Factors influencing kidney transplantation rates: a study from the ERA Registry

BACKGROUND

Large international differences exist in kidney transplantation (KT) rates. We aimed to investigate which factors may explain the total, deceased donor, and living donor KT rates over the last decade.

METHODS

KT experts from 39 European countries completed the Kidney Transplantation Rate Survey on measures and barriers and their potential effect on the KT rate in their country. In the analyses, countries were divided into low, middle, and high KT rate countries based on the KT rate at the start of study period in 2010.

RESULTS

Experts from low KT rate countries reported more frequently to have taken measures regarding staff, equipment and facilities to increase total KT rate compared with middle and high KT rate countries. For donor type specific KT, the largest international differences in measures taken were reported for deceased donor KT, with middle and high KT rate countries taking more measures, such as the use of expanded criteria donor kidneys, the presence of transplantation coordinators, and (inter)national exchange of donor kidneys. Once a measure was taken, experts' opinion on its success was similar across the low, middle and high KT rate countries. Experts from low KT rate countries more often reported potential barriers, such as patients' lack of knowledge and distrust in the health care system.

CONCLUSIONS

In particular in low KT rate countries, KT rate might be stimulated by optimizing staff, equipment, and facilities. In addition, all countries may benefit from deceased and living donor specific measures.

Aetiology, clinical features, diagnostic studies, and outcomes of community-acquired pneumonia in kidney transplant recipients admitted to hospital: a multicentre retrospective French cohort study

OBJECTIVES

To assess the aetiology, clinical features, diagnostic studies and outcomes of community-acquired pneumonia (CAP) in a French cohort of hospitalized kidney transplant recipients.

METHODS

We performed a retrospective, multicentre study in kidney transplant recipients admitted to ten French centres for CAP from January 2016 to December 2018. CAP discharge diagnoses were clinically and radiologically validated. We assessed a descriptive analysis of all confirmed CAP including medical ward and intensive care unit admissions.

RESULTS

One hundred sixty-five CAP episodes in 132 patients were included. Median time from transplantation to admission was 6.4 (interquartile range, 1.6-12.3) years, with corticosteroid exposure in 112/165 (67.9%) cases. Sputum culture was performed in 47/165 (28.5%) cases including 7/47 (14.9%) positive samples. Bronchoscopy was performed in 87/165 (52.7%) cases with pathogens identified in 39/87 (44.8%) cases. Microbiological studies led to identifying a respiratory pathogen in 64/165 (38.8%) CAP episodes including 11/64 (17.2%) polymicrobial cases. Among these 64 episodes, 75 microorganisms were identified; 46/75 (61.3%) were core respiratory pathogens and 29/75 (38.7%) were opportunistic or drug-resistant organisms including Pneumocystis jirovecii 9/75 (12%), Pseudomonas aeruginosa 5/75 (6.7%), multidrug-resistant Enterobacteriaceae 4/75 (5.3%), and Aspergillus 4/75 (5.3%). Patients required intensive care unit admission in 26/165 (15.8%) episodes, invasive ventilation in 20/165 (12.1%) cases, and 22/165 (13.3%) needed in-hospital dialysis.

DISCUSSION

CAP episodes occurred in kidney transplant recipients with a long history of immunosuppressive drug exposure. Diagnostic studies identified a microorganism in more than one-third of CAP episodes, including drug-resistant and opportunistic pathogens.

Barriers to conservative care from patients' and nephrologists' perspectives: the CKD-REIN study

BACKGROUND

Conservative care is increasingly considered an alternative to kidney replacement therapy for kidney failure management, mostly among the elderly. We investigated its status and the barriers to its implementation from patients' and providers' perspectives.

METHODS

We analysed data from 1204 patients with advanced chronic kidney disease (CKD) [estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2] enrolled at 40 nationally representative nephrology clinics (2013-16) who completed a self-administered questionnaire about the information they received and their preferred treatment option, including conservative care, if their kidneys failed. Nephrologists (n = 137) also reported data about their clinics' resources and practices regarding conservative care.

RESULTS

All participating facilities reported they were routinely able to offer conservative care, but only 37% had written protocols and only 5% had a person or team primarily responsible for it. Overall, 6% of patients were estimated to use conservative care. Among nephrologists, 82% reported they were fairly or extremely comfortable discussing conservative care, but only 28% usually or always offered this option for older (>75 years) patients approaching kidney failure. They used various terminology for this care, with conservative management and non-dialysis care mentioned most often. Among patients, 5% of those >75 years reported receiving information about this option and 2% preferring it.

