Comparison of graft and patient survival according to the transplantation centre policy for 1-year screening biopsy among stable kidney recipients: a propensity score-based study.

BACKGROUND: The clinical utility of screening biopsies (SBs) at 1 year post-transplantation is still debated, especially for stable kidney graft recipients. Given the heterogeneity in practices between transplantation centres, the objective of this study was to compare graft and patient survival of stable patients according to whether they were followed up in a transplantation centre with or without a policy for having an SB at 1 year post-transplantation. MATERIALS: From a French multicentre cohort, we studied 1573 kidney recipients who were alive with stable graft function at 1 year post-transplantation, with no acute rejection in their first year post-transplantation. RESULTS: Using propensity score-based analyses, we did not observe any significant difference in the relative risk for graft failure between patients from centres with a 1-year SB policy and those from other centres [hazard ratio = 1.15, 95% confidence interval (CI) 0.86-1.53]. The corresponding adjusted survival probability at 8 years post-transplantation was 69% (95% CI 61-74%) for patients from centres with a 1-year SB policy versus 74% (95% CI 67-79%) for those from other centres. CONCLUSION: A 1-year SB policy for stable patients may not lead to therapeutical benefits for improved graft and patient survival. Further studies examining the benefits versus the risks of a 1-year SB policy are warranted to demonstrate the long-term utility of this intervention.

Dynamic predictions of long-term kidney graft failure: an information tool promoting patient-centred care.

BACKGROUND: Informing kidney transplant recipients of their prognosis and disease progression is of primary importance in a patient-centred vision of care. By participating in decisions from the outset, transplant recipients may be more adherent to complex medical regimens due to their enhanced understanding. METHODS: We proposed to include repeated measurements of serum creatinine (SCr), in addition to baseline characteristics, in order to obtain dynamic predictions of the graft failure risk that could be updated continuously during patient follow-up. Adult recipients from the French Données Informatisées et VAlidées en Transplantation (DIVAT) cohort transplanted for the first or second time from a heart-beating or living donor and alive with a functioning graft at 1 year post-transplantation were included. RESULTS: The model was composed of six baseline parameters, in addition to the SCr evolution. We validated the dynamic predictions by evaluating both discrimination and calibration accuracy. The area under the receiver operating characteristic curve varied from 0.72 to 0.76 for prediction times at 1 and 6 years post-transplantation, respectively, while calibration plots showed correct accuracy. We also provided an online application tool (https://shiny.idbc.fr/DynPG). CONCLUSION: We have created a tool that, for the first time in kidney transplantation, predicts graft failure risk both at an individual patient level and dynamically. We believe that this tool would encourage willing patients into participative medicine.

The 1-year Renal Biopsy Index: a scoring system to drive biopsy indication at 1-year post-kidney transplantation.

Surveillance biopsies after renal transplantation remain debatable. To drive the decision of such intervention, we propose a predictive score of abnormal histology at 1-year post-transplantation, named 1-year Renal Biopsy Index (1-RBI). We studied 466 kidney recipients from the DIVAT cohort alive with a functioning graft and a surveillance biopsy at 1-year post-transplantation. Patients displaying abnormal histology (49%) (borderline, acute rejection, interstitial fibrosis and tubular atrophy [IFTA] grade 2 or 3, glomerulonephritis) were compared to the normal or subnormal (IFTA grade 1) histology group. Obtained from a lasso penalized logistic regression, the 1-RBI was composed of recipient gender, serum creatinine at 3, 6, and 12 month post-transplantation and anticlass II immunization at transplantation (internal validation: AUC = 0.71, 95% CI [0.53-0.83]; external validation: AUC = 0.62, 95% CI [0.58-0.66]). While we could not determinate a threshold able to identify patients at high chance of normal or subnormal histology, we estimated and validated a discriminating threshold capable of identifying a subgroup of 15% of the patients with a risk of abnormal histology higher than 80%. The 1-RBI is computable online at www.divat.fr. The 1-RBI could be a useful tool to standardize 1-year biopsy proposal and may for instance help to indicate one in case of high risk of abnormal histology.

Clinical Presentation, Pathological Spectrum, and Outcomes of Alcoholic Cirrhosis-Related Immunoglobulin A Nephropathy.

