Prevalence of mycophenolate mofetil discontinuation and subsequent outcomes in pediatric kidney transplant recipients: A PNRC study.

BACKGROUND: Mycophenolate Mofetil (MMF) is an effective immunosuppressant used in kidney transplant recipients to prevent acute rejection. Complications such as diarrhea, leukopenia, and infections may necessitate the reduction or discontinuation of MMF. The objective of the study was to investigate the prevalence, timing, and reasons for MMF discontinuation and its association with outcomes in pediatric kidney transplant recipients. METHODS: Seven Pediatric Nephrology Research Consortium (PNRC) centers participated in a retrospective analysis of kidney transplant recipients <21 years of age. Characteristics and outcomes of patients in whom MMF was discontinued were compared to those who continued taking MMF throughout the first 2 years post-transplant. RESULTS: The study population included 288 participants (mean age 11.2 years) from 7 North American transplant centers. MMF was discontinued in 93/288 (32%) of participants. Common reasons for discontinuation included infections (35%), diarrhea (32%), leukopenia (15%), and others (18%). Increased cumulative alloimmunity (55% vs. 42%, p = .02), increased number of hospitalizations (82% vs. 67%, p = .01), and viral replications (79% vs. 47%, p < .0001) were observed in the MMF discontinuation group compared to the continuation group. Greater eGFR decline also occurred in the MMF discontinuation group over 2 years of follow-up (-7 vs. -1 mL/min/1.73 m2 , p = .05). CONCLUSIONS: Almost a third of pediatric kidney transplant recipients who begin MMF for maintenance immunosuppression have it discontinued within the first 2 years post-transplant, and this subset of patients is more likely to experience adverse outcomes. New strategies are needed to manage MMF therapy and improve post-transplant outcomes.

Multisite Retrospective Review of Outcomes in Renal Replacement Therapy for Neonates with Inborn Errors of Metabolism.

OBJECTIVE: To assess the outcomes of neonates in a contemporary multi-institutional cohort who receive renal replacement therapy (RRT) for hyperammonemia. STUDY DESIGN: We performed a retrospective analysis of 51 neonatal patients with confirmed inborn errors of metabolism that were treated at 9 different children's hospitals in the US between 2000 and 2015. RESULTS: Twenty-nine patients received hemodialysis (57%), 21 patients received continuous renal replacement therapy (41%), and 1 patient received peritoneal dialysis (2%). The median age at admission of both survivors (n = 33 [65%]) and nonsurvivors (n = 18) was 3 days. Peak ammonia and ammonia at admission were not significantly different between survivors and nonsurvivors. Hemodialysis, having more than 1 indication for RRT in addition to hyperammonemia, and complications during RRT were all risk factors for mortality. After accounting for multiple patient factors by multivariable analyses, hemodialysis was associated with a higher risk of death compared with continuous renal replacement therapy. When clinical factors including evidence of renal dysfunction, number of complications, concurrent extracorporeal membrane oxygenation, vasopressor requirement, and degree of hyperammonemia were held constant in a single Cox regression model, the hazard ratio for death with hemodialysis was 4.07 (95% CI 0.908-18.2, P value = .067). To help providers caring for neonates with hyperammonemia understand their patient's likelihood of survival, we created a predictive model with input variables known at the start of RRT. CONCLUSIONS: Our large, multicenter retrospective review supports the use of continuous renal replacement therapy for neonatal hyperammonemia.

Omentectomy reduces the need for peritoneal dialysis catheter revision in children: a study from the Pediatric Nephrology Research Consortium.

BACKGROUND: There are no multi-center studies examining omentectomy and peritoneal dialysis (PD) catheter revision in the pediatric dialysis population. METHODS: We performed a retrospective study at eight centers within the Pediatric Nephrology Research Consortium (PNRC). Data review included all incident tunneled PD catheters placed between 1/1/2011 and 12/31/2016 in pediatric stage 5 chronic kidney disease (CKD 5) patients. The primary outcome was the need for catheter revision and/or replacement. Multivariable logistic regression was performed to evaluate predictors for catheter revision/replacement. RESULTS: Data from 184 children (62.5% male; median age 7.4 years) were analyzed. Omentectomy was completed in 63.6% (n = 117). Revision/replacement occurred in 34.2% (n = 63); median time to revision/replacement was 38.5 days after insertion. PD catheter revision/replacement catheter occurred in 23.9% who underwent omentectomy versus 52.2% without omentectomy (p = 0.0005). Children ≥ 6 years at the time of catheter insertion experienced fewer revisions/replacements (18.2% age ≥ 6 vs. 56.5% age < 6 years, p <0.001). After adjusting for covariates, omentectomy reduced the need for revision by 63%; revision was 3.66 times more likely in those < 6 years of age. CONCLUSIONS: This multi-center study demonstrates that omentectomy at the time of PD catheter insertion in pediatric patients is strongly associated with reduced likelihood of PD catheter revision. Omentectomy should be considered at the time of PD catheter insertion, especially in young children who are at high risk for PD catheter malfunction. A higher resolution version of the Graphical abstract is available as Supplementary information.

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 < 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.