CONCLUSIONS

Although reported by nephrologists to be widely available and easily discussed, conservative care is only occasionally offered to older patients, most of whom report they were not informed of this option. The lack of a person or team responsible for conservative care and unclear information appear to be key barriers to its implementation.

Five-Year Symptom Trajectories in Nondialysis-Dependent CKD Patients

BACKGROUND AND OBJECTIVES

Late stages of CKD are characterized by significant symptom burden. This study aimed to identify subgroups within the 5-year trajectories of symptom evolution in patients with CKD and to describe associated patient characteristics and outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Among 2787 participants (66% men) with eGFR <60 ml/min per 1.73 m2 enrolled in the CKD-Renal Epidemiology and Information Network (CKD-REIN) cohort study from July 2013 to May 2016, we assessed symptoms annually using the Kidney Disease Quality of Life-36 (KDQOL-36) questionnaire until December 2020. A total of 9121 measures were reported over follow-up; all participants had symptoms scored for at least one time point. We used a joint latent class-mixed model to distinguish profiles of symptom trajectories.

RESULTS

Patient mean age (±SD) at baseline was 67±13 years, and mean eGFR was 33±13 ml/min per 1.73 m2. The prevalence of each symptom ranged from 24% (chest pain) to 83% (fatigue), and 98% of participants reported at least one symptom. After a median (interquartile range) follow-up of 5.3 (3.4-6.0) years, 690 participants initiated KRT, and 490 died before KRT. We identified two profiles of symptom trajectories: a "worse symptom score and worsening trajectory" in 31% of participants, characterized by a low initial symptom score that worsened more than ten points over time, and a "better symptom score and stable trajectory" in 69% of participants, characterized by a high initial score that remained stable. Participants in the worse symptom score and worsening trajectory group had more risk factors for CKD progression at baseline, worse quality of life, and a higher risk of KRT and death before KRT than other participants.

CONCLUSIONS

This study highlights a significant worsening of symptoms in about one third of the participants, whereas the majority reported low symptom severity throughout the study.

Absence of Mortality Differences Between the First and Second COVID-19 Waves in Kidney Transplant Recipients

Introduction

SARS-CoV-2 pandemic evolved in 2 consecutive waves during 2020. Improvements in the management of COVID-19 led to a reduction in mortality rates among hospitalized patients during the second wave. Whether this progress benefited kidney transplant recipients (KTRs), a population particularly vulnerable to severe COVID-19, remained unclear.

Methods

In France, 957 KTRs were hospitalized for COVID-19 in 2020 and their data were prospectively collected into the French Solid Organ Transplant (SOT) COVID registry. The presentation, management, and outcomes of the 359 KTRs diagnosed during the first wave were compared to those of the 598 of the second wave.

Results

Baseline comorbidities were similar between KTRs of the 2 waves. Maintenance immunosuppression was reduced in most patients but withdrawal of antimetabolite (73.7% vs. 58.4%, P < 0.001) or calcineurin inhibitor (32.1% vs. 16.6%, P < 0.001) was less frequent during the second wave. Hydroxychloroquine and azithromycin that were commonly used during the first wave (21.7% and 30.9%, respectively) but were almost abandoned during the second wave. In contrast, the use of high dose corticosteroids doubled (19.5% vs. 41.6%, P < 0.001). Despite these changing trends in COVID-19 management, 60-day mortality was not statistically different between the 2 waves (25.3% vs. 23.9%; Log Rank, P = 0.48) and COVID-19 hospitalization period was not associated with death due to COVID-19 in multivariate analysis (Hazard ratio 0.89, 95% confidence interval 0.67–1.17, P = 0.4).

Conclusion

We conclude that changing of therapeutic trends during 2020 did not reduce COVID-19 related mortality among KTRs. Our data indirectly support the importance of vaccination and neutralizing monoclonal anti-SARS-CoV-2 antibodies to protect KTRS from severe COVID-19.