Introduction: Immunoglobulin A nephropathy (IgAN) associated with cirrhosis is frequent but often overlooked because it is largely considered silent. Until now, little has been known about their presentation and outcomes. Methods: We conducted a retrospective multicenter study on patients with kidney biopsy-proven cirrhosis-related IgAN (cirrhosis-IgAN), diagnosed between 2009 and 2022. We mixed them up with 83 primary IgAN (pIgAN) diagnosed during the same period, using a partitioning clustering approach, to determine common clinicopathological profiles. Results: All the 46 patients with cirrhosis-IgAN had an excessive alcoholic consumption. Clinical presentation was severe with acute kidney injury (AKI) in 79%; alternative causes of AKI was found in 62% of cases. Three clinicopathological clusters were identified as follows: the first one represented chronic involvement, the second one could be assimilated to mild disease, and the third one corresponded to a membranoproliferative glomerulonephritis (MPGN) pattern and was associated with heavy proteinuria and intrinsic AKI (without alternative causes). Whereas the first 2 clusters were equally distributed between pIgAN and cirrhosis-IgAN, the third was more frequent in patients with cirrhosis. The cumulative mortality rate in cirrhosis-IgAN was 26% and 46% at 1-year and 3-years, respectively. Steroid exposure and moderate or severe AKI were associated with higher mortality and steroid exposure was associated with the occurrence of severe infection. Conclusion: Our results suggest that high AKI incidence is related to extrinsic causes in most cases but can also be driven by IgA-dominant MPGN in a subset of patients. Steroid use was associated with infectious disease and mortality. Further studies are needed to clarify the role of immunosuppressive treatment in cirrhosis-IgAN patients.

Incidence, Risk Factors and Outcomes of Kidney and Liver Cyst Infection in Kidney Transplant Recipient With ADPKD.

Introduction: Cyst infection is a known complication of autosomal dominant polycystic kidney disease (ADPKD). Here, we describe incidence, risk factors, clinical presentation, and outcomes of cyst infection in kidney transplant recipient. Methods: We conducted a single-center retrospective cohort study of patients with ADPKD with renal allografts between January 1, 2009, and October 31, 2020. Cyst infection diagnosis was based on previously described clinical and radiological criteria, using positron emission tomography when available. Results: A total of 296 patients with ADPKD with renal allografts were included, and 21 patients experienced 22 episodes of cyst infection over a median follow-up of 4 (2-7) years. The cumulative incidence rate was 3% at 1 year, 6 % at 5 years, and 12% at 10 years after transplantation. In multivariate analysis, history of cyst infection before transplantation was the only significant risk factor identified to predict the occurrence of cyst infection after kidney transplantation (hazard ratio [HR] 3.47, 95% CI 1.29-9.31). The clinical presentation at diagnosis of cyst infection included isolated fever in 5 (23%) episodes, acute kidney injury in 12 (55%), and severe sepsis/septic shock in 3 (14%) episodes. Among the 16 (73%) episodes with culture positivity, Escherichia coli was the most common pathogen. There was no difference between early (≤1 year after transplantation) and late (>1 year) cyst infection episodes in terms of clinical presentation and outcomes. Cyst infection was significantly associated with graft loss (HR 3.93, 95% CI 1.21-12.80), but no causal relationship could be established. Conclusion: Incidence of cyst infection in ADPKD after kidney transplantation is low, history of cyst infection representing the main risk factor.

Disease Activity and Adverse Events in Patients with ANCA-Associated Vasculitides Undergoing Long-Term Dialysis.

