• Clinical and Experimental Pediatrics
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• v.56 no.1
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• pp.26-31
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• 2013

Purpose: Lymphocyte subset recovery is an important factor that determines the success of hematopoietic stem cell transplantation (HSCT). Temporal differences in the recovery of lymphocyte subsets and the factors influencing this recovery are important variables that affect a patient's posttransplant immune reconstitution, and therefore require investigation. Methods: The time taken to achieve lymphocyte subset recovery and the factors influencing this recovery were investigated in 59 children who had undergone HSCT at the Department of Pediatrics, The Catholic University of Korea Seoul St. Mary's Hospital, and who had an uneventful follow-up period of at least 1 year. Analyses were carried out at 3 and 12 months post-transplant. An additional study was performed 1 month post-transplant to evaluate natural killer (NK) cell recovery. The impact of pre- and post-transplant variables, including diagnosis of Epstein-Barr virus (EBV) DNAemia posttransplant, on lymphocyte recovery was evaluated. Results: The lymphocyte subsets recovered in the following order: NK cells, cytotoxic T cells, B cells, and helper T cells. At 1 month post-transplant, acute graft-versus-host disease was found to contribute significantly to the delay of $CD16^+/56^+$ cell recovery. Younger patients showed delayed recovery of both $CD3^+/CD8^+$ and $CD19^+$ cells. EBV DNAemia had a deleterious impact on the recovery of both $CD3^+$ and $CD3^+/CD4^+$ lymphocytes at 1 year post-transplant. Conclusion: In our pediatric allogeneic HSCT cohort, helper T cells were the last subset to recover. Younger age and EBV DNAemia had a negative impact on the post-transplant recovery of T cells and B cells.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1154-1158
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• 2013

Ganciclovir resistance of human cytomegalovirus is associated with mutations in the viral UL97 gene and poses severe problems for immunocompromised patients. In this study, PCR-based restriction fragment length polymorphism and sequencing analyses detected the UL97 D605E mutation in all five clinical isolates from patients with ganciclovir-resistant human cytomegalovirus infection during prolonged ganciclovir therapy, whereas the M460V mutation was only present in 1 of 5 isolates. On the other hand, the detection rates of the D605E mutation in the stored available DNA samples from the donor and allogeneic stem cell transplantation recipients were 66.7% and 93.7%, respectively, suggesting that the presence of D605E mutation was not associated with the ganciclovir exposure. Although the D605E mutation may not be related to ganciclovir resistance, we suggest that this mutation could be an important molecular marker of human cytomegalovirus evolution in East Asian countries. Moreover, the restriction fragment length polymorphism method using the restriction enzyme HaeIII, which is generally used to detect the UL97 A591V mutation, could also detect the D605E mutation and may therefore be a useful tool for future research on the investigation of UL97 gene mutations.

• Clinical and Experimental Pediatrics
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• v.58 no.6
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• pp.199-205
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• 2015

Severe aplastic anemia (SAA) is a life-threatening disorder for which allogeneic hematopoietic stem cell transplantation (HSCT) is the current available curative treatment. HSCT from matched sibling donors (MSDs) is the preferred therapy for children with acquired SAA. For patients who lack MSDs, immunosuppressive therapy (IST) is widely accepted as a first-line treatment before considering HCT from an unrelated donor (URD). Given the recent progress in HSCT using URDs for childhood SAA, well-matched URDs became a realistic alternative for pediatric patients who have no suitable related donors and who are refractory to IST. However, it is quite challenging to treat patients with refractory SAA who lack suitable related or URDs. Even though haploidentical HSCT from genetically mismatched family members seemed to be an attractive procedure with the amazing benefit of readily available donors for most patients, early attempts were disappointing because of refractory graft-versus-host disease (GVHD) and excessively high transplant-related mortality. Recent advances with effective ex vivo depletion of T cells or unmanipulated in vivo regulation of T cells, better supportive care, and optimal conditioning regimens have significantly improved the outcome of haploidentical transplant. Besides considerable progress in the treatment of malignant diseases, recent emerging evidences for haploidentical HSCT in SAA has provided additional therapeutic options for patients with refractory diseases. Further improvements to decrease the rates of graft failure, GVHD, and infectious complications will facilitate the emergence of haploidentical HSCT as a front-line therapy for treating acquired SAA in children and adolescents who have no suitably matched donors.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.49-57
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• 2017

