Tubular and glomerular proteinuria in HIV-infected adults with estimated glomerular filtration rate ≥ 60 ml/min per 1.73 m2

Hepatitis C virus infection is associated with proteinuria according to a systematic review with meta-analysis

INTRODUCTION AND AIM

Hepatitis C virus infection and chronic kidney disease are major public health issues all over the world. It has been suggested a role of HCV as a risk factor for the development and progression of chronic kidney disease (defined by reduced glomerular filtration rate and/or detectable proteinuria) in the general population but conflicting findings have been given.

MATERIAL AND METHODS

A systematic review of the published medical literature was conducted to assess whether positive HCV serologic status is associated with greater rate of proteinuria in the adult general population. We used a random-effect model to generate a summary estimate of the relative risk of proteinuria with HCV across the published studies.

RESULTS

We identified 23 studies (n=198,967 unique patients) and performed separate meta-analyses according to the study design. Overall effect estimate was significant in cross-sectional (OR, 1.47, 95%CI, 1.3; 1.66) (P<0.001) and obvious between-study heterogeneity was observed (Q value by Chi-squared [χ2] test 27.3, P=0.02). The risk of proteinuria after exposure to HCV was also consistent among longitudinal studies (HR, 1.79, 95% CI, 1.17; 2.74) (P<0.001) and between-study heterogeneity occurred (Q value, 27.82 by X2 test, P=0.0001). Stratified analysis did not report heterogeneity in several comparisons-pooling studies based on urine protein/creatinine ratio (UACR) showed that the adjusted OR with HCV was 1.64 (95% CI, 1.41; 1.91, P<0.001) without heterogeneity (Q value by Chi-squared [χ2] test 9.98, P=NS). Meta-regression recorded a link between greater prevalence of proteinuria in males with HCV exposure (P=0.03). Studies based on univariate analysis (n=6, n=72, 551 unique patients) gave similar results, pooled OR 1.54 (95% CI, 1.08; 2.19) (P=0.0001).

CONCLUSIONS

An important relationship between HCV infection and higher risk of proteinuria in the general population exists. Research aimed to understand the biological mechanisms underlying such association is under way. We encourage to screen all patients with HCV exposure for proteinuria.

Acute kidney injury in critical COVID-19 patients: usefulness of urinary biomarkers and kidney proximal tubulopathy

Tubular injury is the main cause of acute kidney injury (AKI) in critically ill COVID-19 patients. Proximal tubular dysfunction (PTD) and changes in urinary biomarkers, such as NGAL, TIMP-2, and IGFBP7 product ([TIMP-2]•[IGFBP7]), could precede AKI. We conducted a prospective cohort study from 2020/03/09 to 2020/05/03, which consecutively included all COVID-19 patients who had at least one urinalysis, to assess the incidence of PTD and AKI, and the effectiveness of PTD, NGAL, and [TIMP-2]•[IGFBP7] in AKI and persistent AKI prediction using the area under the receiver operating characteristic curves (AUCs), Kaplan-Meier methodology (log-rank tests), and Cox models. Among the 60 patients admitted to the ICU with proven COVID-19 (median age: 63-year-old (interquartile range: IQR, 55-74), 45 males (75%), median simplified acute physiology score (SAPS) II: 34 (IQR, 22-47) and median BMI: 25.7 kg/m2 (IQR, 23.3-30.8)) analyzed, PTD was diagnosed in 29 patients (48%), AKI in 33 (55%) and persistent AKI in 20 (33%). Urinary NGAL had the highest AUC for AKI prediction: 0.635 (95%CI: 0.491-0.779) and persistent AKI prediction: 0.681 (95%CI: 0.535-0.826), as compared to PTD and [TIMP-2]•[IGFBP7] (AUCs <0.6). AKI was independently associated with higher SAPSII (HR = 1.04, 95%CI: 1.01-1.06, p = 0.005) and BMI (HR = 1.07, 95%CI: 1.00-1.14, p = 0.04) and persistent AKI with higher SAPSII (HR = 1.03, 95%CI: 1.00-1.06, p = 0.048) and nephrotoxic drug use (HR = 3.88, 95%CI: 1.20-12.5, p = 0.02). In conclusion, in critically ill COVID-19 patients, the incidence of PTD and AKI was relatively high. NGAL was the best urinary biomarker for predicting AKI, but only clinical severity was independently associated with its occurrence.

Epidemiology and outcomes of post-AKI proteinuria

Background

Acute kidney injury (AKI) has been associated with increased risks of new-onset and worsening proteinuria. However, epidemiologic data for post-AKI proteinuria was still lacking. This study aimed to determine the incidence, risk factors and clinical correlations of post-AKI proteinuria among hospitalized patients.

Methods

This study was conducted in a multicenter cohort including patients aged 18-100 years with hospital-acquired AKI (HA-AKI) hospitalized at 19 medical centers throughout China. The primary outcome was the incidence of post-AKI proteinuria. Secondary outcomes included AKI recovery and kidney disease progression. The results of both quantitative and qualitative urinary protein tests were used to define post-AKI proteinuria. Cox proportional hazard model with stepwise regression was used to determine the risk factors for post-AKI proteinuria.