BACKGROUND AND OBJECTIVES: Kidney impairment of ANCA-associated vasculitides can lead to kidney failure. Patients with kidney failure may suffer from vasculitis relapses but are also at high risk of infections and cardiovascular events, which questions the maintenance of immunosuppressive therapy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients with ANCA-associated vasculitides initiating long-term dialysis between 2008 and 2012 in France registered in the national Renal Epidemiology and Information Network registry and paired with the National Health System database were included. We analyzed the proportion of patients in remission off immunosuppression over time and overall and event-free survival on dialysis (considering transplantation as a competing risk). We compared the incidence of vasculitis relapses, serious infections, cardiovascular events, and cancers before and after dialysis initiation. RESULTS: In total, 229 patients were included: 142 with granulomatous polyangiitis and 87 with microscopic polyangiitis. Mean follow-up after dialysis initiation was 4.6±2.7 years; 82 patients received a kidney transplant. The proportion of patients in remission off immunosuppression increased from 23% at dialysis initiation to 62% after 5 years. Overall survival rates on dialysis were 86%, 69%, and 62% at 1, 3, and 5 years, respectively. Main causes of death were infections (35%) and cardiovascular events (26%) but not vasculitis flares (6%). The incidence of vasculitis relapses decreased from 57 to seven episodes per 100 person-years before and after dialysis initiation (P=0.05). Overall, during follow-up, 45% of patients experienced a serious infection and 45% had a cardiovascular event, whereas 13% experienced a vasculitis relapse. CONCLUSIONS: The proportion of patients with ANCA-associated vasculitis in remission off immunosuppression increases with time spent on dialysis. In this cohort, patients were far less likely to relapse from their vasculitis than to display serious infectious or cardiovascular events. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_11_08_CJN03190321.mp3.

Differential modulation of donor-specific antibodies after B-cell depleting therapies to cure chronic antibody mediated rejection.

BACKGROUND: Donor-specific antibodies (DSA) are considered as reliable biomarkers for antibody-mediated rejection (ABMR) diagnosis. However, it is unclear whether DSA monitoring is necessary and could predict graft outcome after antirejection treatment. METHODS: We analyzed 28 non-sensitized kidney transplant patients with ABMR associated with de novo anti-human leukocyte antigen (HLA) DSA. Donor-specific antibody levels were measured by single antigen bead assays 12 months after antirejection therapy onset. Patients were placed in three groups according to their antirejection treatment: group I (n = 10), plasma exchange-Rituximab; group II (n = 8), Bortezomib; and group III (n = 10), optimization of maintenance immunosuppression. Half of the patients in group I demonstrated concomitant acute cellular rejection (ACR+). RESULTS: De novo DSA were mainly anti-DQ (60%). Anti-class I and anti-DR DSA disappeared after treatment in group I and remained negative during follow-up, whereas anti-DQ DSA persisted without any modulation. In contrast, class I-II HLA-DSA mean fluorescence intensity remained unchanged in groups II and III.Graft loss was observed in 80% and 20% of patients from group I (ACR+) and group III, respectively. One year after the ABMR treatment, a 16-mL/min decline in estimated glomerular filtration rate was observed in patients from group I (ACR-) and group III. Group II showed better outcomes with a mean estimated glomerular filtration rate decline of 6.4 mL/min. CONCLUSION: Modulation of DSA at and after treatment of ABMR did not correlate with graft outcome over a 12-month period.

Rabbit antithymocyte globulin-induced serum sickness disease and human kidney graft survival.

BACKGROUND: Rabbit-generated antithymocyte globulins (ATGs), which target human T cells, are widely used as immunosuppressive agents during treatment of kidney allograft recipients. However, ATGs can induce immune complex diseases, including serum sickness disease (SSD). Rabbit and human IgGs have various antigenic differences, including expression of the sialic acid Neu5Gc and α-1-3-Gal (Gal), which are not synthesized by human beings. Moreover, anti-Neu5Gc antibodies have been shown to preexist and be elicited by immunization in human subjects. This study aimed to assess the effect of SSD on long-term kidney allograft outcome and to compare the immunization status of grafted patients presenting with SSD following ATG induction treatment. METHODS: We analyzed data from a cohort of 889 first kidney graft recipients with ATG induction (86 with SSD [SSD(+)] and 803 without SSD [SSD(-)]) from the Données Informatisées et Validées en Transplantation data bank. Two subgroups of SSD(+) and SSD(-) patients that had received ATG induction treatment were then assessed for total anti-ATG, anti-Neu5Gc, and anti-Gal antibodies using ELISA assays on sera before and after transplantation. RESULTS: SSD was significantly associated with long-term graft loss (>10 years, P = 0.02). Moreover, SSD(+) patients exhibited significantly elevated titers of anti-ATG (P = 0.043) and anti-Neu5Gc (P = 0.007) IgGs in late post-graft samples compared with SSD(-) recipients. CONCLUSION: In conclusion, our data indicate that SSD is a major contributing factor of late graft loss following ATG induction and that anti-Neu5Gc antibodies increase over time in SSD(+) patients. FUNDING: This study was funded by Société d'Accélération du Transfert de Technologies Ouest Valorisation, the European FP7 "Translink" research program, the French National Agency of Research, Labex Transplantex, the Natural Science and Engineering Research Council of Canada, and the Canadian Foundation for Innovation.

