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Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality post cord blood transplantation (CBT). It has been suggested that the graft-versus-host disease (GVHD) and immunosuppressants have an impact on CMV infection. This study evaluated the incidence, outcomes, and risk factors of CMV infection, while focusing on GVHD and the use of immunosuppressants, in 103 children who had received CBT. Among the patients, 92.2% were positive for CMV serology, while CMV antigenemia was observed in 68.9% and CMV disease developed in 26.2%. CMV enterocolitis was the most common, followed by retinitis and pneumonia. Patients with positive CMV serology and grade II to IV GVHD were independently associated with CMV antigenemia. Recurrent CMV antigenemia was observed significantly more frequently in patients with extensive chronic GVHD. Patients with CMV disease showed significantly worse overall survival, relapse-free survival, and non-relapse mortality than those without CMV disease. In conclusion, CMV infection is common post-CBT in countries with a high rate of CMV seropositivity in the general population and is related to worse outcomes. GVHD severity is associated with the development and recurrence of CMV infection. Thus, efforts need to be made to prevent CMV infection in children post-CBT. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to report our single-center experience of allogeneic hematopoietic cell transplantation (HCT), which has been the only curative option for certain patients with lethal primary immunodeficiencies (PIDs).Methods: We summarized the results of HCT performed for patients with PIDs for 11 consecutive years from 2006 to 2016 at Samsung Medical Center, Seoul, Korea. Twenty-six patients with PIDs received HCT. Most had chronic granulomatous disease (42.3%), Wiskott Aldrich syndrome (15.4%), or severe combined immunodeficiency (11.5%).Results: Nine patients (34.6%) received HCT during the former half period and 17 patients (65.4%) during the latter half period. Donor types were categorized as: matched sibling donor (n = 5), unrelated donor (n = 17), and familial mismatched donor (FMMD) (n = 4). Unrelated HCT and FMMD transplantation were increasingly performed in the latter half period compared to the first (5 vs. 16, P = 0.034). Five patients experienced initial engraftment failure, but all of them were eventually engrafted after additional HCTs. The 3-year probability of overall survival was 72.0%. Seven patients (26.9%) died, and the causes of death were bacterial sepsis (n = 4), pneumonia (n = 1), chronic graft-versus-host disease (GVHD) (n = 1), and diffuse alveolar hemorrhage (n = 1). Two patients with bacterial sepsis and a patient with pneumonia also had chronic GVHD. Unrelated HCT and use of methotrexate were associated with poor outcome. Complete chimerism was attained in 85.0% at 1 year after HCT.Conclusion: PID candidates have been increasingly identified for allogeneic HCT in Korea, and the majority of them could be cured by HCT. Establishment of a systematic registry of PID patients for HCT is needed. [ABSTRACT FROM AUTHOR]

We reviewed the medical records of five patients with T-B+NK- severe combined immunodeficiency (SCID) who received minimal dose allogeneic hematopoietic cell transplantation (HCT) (total nucleated cell count (TNC) lower than 1.0 × 108/kg). Patients were administered a median of 5.0 mL of bone marrow or peripheral blood without conditioning (in four) or with anti-thymocyte globulin alone (in one). Three patients received HCT from a matched sibling donor, one from unrelated donor, and one from familial mismatched donor. The median TNC and CD34+ cells were 0.54 (0.29–0.84) × 108/kg and 0.61 (0.35–0.84) × 106/kg, respectively. Engraftment was achieved in all. Total T cell, CD4+ cell, and CD8+ cell recovery was obtained within a year in four, and immunoglobulin replacement was discontinued in all. All patients survived, exhibiting stable donor chimerism. We obtained sufficient therapeutic effects with minimal dose transplantation without intensive conditioning in patients with T-B+NK- SCID. • Patients with SCID were administered a median of 5.0 mL of BM or PB grafts. • The median TNC and CD34+ cells were 0.54 × 108/kg and 0.61 × 106/kg, respectively. • Except for one patient, T cell recovery was obtained within a year. • IVIg replacement was discontinued in all patients at a median of 4 months. • All survived without disease recurrence, exhibiting stable donor chimerism. [ABSTRACT FROM AUTHOR]