Results

Of 6206 HA-AKI patients without proteinuria at baseline, 2102 (33.9%) had new-onset proteinuria, whereas of 5137 HA-AKI with baseline proteinuria, 894 (17.4%) had worsening proteinuria after AKI. Higher AKI stage and preexisting CKD diagnosis were risk factors for new-onset proteinuria and worsening proteinuria, whereas treatment with renin-angiotensin system inhibitors was associated with an 11% lower risk of incident proteinuria. About 60% and 75% of patients with post-AKI new-onset and worsening proteinuria, respectively, recovered within 3 months. Worsening proteinuria was associated with a lower incidence of AKI recovery and a higher risk of kidney disease progression.

Conclusions

Post-AKI proteinuria is common and usually transient among hospitalized patients. The risk profiles for new-onset and worsening post-AKI proteinuria differed markedly. Worsening proteinuria after AKI was associated with adverse kidney outcomes, which emphasized the need for close monitoring of proteinuria after AKI.

Cystatin C in addition to creatinine for better assessment of glomerular renal function decline in people with HIV receiving antiretroviral therapy

OBJECTIVE

To compare the estimated glomerular filtration rate (eGFR) using the creatinine equation (eGFRcreat) or the cystatin C equation (eGFRcys) in people with HIV (PWH) under antiretroviral drugs. We specifically included patients with an eGFRcreat around 60 ml/min per 1.73 m2 to evaluate agreement on stage 2 and 3 chronic kidney disease (CKD) classification.

DESIGN

eGFRcreat, eGFRcys and resulting CKD staging were determined in 262 consecutive patients with HIV-1 (PWH) with a suppressed viral load (<200 copies/ml) under antiretroviral drugs and having impaired renal function (eGFRcreat between 45 and 80 ml/min per 1.73 m2). Antiretroviral drugs regimens were classified into eight groups: cobicistat (COBI)+elvitegravir (EVG), ritonavir (RTV)+protease inhibitor, dolutegravir (DTG), DTG+rilpivirine (RPV), RPV, raltegravir (RAL), bictegravir (BIC), and other antiretroviral drugs.

RESULTS

Mean eGFRcys was higher than mean eGFRcreat (77.7 ± 0.5 vs. 67.9  ± 7.9 ml/min per 1.73 m2, P < 0.0001). The differences were significant in five treatment groups with COBI/EVG; DTG; DTG+RPV; RPV; RAL. CKD classification was modified for 51% of patients when using eGFRcys instead of eGFRcreat, with reclassification to less severe stages in 37% and worse stages in 14%.

CONCLUSION

This study highlighted significant differences in eGFR depending on the renal marker used in PWH, having a significant impact on CKD classification. eGFRcys should be an additive tool for patients having eGFRcreat around 60 ml/min per 1.73 m2 for better identification of renal impairment.

Serial changes in renal indices in chronic HCV patients with and without HIV co-infection receiving sofosbuvir and tenofovir-based therapies

Background

Sofosbuvir (SOF) is authorized for hepatitis C virus (HCV) patients. The nephrotoxicity of SOF on HCV mono-infected and HCV–human immunodeficiency virus (HIV) individuals receiving antiretroviral therapy (ART) remains controversial.

Methods

A prospective study including 159 HCV mono-infected and 124 HCV–HIV individuals (47 were ART naïve and 77 were tenofovir [TDF]-based ART) who presented with an estimated glomerular filtration rate (eGFR) ≥30 ml/min/1.73 m2 at baseline and were treated with SOF–daclatasvir for 12 weeks. The eGFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration equation over the study period.

Results

HCV patients had a progressive decline in median levels of eGFR compared with HCV–HIV patients who were ART naïve and those receiving TDF-based ART during and after discontinuing SOF–DAC treatment (96, 109 and 114 at baseline vs 94, 117 and 108 at the end of treatment [EOT]) vs 95, 114 and 115 ml/min/1.73 m2 at 12 weeks after treatment [SVR12], respectively). Moreover, the rate of eGFR stage worsening was more pronounced in HCV mono-infected compared with HCV–HIV individuals who were ART naïve and those receiving TDF-based ART (21.4% vs 8.5% and 14.3% at EOT; 21.4% vs 2.1% and 6.5% at SVR12, respectively). Multivariable regression analysis showed that baseline variables were not independent predictors of eGFR stage worsening either at EOT or SVR12.

Conclusions

Because the changes in eGFR were minimal and not of clinical significance, and TDF was not associated with an increase in renal dysfunction, SOF-based direct-acting antivirals could be safely used in HCV mono-infected and HCV–HIV individuals, even in those on TDF-based ART.

Medium-grade proteinuria is a risk factor for incident markers of chronic kidney disease

OBJECTIVE

Medium-grade proteinuria (100-500 mg/g creatinine) is common among people living with HIV/AIDS (PLWHA) but is often undetected or ignored. This prospective, observational cohort study examined medium-grade proteinuria as a risk factor for markers of chronic kidney disease (CKD).

