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Background: Alterations of 11q23/KMT2A are the most prevalent cytogenetic abnormalities in acute myeloid leukemia (AML) and the prognostic significance of 11q23/KMT2A‐rearranged AML based on various translocation partners varies among different studies. However, few studies evaluated the molecular characteristics of 11q23/KMT2A‐rearranged pediatric AML. We aim to analyze the mutational landscape of 11q23/KMT2A‐rearranged AML and assess their prognostic value in outcomes. Methods: The mutational landscape and clinical prognosis of 105 children with 11q23/KMT2A‐rearranged AML in comparison with 277 children with non‐11q23/KMT2A‐rearranged AML were analyzed using publicly accessible next‐generation sequencing data from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset. Results: Pediatric AML patients with 11q23/KMT2A‐rearrangements harbored a low number of mutations (Median, 1 mutation/patient, range, 1‐22), 58% of which involved in RAS pathway mutations (KRAS, NRAS, and PTPN11) and 10.5% of which comprised of SETD2 mutations. Compared with non‐11q23/KMT2A‐rearranged AML, the incidence of KRAS (32.4% vs. 10.1%, P〈0.001) and SETD2 (10.5% vs. 1.4%, P=0.001) gene mutations in 11q23/KMT2A‐rearranged AML was significantly higher. Both KRAS and SETD2 mutations occurred more often in t(10;11)(p12;q23). KRAS mutations were correlated with worse 5‐year event‐free survival [EFS] (Plog‐rank = 0.001) and 5‐year overall survival [OS] (Plog‐rank = 0.009) and the presence of SETD2 mutations increases the 5‐year relapse rate (PGray = 0.004). Multivariate analyses confirmed KRAS mutations in 11q23/KMT2A‐rearranged AML as an independent predictor for poor EFS (hazard ratio [HR] = 2.10, P=0.05) and OS (HR = 2.39, P=0.054). Conclusion: Our findings show that pediatric patients with 11q23/KMT2A rearrangements have characteristic mutation patterns and varying clinical outcomes depending on different translocation partners, which could be utilized to develop more accurate risk stratification and tailored therapies. [ABSTRACT FROM AUTHOR]

Our aim is to evaluate initial efficacy, safety, and durable response of eltrombopag in the treatment of Chinese children with chronic immune thrombocytopenia (cITP). This was a retrospective, single-center cohort study including 30 pediatric patients with cITP administered eltrombopag between 1 July 2017 and 1 January 2019. Patients with at least 12 weeks of eltrombopag treatment and available follow-up data were included. Initial response rate, durable response rate, bleeding events, and adverse events were assessed during the follow-up period. The median duration of eltrombopag administration was 6 months (range 3–8 months). The initial response rate was 73.3%. Patients with megakaryocyte count ≥100/slide or Treg <4.5% were more likely to achieve initial response. The median follow-up period was 10 months (range 6–20 months). A total of 53.2% of pediatric patients had a durable response of up to 20 months. Patients with megakaryocyte count ≥100/slide and Treg<4.5% had more than 60% durable response rates compared with individuals with megakaryocyte count<100/slide and Treg≥4.5%, respectively. No serious bleeding events or serious adverse events occurred during the study period. Eltrombopag not only shows excellent initial response but also has continued efficacy and safety. Patients with megakaryocyte count ≥100/slide and Treg<4.5% achieve increased initial response and more frequent durable response. [ABSTRACT FROM AUTHOR]

Aims: The purpose of this study is to examine the safety and efficacy of eltrombopag as first‐line treatment for thrombocytopenia among paediatric patients after haematopoietic stem cell transplantation (HSCT). Methods: Forty‐three childhood patients with thrombocytopenia after HSCT who received eltrombopag were retrospectively analysed. Result: Eltrombopag was began at the median of 27 days after HSCT and lasted for 24 days. Thirty‐five children responded to eltrombopag therapy, and the cumulative platelet recovery rate was 88.9%. The cumulative incidence of platelet recovery was lower (83.9 vs 100%; P =.035) in patients with decreased numbers of megakaryocytes before starting eltrombopag than in those with normal. Factors associated with a significantly elevated response to eltrobopag from univariate analysis were donor type. Results from the multiple regression analysis found that weight (hazard ratio [HR] = 0.7, 95% confidence interval [CI] 0.5–0.9, P =.022), platelet engraftment time (HR = 1.0, 95%CI 1.0–1.0, P =.012) and bone marrow megakaryocytes (HR = 8.0, 95%CI 1.5–43.3, P =.016) before starting eltrombopag were the independent risk factors. Based on Youden's index algorithm in the receiver‐operating characteristic curve, the optimal cut‐off value of the maintenance dose of eltrombopag in predicting nonresponders was 4 mg/kg. The area under the receiver‐operating characteristic curve was 0.923 with sensitivity of 97.8%, specificity of 87.9%, positive predictive value of 72.3%, and negative predictive value of 92%. None of the paediatric patients stopped using eltrombopag due to side effect or intolerability. Conclusion: Eltrombopag is effective and safe in paediatric patients with thrombocytopenia after HSCT. The number of megakaryocytes in bone marrow before eltrombopag treatment may serve as a predictor of the response to eltrombopag. We recommend that the maintenance dose of eltrombopag should not exceed 4 mg/kg/d. [ABSTRACT FROM AUTHOR]