Association between kidney retransplantation and survival according to age in the French national cohort of dialysis patients

The mean age of patients returning to dialysis after a first kidney transplantation (KT) has increased in the past decades. We aimed to assess the association between second KT (2KT) and survival according to age at the time of return to dialysis. Data of 5334 patients registered in the French Renal Epidemiology and Information Network (REIN) (mean age 56.6 ± 13.6 years) who returned to dialysis after a first KT were collected. The association of 2KT with death was assessed using a propensity score-based analysis taking into account baseline and follow-up variables. In relisted patients (3272 patients, 61.3%), retransplantation was associated with better overall survival in comparison with patients who remained in dialysis (adjusted HR 0.75 [0.63-0.89], p = .0009). The survival advantage conferred by retransplantation gradually declined with increasing age (adjusted HR 0.41 [0.24-0.70] in patients <50, HR 0.94 (0.69-1.27) in patients aged 70 or older, p for interaction 0.034 for age considered as a continuous variable). 2KT is associated with better survival as opposed to remaining on dialysis after a first kidney graft failure. Nevertheless, this survival benefit is age dependent and diminishes with increasing age. The risk/benefit ratio should be comprehensively assessed in the oldest patients when relisting is considered.

[Nephrologist-IPA collaboration for better patient management]

Chronic kidney disease, the extreme consequence of which is dialysis or transplantation, requires a highly structured care pathway, marked by precise care and treatment recommendations. Given the aging of the population, the increase in the number of patients is inevitable. Synergy between nephrologists and advanced practice nurses allows the implementation of organization protocols in fields of competence including consultations and prescriptions.

Lack of Monitoring Is Associated with Risk of Acute Kidney Events among Patients with Inflammatory Bowel Disease

Background: Although the iatrogenic risk of kidney failure is infrequent with treatment for inflammatory bowel disease (IBD), the repercussions for the patient could be major. The aim of this study was to assess the incidence of kidney events in IBD and to examine the protective effect of kidney function monitoring. Methods: In the French National Health Insurance database, 94,363 patients had a diagnosis of IBD between January 2010 and December 2016. By using a survival model with time-dependent covariates, we analyzed the time from inclusion in this IBD cohort to the first hospitalization for acute kidney impairment (AKI) according to patient characteristics, comorbidities, IBD phenotype and presence of monitoring. Results: A total of 693 patients were hospitalized for AKI, with an incidence of 1.36/1000 person−years (95% confidence interval [CI] 1.26−1.47). The incidence of AKI was lower than those without 5-aminosalicylic acid (5-ASA) use. Patients with 5-ASA use rarely had any lack of monitoring as compared with those not under 5-ASA use (3% vs. 17%). On multivariate analysis, lack of monitoring was associated with a substantial risk of AKI (hazard ratio 3.96, 95% CI [3.20−4.90], p < 0.0001). Conclusions: Increased frequency of monitoring is essential to identify nephropathy at an early stage and avoid the progression to chronic kidney disease.

MO503: Cognitive Performance in Patients With Chronic Kidney Disease: Results From the CKD-Rein Cohort Study

BACKGROUND AND AIMS

Chronic kidney disease (CKD) is a risk factor for cognitive impairment. In the general population, many risk factors have been reported in association with incident major neurocognitive disorders. The link between CKD and cognitive dysfunction is not completely understood; it may involve different mechanisms such as vascular dysfunction or uremic toxin toxicity. We aimed to assess the influence of cardiovascular risk factors, cardiovascular disease and depression on the association between kidney function and cognitive function in patients with CKD.

METHOD

We analyzed baseline data from 3033 patients with CKD stage 3–5 included in the Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort between 2013 and 2016. Cognitive function was assessed with the Mini Mental State Examination (MMSE), and the glomerular filtration rate was estimated with the CKD EPI formula. We applied unadjusted and adjusted linear and logistic regression models, with the MMSE score as a continuous or categorical variable (at a cut-off point at 24/30).

RESULTS

The mean patient age was 66.8, the mean estimated glomerular filtration rate (eGFR) was 33 mL/min/1.73 m2 and 393 patients (13.0%) had a MMSE score &lt;24. We observed that, relative to patients with an MMSE score of 24 or more, patients with a score &lt;24 were older and more likely to be female and dependent on activities of daily living (ADL) and/or instrumental ADL. They were taking more medications and they were more affected by depressive symptoms as measured by the CES-D-10 (10 item Centre for Epidemiological Studies-Depression scale). Patients with a score &lt;24 were also more likely to present cardiovascular (CV) risk factors and CV comorbidities. They had a significantly higher parathyroid hormone level, lower haemoglobin, lower albumin and lower eGFR.

