Key Points Nilotinib demonstrated efficacy and a manageable safety profile in pediatric patients with newly diagnosed and pretreated Ph+ CML-CP.

Mobilization of suitable amounts of PBSCs with granulocyte-CSF (G-CSF) can be difficult in children. We report the results of using plerixafor in pediatric patients who failed to mobilize progenitors with G-CSF-based regimens. Thirty-three patients, median age 9 years (range 1-18 years) and median weight 29 kg (range 10-85 kg) were enrolled into the study. After 4 days of G-CSF stimulation, the median CD34+ cell count in peripheral blood was 10.4 per μL (range 0.27-23.0 per μL). Plerixafor was administered subcutaneously (0.24 μg/kg in 30 patients and 0.3 μg/kg in 3 patients) 11-12 h before apheresis. At the time of apheresis, CD34+ cell counts increased to a median of 44.1 per μL (range 8.4-357.0 per μL), a median 4.4-fold increase. Two patients (6%) failed to mobilize. Thirty-one patients underwent apheresis and in 27 42 × 10 6 CD34+ cells per kg of body weight were collected after one procedure. In total, 31 of 33 patients mobilized successfully and the median number of cryopreserved CD34+ cells was 5.6 × 10 6 /kg body weight (2.7 × 10 6 -27.4 × 10 6 ). Twenty-four patients underwent transplantation. Engraftment was achieved in all but one patient, who died on day +9 after hematopoietic stem cell transplantation. The median time of neutrophil and platelet recovery was day +12 and +16, respectively. Our study confirms that plerixafor has impressive efficacy and very modest toxicity in children.

BackgroundNijmegen breakage syndrome (NBS) is a combined primary immunodeficiency with DNA repair defect, microcephaly, and other phenotypical features. It predominantly occurs in Slavic populations that have a high frequency of carriers with the causative NBN gene c.657_661del5 mutation. Due to the rarity of the disease in the rest of the world, studies of NBS patients are few. Here, we report a prospective study of a cohort of Russian NBS patients.Methods35 Russian NBS patients of ages 1–19 years, referred to our Center between years 2012 and 2016, were prospectively studied.ResultsDespite the fact that in 80% of the patients microcephaly was diagnosed at birth or shortly thereafter, the average delay of NBS diagnosis was 6.5 years. Though 80% of the patients had laboratory signs of immunodeficiency, only 51% of the patients experienced significant infections. Autoimmune complications including interstitial lymphocytic lung disease and skin granulomas were noted in 34%, malignancies—in 57% of the patients. T-cell excision circle (TREC)/kappa-deleting recombination excision circle (KREC) levels were low in the majority of patients studied. Lower KREC levels correlated with autoimmune and oncological complications. Fifteen patients underwent hematopoietic stem cell transplantation (HSCT), 10 of them were alive and well, with good graft function. Three patients in the HSCT group and five non-transplanted patients died; tumor progression being the main cause of death. The probability of the overall survival since NBS diagnosis was 0.76 in the HSCT group and 0.3 in the non-transplanted group.ConclusionBased on our findings of low TRECs in most NBS patients, independent of their age, TREC detection can be potentially useful for detection of NBS patients during neonatal screening. KREC concentration can be used as a prognostic marker of disease severity. HSCT is a viable treatment option in NBS and should be especially considered in patients with low KREC numbers early on, before development of life-threatening complications.

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In the mid-1990s, we introduced a fludarabine (Flu)-based conditioning regimen for hematopoietic stem cell transplantation (HSCT) in patients with Fanconi anemia (FA).The aim of this study is to compare Flu-based conditioning to alternative regimens in patients with FA. Forty-one patients with FA (aged 0.5-31, median, 10.3 years) who underwent allogeneic HSCT were included in this retrospective study. Hospital records were reviewed for conditioning regimens, engraftment data, and toxicity. The median (range) follow-up was 32 (0.5-149) months. Flu-based conditioning regimens were used in 24 patients: 17 patients were treated with alternative conditioning regimens including a radiation-based regimen/cyclophosphamide and busulfan regimen. The disease-free survival (DFS) after Flu-based regimens is 83% (20/24) versus 35% (6/17) for the alternative regimens (P = .002). Toxicity was significantly lower in patients who received Flu-based conditioning (modified Bearman toxicity score [P = .001]). Seven patients received transplants from matched unrelated donors without irradiation (5 of whom are currently alive and well). All patients who survived are disease free and in good clinical condition. We conclude that a combination of fludarabine with antithymocyte globulin (ATG) and low-dose cyclophosphamide (Cy) and/or busulfan (Bu) is safe, demonstrates low rejection rates, and is well tolerated by FA patients.