Thalassemic children are at a high risk of graft rejection in cord blood transplantation. To investigate this possible mechanism, the authors evaluated the effect of panel reactive antibody on the growth of CD34+ cells in vitro. On semisolid medium, CD34+ cells derived from cord blood were incubated with thalassemic serum, and colony-forming units were counted after 10 days of culture. After incubation with serum-specific panel reactive antibody, profound decreases were found in the numbers of CFU-GM, CFU-GEMM and BFU-E compared with controls. The results indicated that serum-specific panel reactive antibody might have an apparent inhibition effect on proliferation and differentiation of cord blood CD34+ cells. [ABSTRACT FROM AUTHOR]

Background: Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognized serious complication of cyclosporine A (CSA) and tacrolimus (TAC) use in hematopoietic cell transplantation (HCT) recipients. Procedure: A retrospective study was carried out, including 84 cases of HCT for TM from January 2012 to January 2017. Eleven cases were diagnosed with PRES. Results: The cumulative incidence of PRES was 13.4% (95% confidence interval (CI) 9.7%‐17.2%). The median onset time of the symptoms was 63 [20, 143] days after transplantation. Lumber puncture found that CSF was normal. Univariate analysis showed that patients who received methylprednisolone (MP) (OR = 10.629 95% CI, 1.360‐83.071, P = 0.024), female patients (OR = 4.275, 95% CI, 1.154‐15.843, P = 0.032), patients who had severe hypertension (OR = 5.162, 95% CI, 1.042 to 25.559, P = 0.029) had significantly higher risks of PRES. Multivariate analysis showed that severe hypertension (hazard ratio [HR], 12.793; 95% CI, 1.477 to 110.813; P  = 0.021), and Pesaro class 3 (HR, 3.367; 95% CI, 1.210 to 9.368; P  =  0.020) were associated with PRES. Conclusions: The severe hypertension is an independent risk factor for PRES post‐HCT in children with thalassemia major. Patients of Pesaro class 3 may benefit from optimum control of blood pressure post‐HCT for prophylaxis of PRES. [ABSTRACT FROM AUTHOR]

Objective: To investigate the changes of hepcidin and ferropotin 1 expression in murine model of iron overload., Methods: The murine model of iron overload was established, C57BL/6 mice were injected with iron dextran intraperitoneally (10 mg) every 3 days for 4 weeks. Blood routine, serum ferritin and pathological sections were tested at the appointed time-point respectively (before iron injection, 2 weeks and 4 weeks after treatment of iron injection). The serum hepcidin was assayed by enzyme-linked immunosorbent method. The expression of ferroportin 1 in bone marrow cells was detected by RT-PCR and Western blot, respectively. The labile iron pool of bone marrow cells was measured by flow cytometry., Results: The absolute number and percentage of reticulocytes in the iron-overloaded mice were significantly decreased along with the increase of iron injection times (r=-0.938, r=-0.947), while no significant change was found in the number of white blood cells, hemoglobin level and platelet count. The level of serum ferritin was increased along with increase of iron injection time (r=0.894). Iron overload was found in pathological sections of different organs. Furthermore, serum hepcidin was increased along with increase of iron injection time (r=0.957). RT-PCR and Western blot analyses showed that the expressions of ferroportin 1 at mRNA and protein level were increased in the murine model of iron overload (P<0.05). Labile iron pool in bone marrow cells was also found to be increased in the murine model of iron overload(P<0.05)., Conclusion: The expressions of hepcidin and ferroportin 1 are increase in a murine model of iron overload, which may be contributed to the suppression effect on erythropoiesis in bone marrow.