The eGFR was positively associated with the MMSE score before and after adjustment for age, sex, education level, cardiovascular risk factors, cardiovascular disease and depression, giving point increases in the MMSE score of 0.24 (0.15–0.33; P &lt; .001) and 0.14 (0.04–0.23; P = .006) for a 10 mL/min/1.73 m2 increment in the eGFR, respectively. Other risk factors significantly associated with a lower MMSE score in multivariate analysis were age, female sex, lower educational level, diabetes, obesity, cerebrovascular disease, atrial fibrillation and CES-D-10 score. The eGFR was associated with a low MMSE score (defined as MMSE score &lt;24/30) with a crude odds ratio (OR) of 0.82 (0.75–0.90), which remained significant at 0.88 (0.78–0.98) after adjustment for age, sex, educational level, cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidaemia, obesity and smoking), cardiovascular comorbidities (cerebrovascular disease, atrial fibrillation and heart failure), history of depression, laboratory parameters (haemoglobin and phosphate) and CES-D score (after imputation of missing values).

CONCLUSION

In a cohort of well-phenotyped patients with CKD, lower eGFR is associated with worse cognitive function, independent of age, sex, educational level, cardiovascular injury and depression.

MO496: Serum Urea Levels and Cardiovascular Disease in Patients With Chronic Kidney Disease

BACKGROUND AND AIMS

Elevated serum urea levels are common in moderate-to-advanced CKD. Several studies have shown that urea is a direct and indirect uremic toxin, especially with regard to cardiovascular disease. We sought to determine whether serum urea levels are associated with adverse cardiovascular events and death before kidney replacement therapy (KRT) in patients with CKD.

METHOD

CKD-REIN is a prospective cohort of CKD nephrology outpatients not receiving maintenance dialysis. The 2507 patients included in the analysis were divided into three groups according to the baseline serum urea level (T1 &lt; 10.5, T2:10.5–15.1 and T3 ≥ 15.1 mmol/L). Cause-specific Cox proportional hazard models were used to estimate hazard ratios (HRs) for the first atheromatous or nonatheromatous cardiovascular (CV) events and all-cause mortality before KRT. The models were adjusted for baseline comorbidities, laboratory data, and medications. Cardiovascular events of the first 3 years of follow-up in the CKD-REIN study were assessed carefully according to the Cardiovascular and Stroke Endpoint Definitions for Clinical Trials. Each death before KRT occurring during the 5-year follow-up period was used in the all-cause mortality model.

RESULTS

Of the 2507 included patients {median [first quartile–third quartile (Q1–Q3)] age: 69 (61–77); mean (standard deviation) eGFR 33.5(11.6) mL/min/1.73 m²}, 54% had a history of cardiovascular disease.

Over a median follow-up of 3.0 years [Q1–Q3, 2.2–3.1], 451 experienced their first atheromatous or nonatheromatous cardiovascular event (fatal or nonfatal), leading to an incidence rate (IR) [95% confidence interval (95% CI)] of 7.1 (6.4–7.7)/100 person-years (PYs) (Fig. 1).

Over a median follow-up period of 4.8 (3.3–5.1) years, 407 patients died before KRT, leading to an IR of 4.0 (3.6–4.3)/100 PYs.

After multiple adjustments for cardiovascular risk factors (including eGFR), patients in T3 had a higher risk of atheromatous and nonatheromatous cardiovascular events than patients in T1 [HR (95% CI), 2.08 (1.50–2.88), Fig. 1]. A nonsignificant trend towards a higher risk was also noted for patients in T2 [1.28 (0.96–1.71)]. The adjusted HRs for death before KRT were 1.30 (0.96–1.75] and 1.73 (1.22–2.45) for patients in T2 and those in T3, respectively.

CONCLUSION

Beyond CV risk factors including eGFR, this hypothesis-generating study suggests that serum urea level is a predictor of cardiovascular outcomes in patients with moderate to advanced CKD. Further research is needed to confirm current findings and explore mechanisms.

MO499: Incidence of Cause-Specific Cardiovascular Events in Men and Women With CKD

BACKGROUND AND AIMS

Men are at higher risk of cardiovascular disease (CVD) than women in the general population, and chronic kidney disease (CKD) is a well-established cardiovascular (CV) risk factor [1–4]. However, the incidence of cause-specific CV events in men and women with CKD is poorly documented.

