Low-Dose Antithymocyte Globulin Has No Disadvantages to Standard Higher Dose in Pediatric Kidney Transplant Recipients: Report from the Pediatric Nephrology Research Consortium

Introduction Rabbit antithymocyte globulin (rATG) dosing strategies for induction in pediatric kidney transplantation vary between centers. It is not known whether a lower rATG induction dose provides safe and effective immunosuppression compared with a “standard” higher dose. Methods We performed a retrospective multicenter study of all isolated first-time kidney transplant recipients \u3c 21 years old who received rATG induction between 1 January 2010 and 31 December 2014 at 9 pediatric centers. An a priori cutoff of a 4.5-mg/kg cumulative rATG dose was used to identify low (≤ 4.5 mg/kg) and standard (\u3e 4.5 mg/kg) exposure groups. Outcomes examined included 12 months posttransplant graft function (estimated glomerular filtration rate [eGFR]); the occurrence of acute rejection, donor-specific antibody (DSA), neutropenia, and viral infection (cytomegalovirus [CMV], Epstein-Barr virus [EBV], and BK virus); and 24-month outcomes of posttransplant lymphoproliferative disorder (PTLD) occurrence and patient and graft survival. Results Two hundred thirty-five patients were included. Baseline features of the low and standard rATG dose groups were similar. By 12 months, the rATG dose group had no significant impact on the occurrence of neutropenia, positive DSA, or viral polymerase chain reaction (PCR). Graft function was similar. Acute rejection rates were similar at 17% (low dose) versus 19% (standard dose) (P = 0.13). By 24 months, graft survival (96.4% vs. 94.6%) and patient survival (100% vs. 99.3%) were similar between the low- and standard-dose groups (P = 0.54 and 0.46), whereas the occurrence of PTLD trended higher in the standard-dose group (0% vs. 2.6%, P = 0.07). Conclusion A low rATG induction dose ≤ 4.5 mg/kg provided safe and effective outcomes in this multicenter low immunologic risk pediatric cohort. Prospective studies are warranted to define the optimal rATG induction dose in pediatric kidney transplantation

Soluble urokinase plasminogen activator receptor is associated with kidney disease and its progression in sickle cell anemia

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Practice patterns and influence of allograft nephrectomy in pediatric kidney re- transplantation: A pediatric nephrology research consortium study

IntroductionThere are no guidelines regarding management of failed pediatric renal transplants.Materials & MethodsWe performed a first of its kind multicenter study assessing prevalence of transplant nephrectomy, patient characteristics, and outcomes in pediatric renal transplant recipients with graft failure from January 1, 2006, to December 31, 2016.ResultsFourteen centers contributed data on 186 pediatric recipients with failed transplants. The 76 recipients that underwent transplant nephrectomy were not significantly different from the 110 without nephrectomy in donor or recipient demographics. Fifty- three percent of graft nephrectomies were within a year of transplant. Graft tenderness prompted transplant nephrectomy in 91% (P < .001). Patients that underwent nephrectomy were more likely to have a prior diagnosis of rejection within 3 months (43% vs 29%; P = .04). Nephrectomy of allografts did not affect time to re- listing, donor source at re- transplant but significantly decreased time to (P = .009) and incidence (P = .0002) of complete cessation of immunosuppression post- graft failure. Following transplant nephrectomy, recipients were significantly more likely to have rejection after re- transplant (18% vs 7%; P = .03) and multiple rejections in first year after re- transplant (7% vs 1%; P = .03).ConclusionsPractices pertaining to failed renal allografts are inconsistent- 40% of failed pediatric renal allografts underwent nephrectomy. Graft tenderness frequently prompted transplant nephrectomy. There is no apparent benefit to graft nephrectomy related to sensitization; but timing / frequency of immunosuppression withdrawal is significantly different with slightly increased risk for rejection following re- transplant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/169276/1/petr13974.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/169276/2/petr13974_am.pd