Hematopoietic stem cell transplantation (HSCT) is a curative therapy for severe aplastic anemia (SAA); however, the optimal conditioning regimen for HSCT with an unrelated donor has not yet been defined. A previous study using a fludarabine (FLU), cyclophosphamide (Cy), and antithymocyte globulin (ATG) conditioning regimen (study A: 50 mg/kg Cy once daily i.v. on days −9, −8, −7, and −6; 30 mg/m 2 FLU once daily i.v. on days −5, −4, −3, and −2; and 2.5 mg/kg of ATG once daily i.v. on days −3, −2, and −1) demonstrated successful engraftment (100%) but had a high treatment-related mortality rate (32.1%). Therefore, given that Cy is more toxic than FLU, we performed a new phase II prospective study with a reduced-toxicity regimen (study B: 60 mg/kg Cy once daily i.v. on days −8 and −7; 40 mg/m 2 FLU once daily i.v. on days −6, −5, −4, −3, and −2; and 2.5 mg/kg ATG once daily i.v. on 3 days). Fifty-seven patients were enrolled in studies A (n = 28) and B (n = 29), and donor type hematologic recovery was achieved in all patients in both studies. The overall survival (OS) and event-free survival (EFS) rates of patients in study B was markedly improved compared with those in study A (OS: 96.7% versus 67.9%, respectively, P = .004; EFS: 93.3% versus 64.3%, respectively, P = .008). These data show that a reduced-toxicity conditioning regimen with FLU, Cy, and ATG may be an optimal regimen for SAA patients receiving unrelated donor HSCT. [ABSTRACT FROM AUTHOR]

Abstract: A 17‐year‐old male with acute lymphoblastic leukemia developed severe hematuria and scrotal swelling after haploidentical hematopoietic cell transplantation (HCT). Urine culture was negative. BK virus and adenovirus were negative. However, Ureaplasma urealyticum was detected. He showed dramatic improvement after doxycycline treatment. This is the first report in the literature of hemorrhagic cystitis caused by U. urealyticum in a HCT recipient. In HCT recipients with hemorrhagic cystitis, U. urealyticum should be considered as a potential cause. [ABSTRACT FROM AUTHOR]

Neurologic complications are serious complications after hematopoietic stem cell transplantation (HSCT) and significantly contribute to morbidity and mortality. The purpose of this study was to investigate the clinical features and prognosis in pediatric patients who had neurologic complications after allogeneic HSCT. We retrospectively reviewed the medical records of children and adolescents (19 years old or younger) who underwent allogeneic HSCT at our institution from 2000 to 2012. A total of 383 patients underwent 430 allogeneic transplantations. Among them, 73 episodes of neurologic complications occurred in 70 patients. The cumulative incidence of neurologic complications at day 400 was 20.0%. Almost two thirds of the episodes (63.0%, 46 of 73) occurred within 100 days after transplantation. Calcineurin inhibitor–related neurotoxicity was observed as the most common cause of neurotoxicity (47.9%, 35 of 73) and was significantly associated with earlier onset neurologic complications, seizure, and tremor. It also showed a significant association with lower probability of headache, abnormality of cranial nerve, and neurologic sequelae. In a multivariate analysis, days to neutrophil engraftment after HSCT, extensive chronic graft-versus-host disease (GVHD) and the existence of neurologic sequelae were identified as risk factors for mortality in patients who had neurologic complications (hazard ratio [HR], 1.08; 95% confidence interval [CI], 1.02 to 1.15; P = .011; HR, 5.98; 95% CI, 1.71 to 20.90; P = .005; and HR, 4.37; 95% CI, 1.12 to 17.05; P = .034, respectively). However, there was no significant difference in the 5-year overall survival between the patients who had neurologic complications without sequelae and the patients who did not have any neurologic complications (57.3% versus 61.8%, P = .906). In conclusion, we found that the major significant risk factors for mortality in pediatric recipients with neurologic complications were the existence of neurologic sequelae and extensive chronic GVHD. [ABSTRACT FROM AUTHOR]

Background We analyzed a nationwide registry of pediatric patients with hemophagocytic lymphohistiocytosis ( HLH) in Korea to assess the clinical and genetic features and treatment outcomes in pediatric HLH. Methods The Korea Histiocytosis Working Party retrospectively analyzed data on 251 pediatric patients diagnosed with HLH between 1996 and 2011. Results In the study cohort, 25 cases were categorized with familial HLH, 64 with presumed secondary HLH, and 162 with unspecified HLH. Of 217 evaluable patients, 91 (42%) had concomitant Epstein-Barr virus infection. Of 238 evaluable patients, central nervous system ( CNS) involvement, which was more frequent in the familial group, was evident in 81 cases (34%). Genetic tests revealed a predominant UNC13D mutation with a high incidence of two recurrent splicing mutations (c.118-308C>T and c.754-1G>C). The 5-yr overall survival rate was 68% (38% in the familial group and 81% in the presumed secondary group). The 5-yr overall survival rate among 32 patients who underwent allogeneic hematopoietic stem cell transplantation was 64%. In multivariate analysis, a younger age at diagnosis, severe transaminasemia, and a coagulation abnormality were independent prognostic factors for survival. Responses during initial treatments were also significant indicators of outcome. Conclusion Our study showed the unique predominance of a UNC13D mutation and vulnerability to Epstein-Barr virus infection in Korean children with HLH and emphasizes the prognostic significance of age, liver dysfunction, and treatment responses in this disease. A multicenter prospective trial that builds on the present results is warranted to identify subgroups of patients with a poor prognosis and identify optimal treatments. [ABSTRACT FROM AUTHOR]

