Background Busulfan (Bu) is a key component of several conditioning regimens used before hematopoietic stem cell transplantation (HSCT). However,the optimum systemic exposure (expressed as the area under the concentration-time curve [AUC]) of Bu for clinical outcome in children is controversial. Methods Research on pertinent literature was carried out at PubMed, EMBASE, ClinicalTrials.gov and the Cochrane Library. Observational studies were included, which compared clinical outcomes above and below the area under the concentration-time curve (AUC) cut-off value, which we set as 800, 900, 1000, 1125, 1350, and 1500 µM × min. The primary efficacy outcome was notable in the rate of graft failure. In the safety outcomes, incidents of veno-occlusive disease (VOD) were recorded, as well as other adverse events. Results Thirteen studies involving 548 pediatric patients (aged 0.3-18 years) were included. Pooled results showed that, compared with the mean Bu AUC (i.e., the average value of AUC measured multiple times for each patient) of > 900 µM × min, the mean AUC value of <900 µM × min significantly increased the incidence of graft failure (RR=3.049, 95% CI: 1.285-7.234). The incidence of VOD was significantly decreased with the mean AUC <1350 µM × min (RR=0.370, 95% CI: 0.205-0.666) and <1500 µM × min(RR=0.409, 95% CI: 0182-0.920). Conclusions In children, Bu the mean AUC of 900 µM × min should be considered the lowest threshold associated with its effective prevention of graft failure, while the mean AUC of >1350 µM × min is associated with increased VOD, particularly for the patients not undergoing VOD prophylaxis therapy.

In this work, a simple and rapid high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed and validated to carry out the simultaneous measurement of busulfan (BU) and phenytoin (PHT) in the plasma of children. In this method, plasma sample could be prepared by one-step protein precipitation using 1 mL of methanol/water (1:1, v/v). After centrifugation (14,500 rpm, 5 min, 4 °C), 10 μL of the supernatant was injected into a Hypersil Gold C18 column (150 × 2.1 mm, 5 μm, Thermo Fisher Scientific) for separation by gradient elution. Quantification was carried out using multiple reactions monitoring (MRM) under positive scan mode. In the method verification, the calibration curves of BU and PHT showed satisfactory linearity (r > 0.99) at the concentration ranging from 0.02 to 20 μg mL−1. The accuracy and precision were tested at four concentration levels (including the LLOQ level) with the relative error (RE) ranging from −0.80% to 11.45% and coefficient of variation (CV) between 0.93% and 7.74%. There was no pronounced matrix effect to interfere with the quantitative analysis. Compared to determine BU and PHT using two individual methods, less pre-treatment process, labor and blood sample volume are required in this proposed method. Finally, this method was successfully applied to the therapeutic drug monitoring of BU and PHT for children underwent hematological stem cell transplantation.

ObjectiveTo evaluate the clinical efficacy of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) for treatment of malignant infantile osteopetrosis (MIOP) and intermediate osteopetrosis.MethodsChildren with MIOP and IOP who underwent haplo-HSCT in Beijing Children’s Hospital, Capital Medical University, from January 2010 to May 2018 were retrospectively analyzed. Data relating to the clinical manifestations, engraftment, and prognosis of the children were extracted from medical records. ResultsTwenty-seven patients, including 18 males and 9 females, with an onset age of 12 (0.04-72) months, were enrolled in this study. The median time from diagnosis to transplantation was 4 (1-23) months. All patients received haplo-HSCT with myeloablative conditioning regimen (including fludarabine, busulfan, and cyclophosphamide). The graft versus host disease (GVHD) prophylaxis was based on anti-human T lymphocyte porcine immunoglobulin /anti-human thymus globulin, methotrexate, and mycophenolate mofetil. The median observation time was 55.2 (0.3-126.2) months. By the end of follow-up, twenty patients survived and seven patients died. The five years overall survival rate was 73.9%. Acute GVHD degree I-II was observed in 20 patients, degree III in 1 patient and without degree IV. Chronic GVHD was observed in 11 patients (40.7%). It was controlled by anti-GVHD therapy.ConclusionHaplo-HSCT was effective for MIOP and IOP, with high survival rate and significantly improved of clinical symptoms. For the patients with vision impairment before HSCT, the improvement was slow after transplantation. The incidence of GVHD was high but mild, and could be effectively controlled after appropriate treatment. These data provided that haplo-HSCT was feasible in the treatment of MIOP and IOP.

Background: Busulfan (Bu) is a key component of several conditioning regimens used before hematopoietic stem cell transplantation (HSCT). However, the optimum systemic exposure (expressed as the area under the concentration-time curve [AUC]) of Bu for clinical outcome in children is controversial.Methods: Research on pertinent literature was carried out at PubMed, EMBASE, ClinicalTrials.gov and the Cochrane Library. Observational studies were included, which compared clinical outcomes above and below the area under the concentration-time curve (AUC) cut-off value, which we set as 800, 900, 1000, 1125, 1350, and 1500 µM × min. The primary efficacy outcome was notable in the rate of graft failure. In the safety outcomes, incidents of veno-occlusive disease (VOD) were recorded, as well as other adverse events.Results: Thirteen studies involving 548 pediatric patients (aged 0.3-18 years) were included. Pooled results showed that, compared with the mean Bu AUC (i.e., the average value of AUC measured multiple times for each patient) of > 900 µM × min, the mean AUC value of <900 µM × min significantly increased the incidence of graft failure (RR=3.666, 95% CI:1. 419, 9.467). The incidence of VOD was significantly decreased with the mean AUC <1350 µM × min (RR=0.370, 95% CI: 0.205-0.666) and <1500 µM × min (RR=0.409, 95% CI: 0182-0.920).Conclusions: In children, Bu mean AUC above the cut-off value of 900 µM × min (after every 6-hour dosing) was associated with decreased rates of graft failure, while the cut-off value of 1350 µM × min were associated with increased risk of VOD in children, particularly for the patients without VOD prophylaxis therapy. Further well-designed prospective and multi centric randomized controlled trials with larger sample size are necessary before putting our result into clinical practices.