METHOD

All hospitalization and death reports for CV events of the 3033 patients (1983 men and 1050 women) with non-dialysis CKD (stage 3–5) included in the French CKD-REIN Cohort were reviewed and classified by cause using criteria from the Cardiovascular and Stroke Endpoint Definitions for Clinical Trials [5]. Cause-specific Cox proportional hazard models were used to estimate hazard ratios for death and each fatal or nonfatal CV event according to gender.

RESULTS

At baseline, in men (mean age: 68 years; mean eGFR 33 mL/min/1.73 m²), the prevalence of atheromatous CVD was 30% for coronary artery disease, 14% for cerebrovascular disease and 17% for lower limb artery disease, and that of non-atheromatous CVD was 14% for heart failure and 13% for atrial fibrillation. In women (65 years old, 32 mL/min/1.73 m²), these prevalences were 15%, 7%, 9%, 11% and 9%, respectively.

During a median follow-up of 5 (IQR: 3–5) years, 98 men and 43 women died from CVD {i.e. 1.3 [95% confidence interval (95% CI): 1.0–1.5] versus 1.0 (0.7–1.3)/100 person-years}, including 53% versus 46% from heart failure, 31% versus 19% from sudden death, and 16% versus 35% from other cardiovascular causes, respectively.

Crude incidence rates of death or hospitalization for coronary artery disease and lower limb artery disease were higher in men than in women, slightly higher for CV death, cerebrovascular disease and atrial fibrillation, but similar for both genders for heart failure (Fig. 1). History of CVD was strongly associated with subsequent CV events of any type.

In multivariable analyses, gender was no longer associated with any cause-specific CV event, whereas a lower eGFR was significantly associated with an increased risk of coronary artery disease and heart failure, but not with other CV events (Table 1).

CONCLUSION

In patients with moderate or advanced CKD, the burden of atheromatous CVD is higher in men than in women and explained by their higher prevalence of cardiovascular risk factors, but that for heart failure and atrial fibrillation appears to be similar for both genders.

Probiotic Intake and Inflammation in Patients With Chronic Kidney Disease: An Analysis of the CKD-REIN Cohort

Background and Aims

Little is known about the effects of probiotics on inflammation in the context of chronic kidney disease (CKD). We investigated the association between probiotic intake and inflammation in patients with moderate-to-advanced CKD.

Methods

We performed a cross-sectional study of 888 patients with stage 3–5 CKD and data on serum C-reactive protein (CRP) levels and a concomitant food frequency questionnaire. We estimated the odds ratios (ORs) [95% confidence interval (CI)] for various CRP thresholds (>3, >4, >5, >6, and >7 mg/L) associated with three intake categories (no yoghurt, ordinary yoghurt, and probiotics from yoghurts or dietary supplements) and two frequency categories (daily or less than daily).

Results

The 888 study participants (median age: 70; men: 65%) had a median estimated glomerular filtration rate of 28.6 mL/min/1.73 m² and a median [interquartile range] CRP level of 3.0 [1.6, 7.0] mg/L. Fifty-seven percent consumed ordinary yoghurt and 30% consumed probiotic yoghurt. The median intake frequency for yoghurt and probiotics was 7 per week. Relative to participants not consuming yoghurt, the ORs [95% CI] for CRP > 6 or >7 mg/L were significantly lower for participants consuming ordinary yoghurt (0.58 [0.37, 0.93] and 0.57 [0.35, 0.91], respectively) and for participants consuming probiotics (0.54 [0.33, 0.9] and 0.48 [0.28, 0.81], respectively), independently of age, sex, body mass index, CKD stage, cardiovascular disease, and fibre, protein and total energy intakes. The ORs were not significantly lower for CRP thresholds >3, >4, and >5 mg/L and were not significantly greater in daily consumers than in occasional consumers.

Conclusion

We observed independent associations between the consumption of yoghurt or probiotics and lower levels of inflammation in patients with CKD. There was no evidence of a dose-effect relationship.

Clinical Trial Registration

[https://www.clinicaltrials.gov/ct2/show/NCT03381950], identifier [NCT03381950].