METHODS

Quantitative urine samples were collected from 241 PLWHA without known renal disease at baseline between January 2009 and February 2011 and at follow-up 240 weeks later. Multivariate analysis was performed to assess medium-grade proteinuria as a risk factor for incident markers of CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m² , albuminuria, phosphaturia).

RESULTS

Incident markers of CKD were identified in 33 patients (14%), of whom 24 (74%) had medium-grade proteinuria at baseline. Of these, 22 even had proteinuria of < 200 mg/g creatinine. Multivariate analysis showed an adjusted relative risk (aRR) of 2.4 for patients with baseline medium-grade proteinuria to develop signs of CKD. Age was identified as an additional independent predictor. By testing for interaction, tenofovir disoproxil fumarate (TDF)-independent proteinuria was strongly associated with incident CKD markers (aRR = 12.1).

CONCLUSION

Medium-grade proteinuria of 100-500 mg/g creatinine is both frequent in PLWHA and a significant risk factor for developing markers of CKD, especially in the absence of TDF. Relevant risk seems to be associated with proteinuria levels as low as 100-200 mg/g creatinine. Current guidelines recommend specific action for proteinuria exceeding 135-200 mg/g but still will miss a relevant number of PLWHA potentially at risk for CKD. An even lower cut-off to trigger nephrological work-up and potentially renoprotective interventions appears to be indicated.

Renal dysfunction among adult HIV/AIDS patients on antiretroviral therapy at a tertiary facility in Ghana

BACKGROUND

Kidney diseases have emerged as significant cause of morbidity and mortality in HIV subject on antiretroviral therapy (ART). In Ghana, routine follow up of HIV positive clients is by estimation of serum creatinine and urea levels. Glomerular Filtration Rate (GFR) is not routinely calculated and proteinuria is not routinely checked. This study sought to investigate the kidney profiles of adult HIV/AIDS patients being managed on ART at the Cape Coast Teaching Hospital (CCTH), Ghana.

METHODS

A hospital-based analytical cross sectional study with a retrospective component was conducted using systematic sampling method to recruit HIV/AIDS who visited the ART clinic. A total of 440 participants of both sexes aged 18 years and above, confirmed as HIV/AIDS positive and on ART were involved in this study. Blood and urine samples were collected from all subjects and the levels of serum creatinine and urea and proteinuria were estimated and eGFR calculated using the Modification of Diet in Renal Disease (MDRD) equations. Data analyses were performed using Stata version 13 software (Stata Corp, Texas USA).

RESULTS

The mean age (years) of participants was 45.5 years (±11.6) with 288 (65.4%) being on Tenofovir based ART regimen. The mean eGFR was found to decrease from 112.4 ml/min/1.73 m at baseline, to 103.4 ml/min/1.73 m after 6 months on ART and to a mean of 99.4 ml/min/1.73 m at recruitment into this study. Factors which were found to be associated with having eGFR < 60 included age, gender and CD4 count though not statistically significant. Patients > 45 years had the highest odds with OR 2.0 (95% CI: 0.8-5.1), females had higher odds with OR 1.5 (95% CI: 0.5-5.2), and those with CD4 count > 350 had OR of 0.4 (95% CI 0.2-1.3). A total of 30.9% of the participants had proteinuria at recruitment. TDF based ART regimen had no statistically significant effect on serum creatinine and urea levels.

CONCLUSION

Estimated GFR decreased after 6 months among patients on ART despite normal serum creatinine and urea levels. This finding suggests that clients in care at HIV/ART clinics in Ghana may benefit from routine estimation of GFR and proteinuria.

Impact of interferon-free regimens on the glomerular filtration rate during treatment of chronic hepatitis C in a real-life cohort

Little data are available on renal toxicity exerted by direct-acting antivirals (DAAs) in real life. The aim of this study was to assess the impact of direct-acting antivirals against hepatitis C virus infection currently used in Spain and Portugal on the estimated glomerular filtration rate (eGFR) in clinical practise. From an international, prospective multicohort study, patients treated with DAAs for at least 12 weeks and with eGFR ≥30 mL/min per 1.73 m² at baseline were selected. eGFR was determined using the CKD-EPI formula. A total of 1131 patients were included; 658 (58%) were HIV/HCV-coinfected patients. Among the 901 patients treated for 12 weeks, median (interquartile range) eGFR was 100 (87-107) at baseline vs 97 (85-105) mL/min per 1.73 m² at week 12 of follow-up (FU12) post-treatment (P < .001). For HIV-coinfected subjects who received tenofovir plus a ritonavir-boosted HIV protease inhibitor (PI/r), baseline vs FU12 eGFR were 104 (86-109) vs 104 (91-110) mL/min per 1.73 m² (P = .913). Among subjects receiving ombitasvir/paritaprevir with or without dasabuvir, eGFR did not show any significant change. Of 1100 subjects with eGFR >60 mL/min per 1.73 m² at baseline, 22 (2%) had eGFR <60 mL/min per 1.73 m² at FU12, but none presented with eGFR <30 mL/min per 1.73 m² . In conclusion, eGFR slightly declines during therapy with all-oral DAAs and this effect persists up to 12 weeks after stopping treatment in subjects with normal to moderately impaired renal function, regardless of HIV status. Concomitant use of tenofovir plus PI/r does not seem to have an impact on eGFR.