[Prospective study of drug-induced interstitial nephritis in eleven French nephrology units]. / Médicaments à l'origine d'insuffisances rénales aiguës allergiques en France en 2013.

OBJECTIVE: Certain medications have been associated with drug-induced acute interstitial nephritis (AIN), but few prospective studies have been published. This prospective observational study aims to record and assess incidents of drug-induced AIN observed over a period of one year in nephrology units in France. The goal is to determine which medications are involved in AIN and to expound the clinical and biological presentation, management, and evolution of AIN. METHODS: Between April 2012 and April 2013, drug-associated cases of AIN were prospectively recorded in 24 patients registered in 11 nephrology units that belong to the Société de Néphrologie de l'Ouest (SNO). Data sheets, including suspected and concomitant drug(s), kidney function assessment, biological disturbances, clinical signs, histological data, management, and evolution, were collected by the Rennes Regional Pharmacovigilance Center and recorded in the French pharmacovigilance database. RESULTS: In order, the most frequently involved medications in the AIN cases were: vitamin K antagonists (33.3% of the cases, almost exclusively fluindione), antibiotics (20.8% of cases) non-steroidal anti-inflammatory drugs (20.8% of cases), and proton pump inhibitors (16.7% of cases). The mean delay of onset to AIN was 8.3 weeks. At the time of diagnosis, mean serum creatinine was 366 µM, higher for vitamin K antagonists (VKAs), except in the case of warfarin. During the course of an AIN event, 70% of patients had complete blood count and/or urine analysis abnormalities, 55% had clinical signs of systemic hypersensitivity, and 13% of patients had hepatic disorders. Renal biopsies were performed in 54% of patients; however, only 37% of patients requiring therapeutic anticoagulation underwent a biopsy. Suspected drugs were discontinued in all patients and the majority was treated with oral corticosteroids. Renal function often continued to be impaired after an AIN event. At baseline, 25% of patients had chronic kidney disease (CKD); after an AIN event, 67% of patients were noted to have CKD. CONCLUSION: Physicians need to be aware of the possibility of drug-induced acute interstitial nephritis as a common cause of acute kidney injury (AKI). This study supports increased vigilance when prescribing three therapeutic classes frequently associated with AIN: antibiotics, NSAIDs and PPIs (especially in instances of polypharmacy), which were associated with two thirds of the AIN cases in this study. Fluindione, an oral anticoagulant exclusively marketed in Luxembourg and France where it constitutes the vast majority of VKA prescriptions, was associated with one third of the AIN cases alone, making it a common possible culprit of drug-induced AIN, warranting particular attention.

The spectrum of renal involvement in patients with inflammatory myopathies.

Data regarding the incidence and outcome of renal involvement in patients with inflammatory myopathies (IM) remain scarce. We assessed the incidence and causes of acute kidney injury (AKI) and chronic kidney disease (CKD) in 150 patients with dermatomyositis, polymyositis, and antisynthetase syndrome followed in 3 French referral centers. Renal involvement occurred in 35 (23.3%) patients: AKI in 16 (10.7%), and CKD in 31 (20.7%) patients. The main cause of AKI was drug or myoglobinuria-induced acute tubular necrosis. Male sex, cardiovascular risk factors, cardiac involvement, and initial proteinuria >0.3 g/d were associated with the occurrence of AKI. The outcome of patients with AKI was poor: 13 (81%) progressed to CKD and 2 (12.5%) reached end-stage renal disease. In multivariate survival analysis, age at IM onset, male sex, a history of cardiovascular events, and a previous episode of AKI were associated with the risk of CKD. We also identified 14 IM patients who underwent a kidney biopsy in 10 nephrology centers. Renal pathology disclosed a wide range of renal disorders, mainly immune-complex glomerulonephritis. We identified in 5 patients a peculiar pattern of severe acute renal vascular damage consisting mainly of edematous thickening of the intima of arterioles. We found that AKI and CKD are frequent in patients with IM. Prevention of AKI is crucial in these patients, as AKI is a major contributor to their relatively high risk of CKD. A peculiar pattern of acute vascular damage is part of the spectrum of renal diseases associated with IM.