Impact of targeted hypothermia in expanded-criteria organ donors on recipient kidney-graft function: study protocol for a multicentre randomised controlled trial (HYPOREME)

INTRODUCTION

Expanded-criteria donors (ECDs) are used to reduce the shortage of kidneys for transplantation. However, kidneys from ECDs are associated with an increased risk of delayed graft function (DGF), a risk factor for allograft loss and mortality. HYPOREME will be a multicentre randomised controlled trial (RCT) comparing targeted hypothermia to normothermia in ECDs, in a country where the use of machine perfusion for organ storage is the standard of care. We hypothesise that hypothermia will decrease the incidence of DGF.

METHODS AND ANALYSIS

HYPOREME is a multicentre RCT comparing the effect on kidney function in recipients of targeted hypothermia (34°C-35°C) and normothermia (36.5°C-37.5°C) in the ECDs. The temperature intervention starts from randomisation and is maintained until aortic clamping in the operating room. We aim to enrol 289 ECDs in order to analyse the kidney function of 516 recipients in the 53 participating centres. The primary outcome is the occurrence of DGF in kidney recipients, defined as a requirement for renal replacement therapy within 7 days after transplantation (not counting a single session for hyperkalemia during the first 24 hours). Secondary outcomes include the proportion of patients with individual organs transplanted in each group; the number of organs transplanted from each ECD and the vital status and kidney function of the recipients 7 days, 28 days, 3 months and 1 year after transplantation. An interim analysis is planned after the enrolment of 258 kidney recipients.

ETHICS AND DISSEMINATION

The trial was approved by the ethics committee of the French Intensive Care Society (CE-SRLF-16-07) on 26 April 2016 and by the competent French authorities on 20 April 2016 (Comité de Protection des Personnes-TOURS-Région Centre-Ouest 1, registration #2016-S3). Findings will be published in peer-reviewed journals and presented during national and international scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03098706.

Urea levels and cardiovascular disease in patients with chronic kidney disease

BACKGROUND

Elevated serum urea levels are common in moderate-to-advanced CKD. Several studies have shown that urea is a direct and indirect uremic toxin, especially with regard to cardiovascular disease. We sought to determine whether serum urea levels are associated with adverse cardiovascular events and death before renal replacement therapy (RRT) in patients with CKD.

METHODS

CKD-REIN is a prospective cohort of CKD nephrology outpatients not receiving maintenance dialysis. The 2507 patients included in the analysis were divided into three groups according to the baseline serum urea level (T1 < 10.5, T2:10.5 to 15.1, and T3 ≥ 15.1 mmol/L). Cox proportional hazard models were used to estimate hazard ratios (HRs) for first atheromatous or nonatheromatous cardiovascular (CV) events, and all-cause mortality before RRT. The models were adjusted for baseline comorbidities, laboratory data, and medications.

FINDINGS

Of the 2507 included patients (median [interquartile range (IQR)] age: 69[61-77]; mean (standard deviation) eGFR 33.5(11.6) mL/min/1.73 m²), 54% had a history of cardiovascular disease. After multiple adjustments for cardiovascular risk factors (including eGFR), patients in T3 had a higher risk of atheromatous and nonatheromatous cardiovascular events than patient in T1 (n events = 451, HR[95%CI]: 1.93[1.39-2.69]). The adjusted HRs for death before RRT (n events = 407) were 1.31[0.97; 1.76] and 1.73[1.22; 2.45] for patients T2 and those in T3, respectively.

INTERPRETATION

Our data suggested that urea is a predictor of cardiovascular outcomes beyond CV risk factors including eGFR.

Effectiveness and Tolerance of Renin-Angiotensin System Inhibitors With Aging in Chronic Kidney Disease

OBJECTIVES

Renin-angiotensin system inhibitors (RASi) are recommended for slowing chronic kidney disease (CKD) progression to kidney failure. Their effectiveness and tolerance as patients age remain uncertain because older patients have often been excluded from clinical trials.

DESIGN

CKD-REIN cohort study.

SETTING AND PARTICIPANTS

We studied 2762 patients with CKD stages 3 and 4 and a clinical indication for RASi enrolled between 2013 and 2016 in 40 nephrology clinics nationally representative in France.

METHODS

The primary outcome was the occurrence of kidney failure or death. The secondary outcomes were the occurrence of cardiovascular events and hospitalizations with acute kidney injury (AKI) or hyperkalemia. A propensity score analysis was performed. We used Cox models to estimate hazard ratios (HRs) for each outcome associated with RASi prescription and tested interactions with age.