Renal health after long-term exposure to tenofovir disoproxil fumarate (TDF) in HIV/HBV positive adults in Ghana

OBJECTIVES

The study assessed markers of renal health in HIV/HBV co-infected patients receiving TDF-containing antiretroviral therapy in Ghana.

METHODS

Urinary protein-to-creatinine ratio (uPCR) and albumin-to-protein ratio (uAPR) were measured cross-sectionally after a median of four years of TDF. At this time, alongside extensive laboratory testing, patients underwent evaluation of liver stiffness and blood pressure. The estimated glomerular filtration rate (eGFR) was measured longitudinally before and during TDF therapy.

RESULTS

Among 101 participants (66% women, median age 44 years, median CD4 count 572 cells/mm³) 21% and 17% had detectable HIV-1 RNA and HBV DNA, respectively. Overall 35% showed hypertension, 6% diabetes, 7% liver stiffness indicative of cirrhosis, and 18% urinary excretion of Schistosoma antigen. Tubular proteinuria occurred in 16% of patients and was independently predicted by female gender and hypertension. The eGFR declined by median 1.8 ml/min/year during TDF exposure (IQR -4.4, -0.0); more pronounced declines (≥ 5 ml/min/year) occurred in 22% of patients and were associated with receiving ritonavir-boosted lopinavir rather than efavirenz. HBV DNA, HBeAg, transaminases, and liver stiffness were not predictive of renal function abnormalities.

CONCLUSIONS

The findings mandate improved diagnosis and management of hypertension and suggest targeted laboratory monitoring of patients receiving TDF alongside a booster in sub-Saharan Africa.

Diagnostic challenges of kidney diseases in HIV-infected patients

INTRODUCTION

Chronic kidney disease (CKD) is a prevalent comorbidity in persons living with HIV infection (PLWH) associated with an increase in cardiovascular morbidity and all-cause mortality. Furthermore, early diagnosis of CKD is difficult in PLWH. Areas covered: We reviewed the main diagnostic tools for CKD in PLWH, and discussed their strengths and limits. We performed a literature search on PubMed to identify reviews and clinical trials dealing with attractive kidney biomarkers of CKD in PLWH, with the following key words: 'HIV AND kidney', 'HIV AND Kidney biomarkers', 'CKD AND Kidney biomarkers'. Expert commentary: Currently, CKD diagnosis is based on the estimation of Glomerular Filtration Rate (GFR), and measurement of proteinuria by urine protein/creatinine ratio (uPCR). These parameters are independent and complementary predictors of outcomes. GFR estimates are lacking in accuracy in PLWH. The best GFR estimate is CKD-EPI study equation. Moreover, low-grade proteinuria is associated with an increased risk of kidney disease progression in PLWH, and guidelines derived from the general population may lack sensitivity. Different biomarkers of kidney diseases like N-acetyl beta glucosaminidase (NAG), Kidney Injury Molecule-1 (KIM-1), and Alpha-1-microglobulin may predict kidney disease progression and mortality in PLWH. Others may help clinicians detect antiretroviral-induced tubulopathy, or predict cardiovascular events. More studies are needed to validate the routine use of these types of biomarkers.

Changes in Kidney Function and in the Rate of Tubular Dysfunction After Tenofovir Withdrawal or Continuation in HIV-Infected Patients

INTRODUCTION

Longitudinal data on the changes in kidney function and tubular abnormalities in case of tenofovir disoproxil fumarate (TDF) withdrawal or continuation are scarce.

METHODS

Prospective study of 228 patients receiving TDF, with 3 sequential determinations of serum creatinine, estimated glomerular filtration rate (eGFR), phosphatemia, and different urinary parameters (protein, albumin, phosphaturia, uricosuria, and glycosuria). Changes were analyzed in patients who interrupted TDF as compared to those who continued the same regimen. Proximal renal tubular dysfunction (PRTD) was defined as ≥2 tubular abnormalities.

RESULTS

After a median follow-up of 59.5 months, 78 patients (34%) had PRTD, mainly proteinuria (40%) and phosphaturia (61%), and time on TDF explains the severity of tubular alterations and eGFR slopes. In 35 switching patients, there was a rapid and significant eGFR improvement (median +4.1 ml/min per 1.73 m; P = 0.02), leading to a 39%-83% reduction in the prevalence of tubular abnormalities and of PRTD in less than 1 year (66%-39%). In comparison, 193 patients continuing the same regimen for 21.2 months had a small but significant and progressive eGFR decrease (-2.9 mL·min·1.73 m; P < 0.01), and a progressive rise in the prevalence of phosphaturia, uricosuria, and glycosuria (+9%-56%). In linear mixed-effect model, subsequent eGFR impairment was associated with proteinuria and time on TDF, and eGFR improvement with TDF discontinuation.

CONCLUSIONS

Our data support the role of use and time on TDF in eGFR decline and tubular dysfunction. In contrast, TDF withdrawal is followed by a rapid and significant, although partial, recovery of eGFR and tubular abnormalities.

