0.0025), HCV infection (30%; P=0.00018) and lower high-density lipoprotein (5% per 10 mg/dl; P=0.0024) were each associated with higher IL-18 concentrations. In contrast, hypertension (81%; P<0.0001) and diabetes (47%; P=0.018) were among the strongest predictors of higher ACR, though HIV RNA level (15% per 10-fold increase; P=0.0004) was also associated with higher ACR.

CONCLUSIONS

HIV-infected women had more extensive tubulointerstitial and glomerular injury than uninfected women, but the associated factors differed among the urine biomarkers. Combinations of urinary biomarkers should be investigated to further characterize early kidney injury in HIV-infected women.

How to manage HIV-infected patients with chronic kidney disease in the HAART era

As human immunodeficiency virus (HIV)-infected patients now live longer while receiving highly active antiretroviral therapy (HAART), chronic kidney disease (CKD) has emerged as a significant cause of morbidity and mortality among urban HIV population. Risk factors associated with CKD in such HIV-infected population include aging, hypertension, diabetes mellitus, co-infection with hepatitis C virus, low CD4 cell count, and high HIV viral load. Clinical experience has shown that HIV-infected individuals often have one or more concurrent risk factors for CKD. The cumulative effect of multiple risk factors on the development of CKD should be noted in this population. Glomerular disease directly related to HIV infection, so-called HIV-associated nephropathy, remains an important cause of CKD among limited HIV population of African descent. The impact of exposure to nephrotoxic antiretroviral agents on the development of kidney disease is both an old and a new concern. In particular, the association of tenofovir with kidney disease has been an area of great interest. The findings regarding tenofovir's adverse effect on long-term kidney function vary among studies. Early identification and treatment of kidney disease is imperative for reducing the burden of patients requiring dialysis in HIV-infected populations. Periodic monitoring of urinary albumin excretion, tubular parameters such as low-molecular-weight proteinuria, and the estimated glomerular filtration rate may be useful for early diagnosis of patients at risk for incident CKD. This review focuses on recent developments in epidemiology, risk factors, identification, estimation, and management of CKD in HIV-infected population in the HAART era.

Baseline kidney function as predictor of mortality and kidney disease progression in HIV-positive patients

BACKGROUND

Chronic kidney disease (CKD) is associated with increased all-cause mortality and kidney disease progression. Decreased kidney function at baseline may identify human immunodeficiency virus (HIV)-positive patients at increased risk of death and kidney disease progression.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

7 large HIV cohorts in the United Kingdom with kidney function data available for 20,132 patients.

PREDICTOR

Baseline estimated glomerular filtration rate (eGFR).

OUTCOMES

Death and progression to stages 4-5 CKD (eGFR <30 mL/min/1.73 m(2) for >3 months) in Cox proportional hazards and competing-risk regression models.

RESULTS

Median age at baseline was 34 (25th-75th percentile, 30-40) years, median CD4 cell count was 350 (25th-75th percentile, 208-520) cells/μL, and median eGFR was 100 (25th-75th percentile, 87-112) mL/min/1.73 m(2). Patients were followed up for a median of 5.3 (25th-75th percentile, 2.0-8.9) years, during which 1,820 died and 56 progressed to stages 4-5 CKD. A U-shaped relationship between baseline eGFR and mortality was observed. After adjustment for potential confounders, eGFRs <45 and >105 mL/min/1.73 m(2) remained associated significantly with increased risk of death. Baseline eGFR <90 mL/min/1.73 m(2) was associated with increased risk of kidney disease progression, with the highest incidence rates of stages 4-5 CKD (>3 events/100 person-years) observed in black patients with eGFR of 30-59 mL/min/1.73 m(2) and those of white/other ethnicity with eGFR of 30-44 mL/min/1.73 m(2).

LIMITATIONS

The relatively small numbers of patients with decreased eGFR at baseline and low rates of progression to stages 4-5 CKD and lack of data for diabetes, hypertension, and proteinuria.

CONCLUSIONS

Although stages 4-5 CKD were uncommon in this cohort, baseline eGFR allowed the identification of patients at increased risk of death and at greatest risk of kidney disease progression.

Total protein, albumin and low-molecular-weight protein excretion in HIV-positive patients

BACKGROUND

Chronic kidney disease is common in HIV positive patients and renal tubular dysfunction has been reported in those receiving combination antiretroviral therapy (cART). Tenofovir (TFV) in particular has been linked to severe renal tubular disease as well as proximal tubular dysfunction. Markedly elevated urinary concentrations of retinal-binding protein (RBP) have been reported in patients with severe renal tubular disease, and low-molecular-weight proteins (LMWP) such as RBP may be useful in clinical practice to assess renal tubular function in patients receiving TFV. We analysed 3 LMWP as well as protein and albumin in the urine of a sample of HIV positive patients.

METHODS

In a cross-sectional fashion, total protein, albumin, RBP, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) were quantified in random urine samples of 317 HIV positive outpatients and expressed as the ratio-to-creatinine (RBPCR, CCR and NGALCR). Exposure to cART was categorised as none, cART without TFV, and cART containing TFV and a non-nucleoside reverse-transcriptase-inhibitor (TFV/NNRTI) or TFV and a protease-inhibitor (TFV/PI).

RESULTS

Proteinuria was present in 10.4 % and microalbuminuria in 16.7 % of patients. Albumin accounted for approximately 10 % of total urinary protein. RBPCR was within the reference range in 95 % of patients while NGALCR was elevated in 67 % of patients. No overall differences in urine protein, albumin, and LMWP levels were observed among patients stratified by cART exposure, although a greater proportion of patients exposed to TFV/PI had RBPCR >38.8 μg/mmol (343 μg/g) (p = 0.003). In multivariate analyses, black ethnicity (OR 0.43, 95 % CI 0.24, 0.77) and eGFR <75 mL/min/1.73 m2 (OR 3.54, 95 % CI 1.61, 7.80) were independently associated with upper quartile (UQ) RBPCR. RBPCR correlated well to CCR (r2 = 0.71), but not to NGALCR, PCR or ACR.

CONCLUSIONS

In HIV positive patients, proteinuria was predominantly of tubular origin and microalbuminuria was common. RBPCR in patients without overt renal tubular disease was generally within the reference range, including those receiving TFV. RBP therefore appears a promising biomarker for monitoring renal tubular function in patients receiving TFV and for distinguishing patients with normal tubular function or mild tubular dysfunction from those with severe renal tubular disease or Fanconi syndrome.