No abstract available [ABSTRACT FROM AUTHOR]

To overcome the limitations of allogeneic hematopoietic stem cell transplantation (HSCT), we conducted a study to identify a strategy for enhancing hematopoietic stem cell (HSC) engraftment during HSCT. Co-transplantation experiments with mesenchymal stem cells (MSCs) derived from adult human tissues including bone marrow (BM), adipose tissue (AT), and umbilical cord blood (CB) were conducted. We showed that AT-MSCs and CB-MSCs enhanced the engraftment of HSCs as effectively as BM-MSCs in NOD/SCID mice, suggesting that AT-MSCs and CB-MSCs can be used as alternative stem cell sources for enhancing the engraftment and homing of HSCs. CB-MSCs derived from different donors showed different degrees of efficacy in enhancing the engraftment of HSCs. The most effective CB-MSCs showed higher proliferation rates and secreted more MCP-1, RANTES, EGF, and VEGF. Our results suggest that AT-MSCs and CB-MSCs could be alternative stem cell sources for co-transplantation in HSCT. Furthermore, in terms of MSCs’ heterogeneity, characteristics of each population of MSCs are considerable factors for selecting MSCs suitable for co-transplantation with HSC. [ABSTRACT FROM AUTHOR]

Respiratory viruses ( RVs) are a known cause of morbidity and mortality after hematopoietic stem cell transplantation ( HSCT). In this retrospective study, we focused on the first 28 d after transplantation in pediatric HSCT recipients and showed that a multiplex PCR assay significantly increased RV detection compared with a viral culture method. Among 176 pediatric HSCT recipients, 84 with respiratory symptoms within one yr after HSCT were tested by viral culture or multiplex PCR. Within 28 d after HSCT, nine patients were infected with RVs; the incidence of a first episode of RV infection within 28 d after HSCT was 5.1%. Eight patients recovered without complications. However, one patient died of adenovirus ( Ad V) pneumonia with pulmonary hemorrhage; the mortality rate of RV infection within 28 d after HSCT was 0.57%. In the nine patients with RV infection, five different types of RV were identified, either alone or with another RV. These were corona virus ( Co V), rhinovirus ( Rh V) and respiratory syncytial virus combined with Co V; Ad V combined with Rh V; and parainfluenza virus. Viral culture detected only one case of RV infection, while multiplex PCR detected eight, suggesting that screening of respiratory infections using multiplex PCR is better than the conventional culture method. [ABSTRACT FROM AUTHOR]

The role of unrelated donor HSCT for children with de novo AML in CR1 is controversial. We performed this study to investigate the feasibility of unrelated donor HSCT who initially had intermediate‐ or high‐risk cytogenetics. We retrospectively reviewed medical records of patients with AML who received unrelated HSCT in CR1 at Samsung Medical Center between November 2001 and January 2012. Patients were allocated based on karyotype at diagnosis as follows: (a) low‐risk: inv(16), t(16;16), t(8;21), and t(15;17); (b) high‐risk: ‐5, 5q‐, ‐7, 3q abnormalities, t(8;16), t(6;9), t(6;11), t(6;21), t(10;11), complex karyotype (≥3 abnormalities), and acute megakaryocytic leukemia without t(1;22); and (c) IR: all the other karyotypes including normal. Patients in intermediate‐ or high‐risk group who were transplanted with either unrelated CB or matched unrelated BM/mobilized PB in their CR1 were included in this study. The projected OS and EFS rates were 74.9% and 71.1%, respectively, with a median follow‐up of 87.3 months after transplantation. The EFS was 70.1%, 80.7%, and 73.9% for CB, BM, and mobilized PB groups, respectively (P = 0.89), and 73.9% and 70.6% for IR and high‐risk groups (P = 0.76). The leading cause of death was relapse (n = 8), and only one patient died from non‐relapse cause. Unrelated donor HSCT seems a feasible approach for children with intermediate‐ or high‐risk AML in CR1. Relapse remains the leading cause of treatment failure among these patients. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained a mistake in the 7th author’s given name. The correct version is presented above. [ABSTRACT FROM AUTHOR]