Longitudinal Assessment of Proximal Tubular Dysfunction in HIV Seropositive and Seronegative Persons: Correlates and Implications

BACKGROUND

Proximal tubular dysfunction (PTD) is common in HIV-positive persons and has been associated with tenofovir disoproxil fumarate (TDF). However, few studies have assessed the natural history PTD in HIV-positive and -negative individuals, or the association of PTD with the subsequent trajectory of directly measured glomerular filtration rate (mGFR).

METHODS

We followed 192 HIV-positive and 100 HIV-negative, nondiabetic participants for 3 years. We measured 3 PTD markers (normoglycemic glycosuria, fractional excretion of phosphorus, and tubular proteinuria) and mGFR (by iohexol disappearance from serum) annually. We used univariate and multivariate generalized estimating equation logistic regression to identify factors associated with PTD across all visits and linear mixed effects models to assess the association between baseline PTD and mGFR slope.

RESULTS

Compared with HIV-negative participants, HIV-positive persons that were not taking antiretroviral therapy were at increased risk of PTD (adjusted odds ratio 3.33; 95% confidence interval: 1.65 to 6.71), whereas those taking a TDF-based or a TDF-sparing regimen were not at significantly increased risk of PTD. Among HIV-positive participants, uncontrolled viremia was a strong correlate of PTD. Forty-nine of 55 (89%) participants with PTD at baseline had at least 1 subsequent visit without PTD. There was no association between baseline PTD and rate of decline in mGFR over time.

CONCLUSIONS

Poorly controlled HIV may be a stronger risk factor for PTD than TDF use. The individual-level variability of the PTD markers over time was high, potentially limiting their usefulness for routine screening in unselected patients. Baseline PTD was not associated with subsequent mGFR slope.

Absence of Decline of Kidney Function in Human Immunodeficiency Virus-Infected Patients Under Routine Clinical Management

BACKGROUND

Since the introduction of antiretroviral therapy (ART), human immunodeficiency virus (HIV)-infected patients have a drastically improved prognosis but at the same time they are also more affected by non-HIV related complications, such as chronic kidney disease. The objective of our study was to investigate the effect of proteinuria and tenofovir (TDF)-containing ART regimens on the temporal evolution of estimated glomerular filtration rate (eGFR).

METHODS

Between April 2008 and October 2012, we enrolled 395 patients with a complete renal evaluation among patients from the ANRS C03 Aquitaine cohort, a prospective hospital-based cohort of HIV-1-infected patients under routine clinical management in southwestern France. eGFR was estimated at each patient follow-up visit. A linear mixed model was used to analyze eGFR dynamics, accounting for change in TDF by modeling eGFR trajectory according to treatment periods.

RESULTS

At inclusion, 56.7% of patients were treated with TDF-containing ART regimens; prevalence of glomerular and tubular proteinuria was 7.9 and 10.8% respectively. A 1-year increase of cumulative exposure to TDF was significantly associated with a mean eGFR decrease of 1.27 mL/min/1.73 m2 (95% CI [-2.14 to -0.41]). Only a urine protein to creatinine ratio >100 mg/mmol and/or a urine albumin to creatinine ratio >70 mg/mmol were associated with eGFR trajectory (mean slope 6.18 mL/min/1.73 m2 per year; 95% CI [2.71 to 9.65]), whereas TDF use was not associated with such eGFR temporal evolution.

CONCLUSION

Decline in kidney function is limited under routine clinical management with monitoring of renal function and interventions including decision to continue or discontinue TDF.

Evolution of renal function in African patients initiating second-line antiretroviral treatment: findings from the ANRS 12169 2LADY trial

BACKGROUND

To investigate change in renal function in African patients initiating second-line antiretroviral therapy (ART) including ritonavir-boosted protease inhibitor (PI/r) with or without tenofovir disoproxil fumarate (TDF).

METHODS

HIV-1-positive adults, failing standard first-line ART were randomized to either TDF/emtricitabine (FTC)+LPV/r, abacavir + didanosine +LPV/r or TDF/FTC+ darunavir (DRV)/r and followed for 18 months. Patients with an estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m² at baseline were included in this analysis.

RESULTS

Data from 438 out of 454 randomized patients were analysed. Median age was 38 years and 72% were women. Initiation of PI/r-based second-line regimen induced a marked eGFR decline of -10.5 ml/min/1.73 m² at week 4 in all treatment groups with a greater decrease in TDF/FTC+LPV/r arm (-15.1 ml/min/1.73 m²). At month 18, mean eGFR in the non-TDF containing regimen recovered its baseline level and was significantly greater than eGFR 18-month levels in the TDF-containing regimens that experienced only partial recovery (difference: -10.7; CI -16.8, -4.6; P=0.001 in TDF/FTC+LPV/r and -6.4; CI -12.5, -0.3; P=0.04 in TDF/FTC+DRV/r). At 18 months, prevalence of stage 3 chronic kidney disease was low (<3%) and not associated with treatment. One treatment discontinuation and five TDF dosage reductions for renal toxicities were reported in TDF-containing arms.