Antibody-Mediated Rejection in Pediatric Kidney Transplant Recipients: A Report From the Pediatric Nephrology Research Consortium

BACKGROUND: Antibody-mediated rejection (AMR) is a major cause of kidney allograft loss. There is a paucity of large-scale pediatric-specific data regarding AMR treatment outcomes. METHODS: Data were obtained from 14 centers within the Pediatric Nephrology Research Consortium. Kidney transplant recipients aged 1-18 years at transplant with biopsy-proven AMR between 2009 and 2019 and at least 12 months of follow-up were included. The primary outcome was graft failure or an eGFR \u3c20 mL/min/1.73 m at 12 months following AMR treatment. AMR treatment choice, histopathology, and DSA class were also examined. RESULTS: We reviewed 123 AMR episodes. Median age at diagnosis was 15 years at a median 22 months post-transplant. The primary outcome developed in 27.6%. eGFR \u3c30 m/min/1.73 m at AMR diagnosis was associated with a 5.6-fold higher risk of reaching the composite outcome. There were no significant differences in outcome by treatment modality. Histopathology scores and DSA class at time of AMR diagnosis were not significantly associated with the primary outcome. CONCLUSIONS: In this large cohort of pediatric kidney transplant recipients with AMR, nearly one-third of patients experienced graft failure or significant graft dysfunction within 12 months of diagnosis. Poor graft function at time of diagnosis was associated with higher odds of graft failure

Kidney biopsy findings in children with sickle cell disease: a Midwest Pediatric Nephrology Consortium study

Renal damage is a progressive complication of sickle cell disease (SCD). Microalbuminuria is common in children with SCD, while a smaller number of children have more severe renal manifestations necessitating kidney biopsy. There is limited information on renal biopsy findings in children with SCD and subsequent management and outcome. This is a multicenter retrospective analysis of renal biopsy findings and clinical outcomes in children and adolescents with SCD. We included children and adolescents (age ≤ 20 years) with SCD who had a kidney biopsy performed at a pediatric nephrology unit. The clinical indication for biopsy, biopsy findings, subsequent treatments, and outcomes were analyzed. Thirty-six SCD patients (ages 4-19 years) were identified from 14 centers with a median follow-up of 2.6 years (0.4-10.4 years). The indications for biopsy were proteinuria (92%) and elevated creatinine (30%). All biopsies had abnormal findings, including mesangial hypercellularity (75%), focal segmental glomerulosclerosis (30%), membranoproliferative glomerulonephritis (16%), and thrombotic microangiopathy (2%). There was increased use of hydroxyurea, angiotensin-converting-enzyme inhibitors, and angiotensin receptor blockers following renal biopsy. At last follow-up, 3 patients were deceased, 2 developed insulin-dependent diabetes mellitus, 6 initiated chronic hemodialysis, 1 received a bone marrow transplant, and 1 received a kidney transplant. Renal biopsies, while not commonly performed in children with SCD, were universally abnormal. Outcomes were poor in this cohort of patients despite a variety of post-biopsy interventions. Effective early intervention to prevent chronic kidney disease (CKD) is needed to reduce morbidity and mortality in children with SCD

Eculizumab Exposure in Children and Young Adults: Indications, Practice Patterns, and Outcomes—A Pediatric Nephrology Research Consortium Study

