Adverse reactions (ARs) during the infusion of cellular therapy products (CTPs) are common in patients undergoing hematopoietic stem cell transplantation (HSCT). We retrospectively studied pediatric patients undergoing autologous and allogeneic HSCT to determine the incidence and grade of ARs during stem cell infusion and their predictors. We analyzed data from 213 patients (120 allogeneic and 93 autologous) who received at least 1 CTP, totaling 361 infusion episodes. Serious ARs, defined as grade 2 and 3, occurred in 25 and 11% of infusions, respectively. No grade 4 or 5 ARs were noted. Independent risk factors for developing a serious AR included stem cell source (PBSC vs marrow (odds ratio (OR) 1.8, 95% confidence interval (CI): 0.4-9); cord vs marrow (OR 7.3, 95% CI: 1.3-40), overall P = 0.0001) but manipulated CTPs were protective (OR 0.4, 95% CI: 0.2-0.7, P = 0.004). Unlike previous adult studies, WBC and granulocyte content were not found to be risk factors in this pediatric population. These data suggest that children tolerate higher WBC content during infusion of CTPs and support the use of manipulated CTP, as indicated, to reduce the risk of adverse infusion reactions.

Juvenile myelomonocytic leukaemia (JMML) is a rare, aggressive myeloproliferative neoplasm that responds poorly to conventional chemotherapy. [1][2][3] With the exception of rare cases of spontaneous remission seen in children with specific molecular mutations, allogeneic haematopoietic SCT (HSCT) is the only curative therapy. Myeloablative conditioning is widely considered to be essential to eradicate leukaemic clones and to faciliate engraftment. Owing to historically high rates of treatment-related mortality (TRM) in children with JMML, efforts are ongoing to develop newer approaches to HSCT therapy to reduce toxicities, including reduced-toxicity myeloablative conditioning regimens. We present pilot data on three children who underwent HSCT with such an approach.A search of our institutional database was performed, and three patients were identified with a diagnosis of JMML who received a reduced-toxicity regimen. A retrospective chart review of the clinical records of the three cases was subsequently conducted to gather data. The database and clinical records were housed at Alberta Children's Hospital in Calgary, Alberta, Canada. This retrospective study was approved by the University of Calgary Conjoint Health Research Ethics Board.All patients received the same regimen consisting of i.v. BU (4 mg/kg/day once daily, days − 5 to − 2), i.v. fludarabine (50 mg/ m 2 /day, days − 6 to − 2), i.v. rabbit ATG (0.5 mg/kg on day − 3 and 2.5 mg/kg/day on days − 2 and − 1) and 400 cGy of TBI on day − 1. BU pharmacokinetics were calculated based on an institutional practise of test dosing before the administration of full dosing, usually day − 7. The target area under the curve (AUC) was 3800 μM Á min. GVHD prophylaxis consisted of CYA in combination with MTX for live donor stem cell products or methylprednisolone for umbilical cord blood (UCB) infusions. Filgrastim was given post HSCT with UCB products. Institutional antimicrobial prophylaxis included acyclovir, fluconazole and metronidazole. Seizure prophylaxis with lorazepam was given one day before BU exposure and continued until 1 day after completion.All three cases met modified JMML diagnostic criteria.