CONCLUSIONS

Overall, these results suggest a reasonable renal tolerance of a regimen associating TDF/FTC+PI/r in African patients with eGFR>60 ml/ml/1.73 m² at baseline. They also support the recommendation of reassessing renal function 1 month after initiation of treatment including ritonavir to account for the ritonavir-related artefactual decrease of eGFR and determine the new reference baseline value.

Impact of protease inhibitors on the evolution of urinary markers: Subanalyses from an observational cross-sectional study

Kidney injury (defined as the presence of albuminuria, proteinuria, glycosuria [without hyperglycemia], hematuria, and/or renal hypophosphatemia) is an emerging problem in human immunodeficiency virus (HIV)-infected patients, although few data are available on the role of protease inhibitors (PIs) in this condition.To determine the time to kidney injury in a cohort of HIV-infected patients receiving a PI-containing regimen.We report the results of a subanalysis of a published cross-sectional study. The subanalysis included only patients receiving PI-containing regimens for more than 6 months (377 of the overall 970 patients). We determined associated factors and constructed receiver operating characteristic curves to estimate time to kidney injury depending on the PI used.The percentage of patients with kidney injury was 27.7% for darunavir, 27.9% for lopinavir, and 30% for atazanavir. Time to kidney injury was as follows: 229 days for atazanavir/ritonavir (area under the curve [AUC], 0.639; sensitivity, 0.89; specificity, 0.41); 332 days for atazanavir/ritonavir plus tenofovir (AUC, 0.603; sensitivity, 0.75; and specificity, 0.29); 318 days for nonboosted atazanavir (AUC, 0.581; sensitivity, 0.89; and specificity, 0.29); 478 days for lopinavir/ritonavir (AUC, 0.566; sensitivity, 0.864; and specificity, 0.44); 1339 days for lopinavir/ritonavir plus tenofovir (AUC, 0.667; sensitivity, 0.86; and specificity, 0.77); 283 days for darunavir/ritonavir (AUC, 0.523; sensitivity, 0.80; and specificity, 0.261); and 286 days for darunavir/ritonavir plus tenofovir (AUC, 0.446; sensitivity, 0.789; and specificity, 0.245). The use of lopinavir/ritonavir without tenofovir was a protective factor (odds ratio = 1.772; 95%CI, 1.070-2.93; P = 0.026).For all PIs, the percentage of patients with kidney injury exceeded 27%, irrespective of tenofovir use. The longest time to kidney injury was recorded with lopinavir/ritonavir. These results demonstrate the need for renal monitoring, including urine samples, in patients receiving a PI-based regimen, even when tenofovir is not used concomitantly.

Medium-grade tubular proteinuria is common in HIV-positive patients and specifically associated with exposure to tenofovir disoproxil Fumarate

OBJECTIVES

The aim of this cross-sectional study was to evaluate the prevalence and risk factors of medium-grade proteinuria (100-500 mg/g creatinine) among HIV-positive adults.

METHODS

Spot urine samples of HIV-positive adults without known renal disease were analyzed quantitatively between January 2009 and February 2011. Demographic and medical data were collected. Multivariate regression models for different patterns of proteinuria were constructed.

RESULTS

Among 411 patients, 18 (4.4 %) presented albuminuria >300 mg/g creatinine and/or proteinuria >500 mg/g creatinine and were excluded from further analyses. Among the study population of 393 patients, 181 (46.1 %) had no significant proteinuria or albuminuria (<100 and <30 mg/g creatinine, respectively), 60 (15.3 %) had moderate albuminuria, while 152 (38.7 %) had proteinuria without albuminuria, suggesting tubular proteinuria. Independent predictors for medium-grade tubular proteinuria in multivariate analysis were exposure to tenofovir (DF), a CD4 nadir <500/µl, older age, and anti-HCV-antibodies. There was no association with classic renal risk factors like diabetes mellitus and arterial hypertension, or with estimated glomerular filtration rate (eGFR).

CONCLUSIONS

We detected significant proteinuria in 230 (56.0 %) of 411 HIV-positive patients. Among this group, 152 (66.1 %) had medium-grade proteinuria without albuminuria, which was significantly associated with exposure to tenofovir, older age, a lower CD4 nadir and Hepatitis C. Nephrologic or HIV treatment guidelines fail to detect most of these patients but rather identify patients with high cardiovascular risk. In the absence of an association with eGFR the role of medium-grade tubular proteinuria as a potential early marker of chronic kidney disease remains unclear. Prospective studies are needed.

Tenofovir is associated with increased tubular proteinuria and asymptomatic renal tubular dysfunction in Ghana

BACKGROUND

HIV infection is associated with increased risk of renal dysfunction, including tubular dysfunction (TD) related to antiretroviral therapy (ART). Tenofovir disoproxil fumarate (TDF) is becoming available for ART in sub-Saharan Africa, although data on its long-term safety there is limited. We aimed to study the prevalence of HIV-associated renal dysfunction in Ghana and explore associations between proteinuria or TD and potential risk factors, including TDF use.

METHODS

A single-centre cross-sectional observational study of patients taking ART was undertaken. Creatinine clearance (CrCl) was calculated and proteinuria detected with dipsticks. Spot urinary albumin and protein:creatinine ratios (uACR/uPCR) were measured and further evidence of TD (defined as having two or more characteristic features) sought. Logistic regression analysis identified factors associated with proteinuria or TD.