Background: Eculizumab is approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Its use off-label is frequently reported. The aim of this study was to describe the broader use and outcomes of a cohort of pediatric patients exposed to eculizumab. Methods: A retrospective, cohort analysis was performed on the clinical and biomarker characteristics of eculizumab-exposed patients \u3c 25 years of age seen across 21 centers of the Pediatric Nephrology Research Consortium. Patients were included if they received at least one dose of eculizumab between 2008 and 2015. Traditional summary statistics were applied to demographic and clinical data. Results: A total of 152 patients were identified, mean age 9.1 (+/−6.8) years. Eculizumab was used off-label in 44% of cases. The most common diagnoses were aHUS (47.4%), Shiga toxin-producing Escherichia coli HUS (12%), unspecified thrombotic microangiopathies (9%), and glomerulonephritis (9%). Genetic testing was available for 60% of patients; 20% had gene variants. Dosing regimens were variable. Kidney outcomes tended to vary according to diagnosis. Infectious adverse events were the most common adverse event (33.5%). No cases of meningitis were reported. Nine patients died of noninfectious causes while on therapy. Conclusions: This multi-center retrospective cohort analysis indicates that a significant number of children and young adults are being exposed to C5 blockade for off-label indications. Dosing schedules were highly variable, limiting outcome conclusions. Attributable adverse events appeared to be low. Cohort mortality (6.6%) was not insignificant. Prospective studies in homogenous disease cohorts are needed to support the role of C5 blockade in kidney outcomes

Eculizumab Exposure in Children and Young Adults: Indications, Practice Patterns, and Outcomes—A Pediatric Nephrology Research Consortium Study

Background: Eculizumab is approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Its use off-label is frequently reported. The aim of this study was to describe the broader use and outcomes of a cohort of pediatric patients exposed to eculizumab. Methods: A retrospective, cohort analysis was performed on the clinical and biomarker characteristics of eculizumab-exposed patients \u3c 25 years of age seen across 21 centers of the Pediatric Nephrology Research Consortium. Patients were included if they received at least one dose of eculizumab between 2008 and 2015. Traditional summary statistics were applied to demographic and clinical data. Results: A total of 152 patients were identified, mean age 9.1 (+/−6.8) years. Eculizumab was used off-label in 44% of cases. The most common diagnoses were aHUS (47.4%), Shiga toxin-producing Escherichia coli HUS (12%), unspecified thrombotic microangiopathies (9%), and glomerulonephritis (9%). Genetic testing was available for 60% of patients; 20% had gene variants. Dosing regimens were variable. Kidney outcomes tended to vary according to diagnosis. Infectious adverse events were the most common adverse event (33.5%). No cases of meningitis were reported. Nine patients died of noninfectious causes while on therapy. Conclusions: This multi-center retrospective cohort analysis indicates that a significant number of children and young adults are being exposed to C5 blockade for off-label indications. Dosing schedules were highly variable, limiting outcome conclusions. Attributable adverse events appeared to be low. Cohort mortality (6.6%) was not insignificant. Prospective studies in homogenous disease cohorts are needed to support the role of C5 blockade in kidney outcomes

An automated histological classification system for precision diagnostics of kidney allografts

International audienceFor three decades, the international Banff classification has been the gold standard for kidney allograft rejection diagnosis, but this system has become complex over time with the integration of multimodal data and rules, leading to misclassifications that can have deleterious therapeutic consequences for patients. To improve diagnosis, we developed a decision-support system, based on an algorithm covering all classification rules and diagnostic scenarios, that automatically assigns kidney allograft diagnoses. We then tested its ability to reclassify rejection diagnoses for adult and pediatric kidney transplant recipients in three international multicentric cohorts and two large prospective clinical trials, including 4,409 biopsies from 3,054 patients (62.05% male and 37.95% female) followed in 20 transplant referral centers in Europe and North America. In the adult kidney transplant population, the Banff Automation System reclassified 83 out of 279 (29.75%) antibody-mediated rejection cases and 57 out of 105 (54.29%) T cell-mediated rejection cases, whereas 237 out of 3,239 (7.32%) biopsies diagnosed as non-rejection by pathologists were reclassified as rejection. In the pediatric population, the reclassification rates were 8 out of 26 (30.77%) for antibody-mediated rejection and 12 out of 39 (30.77%) for T cell-mediated rejection. Finally, we found that reclassification of the initial diagnoses by the Banff Automation System was associated with an improved risk stratification of long-term allograft outcomes. This study demonstrates the potential of an automated histological classification to improve transplant patient care by correcting diagnostic errors and standardizing allograft rejection diagnose