RESULTS

Patients' mean age was 67 years, including 841 (30%) aged 75 years and older; 2178 (79%) were prescribed RASi's. During a median follow-up of 4.6 years, 33% of patients reached kidney failure or died. RASi prescription was associated with a lower risk of kidney failure or death (HR 0.79, 95% CI 0.66, 0.95), an association not modified by age (P for interaction = .72). It was not significantly associated with cardiovascular events. During the first 3 years of follow-up, 14% of patients were hospitalized with AKI or hyperkalemia, but risk was not higher among those prescribed RASi's (HR 0.75, 95% CI 0.55-1.02) and age did not modify its effect (P for interaction = .28).

CONCLUSIONS AND IMPLICATIONS

This study shows that aging does not appear to modify either RASi's beneficial effects on major CKD outcomes or their potential adverse effects.

New Insights into Acute-on-Chronic Kidney Disease in Nephrology Patients: The CKD-REIN Study

BACKGROUND

Acute-on-chronic kidney disease (ACKD) is poorly understood and often overlooked. We studied its incidence, circumstances, determinants, and outcomes in patients with CKD.

METHODS

We used the Kidney Disease Improving Global Outcomes criteria to identify all-stage acute kidney injury (AKI) events in 3033 nephrology outpatients with CKD stage 3-5 participating in the CKD-REIN cohort study (2013-2020), and cause-specific Cox models to estimate hazard ratios (HR, 95% confidence intervals [CI]) of AKI-associated risk factors.

RESULTS

At baseline, 22% of the patients (mean age 67 years, 65% men, mean eGFR 32 ml/min/1.73m2) had a history of AKI. Over a 3-year follow-up, 443 had at least one AKI event: 27% were stage 2 or 3, and 11% required dialysis; 74% involved hospitalization including 47% acquired as hospital inpatients; a third were not reported in hospital discharge reports. Incidence rates were 10.1 and 4.8 per 100 person-years in patients with and without an AKI history, respectively. In 2375 patients without this history, male sex, diabetes, cardiovascular disease, cirrhosis, several drugs, low eGFR, and serum albumin levels were significantly associated with a higher risk of AKI, as were low birth weight (<2500 g) (adjusted HR, 1.98; 95%CI, 1.35 to 2.91) and hemoglobin level (HR 1.21; 1.12 to 1.32 per 1 g/dl decrease). Within one year, only 63% of the patients had recovered their previous kidney function, 13.7% had started kidney replacement therapy, and 12.7% had died.

CONCLUSIONS

The study highlights the high rate of hospital-acquired AKI events in patients with CKD, and their underreporting at hospital discharge. It also reveals low birth weight and anemia as possible new risk factors in CKD patients.

Knowledge of 5-aminosalicylic acid nephrotoxicity and adherence to kidney function monitoring of patients with inflammatory bowel disease

BACKGROUND AND AIM

5-Aminosalicylic acid (5-ASA) nephrotoxicity is a rare and idiosyncratic condition in patients with inflammatory bowel disease (IBD), which may lead to end-stage kidney failure. Kidney function monitoring is recommended in clinical practice to prevent this complication. However, no data is available regarding the knowledge and adherence of patients with IBD to this monitoring.

METHODS

As a part of routine practice, patients with IBD under treatment or previously treated with 5-ASA were systematically interviewed about knowledge of 5-ASA nephrotoxicity and adherence to kidney function monitoring. We reported here the experience among the first 103 consecutive patients seen in a French referral center.

RESULTS

A total of 103 patients (93.2% ulcerative colitis, 5.8% Crohn's disease, and 1% unclassified colitis) were analyzed. Among them, 70% were informed about the need for kidney function monitoring, and in most cases, information was provided by their gastroenterologist (94.4%). The adherence rate to monitoring was very high (84.7%). Monitoring consisted of serum creatinine and estimated glomerular filtration rate in most cases (97.2%), while 24-h proteinuria was less frequently used (69.4%). These tests were performed twice or ≥3 times per year by 44.4 and 41.7% of patients, respectively. One case of isolated elevation of proteinuria related to 5-ASA treatment was observed.

CONCLUSION

We reported for the first time that patients with IBD are well informed and adherent to kidney function monitoring of treatment with 5-ASA. The monitoring performed by their treating physician was generally in accordance with current recommendations.