RESULTS

In 330 patients, of whom 101 were taking TDF (median 20 months), the prevalence of CrCl < 60 ml/min/1.73 m(2), dipstick proteinuria and TD was 7 %, 37 % and 15 %. Factors associated with proteinuria were baseline CD4-count [aOR 0.86/100 cell increment (95 % CI, 0.74-0.99)] and TDF use [aOR 2.74 (95 % CI, 1.38-5.43)]. The only factor associated with TD was TDF use [aOR 3.43 (95 % CI, 1.10-10.69)]. In a subset with uPCR measurements, uPCRs were significantly higher in patients taking TDF than those on other drugs (10.8 vs. 5.7 mg/mmol, p < 0.001), and urinary albuin:protein ratios significantly lower (0.24 vs. 0.58, p < 0.001).

CONCLUSIONS

Both proteinuria and TD are common and associated with TDF use in Ghana. Further longitudinal studies to determine whether proteinuria, TD or TDF use are linked to progressive decline in renal function or other adverse outcomes are needed in Africa.

Long-Term Follow-Up of Proteinuria and Estimated Glomerular Filtration Rate in HIV-Infected Patients with Tubular Proteinuria

Objective

The objective of this prospective observational study was to describe the evolution of tubular proteinuria detected in HIV-infected patients, and to evaluate the impact of tenofovir disoproxil fumarate (TDF) discontinuation.

Methods

Proteinuria and estimated glomerular filtration rate (eGFR) were followed during a median duration of 32 months, in 81 HIV-infected patients with tubular proteinuria and eGFR ≥ 60 ml/min/1.73 m² (determined using the Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration equation). Tubular proteinuria was defined by urine protein to creatinine ratio (uPCR) ≥200 mg/g and albumin to protein ratio (uAPR) <0.4.

Results

Twenty per cent of patients had persistence of tubular proteinuria: TDF continuation was the main factor associated with this persistence [OR 9.0; 95%CI: 1.9–41.4; p = 0.01]. Among the 23 patients who discontinued TDF, uPCR returned below the threshold of 200 mg/g in 11 patients. Overall, eGFR decreased with a mean rate of decline of 3.8 ml/min/1.73m²/year. The decline in eGFR was lesser after discontinuation of TDF (5.8 ml/min/1.73m²/year during TDF exposure versus 3 ml/min/1.73m²/year after TDF discontinuation; p = 0.01).

Conclusions

The continuation of TDF was the main factor associated with the persistence of proteinuria. Moreover, proteinuria was normalized in only half of the patients who discontinued TDF. The clinical significance of TDF-related low level of proteinuria as a factor associated with renal disease progression and bone loss remains poorly understood.

Urine alpha1-microglobulin is a better marker for early tubular dysfunction than beta2-microglobulin among tenofovir-exposed human immunodeficiency virus-infected men who have sex with men

OBJECTIVES

Men who have sex with men are at risk of tenofovir nephrotoxicity due to its wide use in both treatment and prophylaxis for human immunodeficiency virus infection, but little is known about the urinary biomarkers of early renal dysfunction in this population. This study aims to identify useful biomarkers of early renal dysfunction among human immunodeficiency virus-infected men who have sex with men exposed to tenofovir.

METHODS

In a cross-sectional study urinary alpha1-microglobulin, beta2-microglobulin, N-acetyl-β-d-glucosaminidase and albumin were measured and expressed as the ratio-to-creatinine in 239 human immunodeficiency virus-infected men who have sex with men who were treatment naïve or receiving antiretroviral therapy with tenofovir-containing or non-tenofovir-containing regimens. Additionally, 56 patients in the non-antiretroviral therapy group started a tenofovir-containing regimen and were assessed after 3 and 6 months on antiretroviral therapy.

RESULTS

Both the frequency of alpha1-microglobulin proteinuria (alpha1-microglobulin-creatinine ratio >25.8mg/g) and the median urinary alpha1-microglobulin-creatinine ratio were higher in the tenofovir disoproxil fumarate group than the other two groups (all p<0.05). A higher frequency of beta2-microglobulin proteinuria (beta2-microglobulin-creatinine ratio >0.68mg/g) was also observed in the tenofovir group (28.9%) compared to the non-tenofovir group (13.6%, p=0.024). There were no significant differences between groups for N-acetyl-β-d-glucosaminidase and albumin. In the longitudinal study, the median urinary alpha1-microglobulin-creatinine ratio after 3 and 6 months on tenofovir-containing therapy (16.8 and 17.3mg/g) was higher than baseline (12.3mg/g, p=0.023 and 0.011, respectively), while no statistically important changes were observed in urinary beta2-microglobulin-creatinine ratio or in the other biomarkers after 3 and 6 months on antiretroviral therapy (all p>0.05).

CONCLUSION

Urinary alpha1-microglobulin seems to be a more sensitive and stable indicator of tubular dysfunction than urinary beta2-microglobulin for assessing tenofovir-related nephrotoxicity and can be significantly altered after tenofovir exposure.

A consensus statement on the renal monitoring of Australian patients receiving tenofovir based antiviral therapy for HIV/HBV infection

A number of antiviral agents used against Human Immunodeficiency Virus (HIV) infection and hepatitis B virus (HBV) mono or co-infection have been associated with real nephrotoxicity (including tenofovir disoproxil fumarate (TDF), atazanavir, indinavir and lopinavir) or apparent changes in renal function (e.g. cobicistat, ritonavir, rilpivirine and dolutegravir). Patients with HIV are at higher risk of acute and chronic renal dysfunction, so baseline assessment and ongoing monitoring of renal function is an important part of routine management of patients with HIV.

Given the paucity of evidence in this area, we sought to establish a consensus view on how routine monitoring could be performed in Australian patients on ART regimens, especially those involving TDF. A group of nephrologists and prescribers (an HIV physician and a hepatologist) were assembled by Gilead to discuss practical and reasonable renal management strategies for patients particularly those on TDF-based combination regimens (in the case of those with HIV-infection) or on TDF-monotherapy (in the case of HBV-mono infection). The group considered which investigations should be performed as part of routine practice, their frequency, and when specialist renal referral is warranted. The algorithm presented suggests testing for serum creatinine along with plasma phosphate and an assessment of urinary protein (rather than albumin) and glucose.

Here we advocate baseline tests of renal function at initiation of therapy. If creatinine excretion inhibitors (e.g. cobicistat or rilpivirine) are used as part of the ART regimen, we suggest creatinine is rechecked at 4 weeks and this value used as the new baseline. Repeat testing is suggested at 3-monthly intervals for a year and then at least yearly thereafter if no abnormalities are detected. In patients with abnormal baseline results, renal function assessment should be performed at least 6 monthly. In HBV mono-infected patients advocate that a similar testing protocol may be logical.

The role of albuminuria in the follow-up of HIV-infected pediatric patients

BACKGROUND

In HIV-infected adults, elevated albumin has been associated with increased inflammatory activity, HIV-related nephropathy, and type 2 diabetes. Data on albuminuria in HIV-infected children are very scarce, and guidelines do not include routine determination of urinary albumin/creatinine ratio in this population.

METHODS

We performed a cross-sectional study in a cohort of HIV-infected pediatric patients. Urinary protein/creatinine and albumin/creatinine ratios and hematuria were determined from at least three morning urine samples, and glomerular filtration rate (GFR) was estimated from creatinine levels. Persistent renal damage was defined according to the presence of at least two sequentially abnormal values in one of the parameters. The relationship between renal damage, HIV-related variables, and metabolic comorbidities (dyslipidemia, fat redistribution, glucose intolerance, hypertension) was investigated.

RESULTS

Symptom-free renal damage was observed in 13 of 68 patients (19.1%) and mainly consisted of persistent proteinuria (17.6%); glomerular proteinuria was twice as prevalent as tubular proteinuria. GFR were normal in all cases. No relationship between renal markers and HIV-related variables or metabolic comorbidities was observed.

CONCLUSIONS

Mild proteinuria affected approximately one fifth of patients in our cohort. The determination of albuminuria allowed the differentiation between glomerular and tubular proteinuria, although no relationship with metabolic comorbidities was observed.

Low-grade proteinuria is highly prevalent in HIV-positive patients on antiretroviral treatment

OBJECTIVES

HIV-positive patients are at an increased risk for chronic kidney disease. However, these data mainly derive from cohorts with a high percentage of African-American patients, representing a specific ethnical risk group for chronic kidney disease. The aim of this study was to estimate the prevalence and risk factors specifically for early signs of kidney dysfunction in a large, predominantly white cohort of HIV patients.

DESIGN

Cross-sectional study.

METHODS

Prevalence of low-grade proteinuria was measured by quantitative analysis of urinary protein-to-creatinine ratio (cutoff >70 mg/g) and further differentiated by assessing α1-microglobulin (tubular proteinuria) and albumin-to-creatinine ratio (glomerular proteinuria) of HIV patients attending the University Hospital in Cologne, Germany. Together with standard and HIV-related laboratory findings and medical history, risk factors for each form of proteinuria were identified using multivariate forward selection.

RESULTS

Of 945 enrolled patients, 55% were identified with low-grade proteinuria, 41% with tubular proteinuria, and 20% with glomerular proteinuria. Older age was a risk factor for all forms of proteinuria in multivariate analysis. Low-grade proteinuria was also associated with concomitant diabetes and exposure to nucleoside reverse transcriptase inhibitor [anytime during HIV infection, not tenofovir (TDF)-specific], whereas tubular proteinuria was linked to current and any exposure to nucleoside reverse transcriptase inhibitor (TDF-specific). Further risk factors for glomerular proteinuria were hypertension and diabetes in this cohort.

CONCLUSION

Low-grade, glomerular and tubular proteinuria are highly prevalent in this large white HIV cohort. Older age represents a nonmodifiable risk factor for all forms of proteinuria. Glomerular proteinuria is associated with modifiable cardiovascular, but not HIV-related risk factors, whereas tubular proteinuria is linked to TDF exposure.