This is a convergence study about influences of hematopoietic stem cell transplantation on children growth. For this explanatory survey research, data were collected with medical record of 112 children with malignant and hematological diseases received HSCT from February to March, 2009. To analyze the growth after HSCT, mixed-effects model was used. The mean SDS of height and weight were negative values in HSCT. The mean value of SDS were significantly lower in autologous HSCT group by height(p=0.0008) and weight(p= 0.0012). Significant factors on changes of SDS of height growth were age at HSCT(p=0.0251), autologous HSCT(p=0.0020) and total dose of steroid in allogeneic HSCT (p=0.0403) and age at HSCT(p=0.0042), autologous HSCT(p=0.0035), and duration of TPN(p=0.0159) for weight growth. According to the results, we must learn to recognize the predicting growth impairment after HSCT in children. regarding nursing interventions should be conducted in the care of these children.

• Clinical and Experimental Pediatrics
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• v.55 no.3
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• pp.100-106
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• 2012

Purpose: The survival rate for childhood acute lymphoblastic leukemia (ALL) has improved significantly. However, overall prognosis for the 20 to 25% of patients who relapse is poor, and allogeneic hematopoietic stem cell transplantation (HSCT) offers the best chance for cure. In this study, we identified significant prognostic variables by analyzing the outcomes of allogeneic HSCT in ALL patients in second complete remission (CR). Methods: Fifty-three ALL patients (42 men, 79%) who received HSCT in second CR from August 1991 to February 2009 were included (26 sibling donor HSCTs, 49%; 42 bone marrow transplantations, 79%). Study endpoints included cumulative incidence of acute and chronic graft-versus-host disease (GVHD), relapse, 1-year transplant-related mortality (TRM), disease-free survival (DFS), and overall survival (OS). Results: Cumulative incidences of acute GVHD (grade 2 or above) and chronic GVHD were 45.3% and 28.5%, respectively. The estimated 5-year DFS and OS for the cohort was $45.2{\pm}6.8%$ and $48.3{\pm}7%$, respectively. Only donor type, i.e., sibling versus unrelated, showed significant correlation with DFS in multivariate analysis ($p$=0.010). The rates of relapse and 1 year TRM were $28.9{\pm}6.4%$ and $26.4{\pm}6.1%$, respectively, and unrelated donor HSCT ($p$=0.002) and HLA mismatch ($p$=0.022) were significantly correlated with increased TRM in univariate analysis. Conclusion: In this single institution study spanning more than 17 years, sibling donor HSCT was the only factor predicting a favorable result in multivariate analysis, possibly due to increased TRM resulting from unrelated donor HSCT.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.713-722
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• 1996

Poor long term patient survival (60% at 2 years) in lung allograft recipients are mainly due to rejection and complications associated with the use of nonspecific immunosuppressants. Better means to achieve waft acceptance is desperately needed. 1 have investigated whether mixed allogeneic chimerism in the form of bone marrow stem cell engraftment would induce donor-specific tolerance for lung allografts. Fisher (F344) and Wistar Forth (WF)rats were lethally irradiated (1100c0y) and reconstituted with a mixture of T-cell depleted syngeneic and allogeneic bone marrow (F344+WFIWF, ACI +F344- F344). After Mixed chimerism was documented by peripheral blood Ipnphocyte typing at 28 days, orthotopic left single lung transplantation was performed, using donor-s ecific or third party allografts. No immunosuppressants were administered. Graft rejection was monitored by chest rentgenography, and con- firmed by histology Mixed chimeric rats accepted lung allografts permanently, and it was not strain specific effect. Tolerance was all or none phenomenon which had nothing to do with the percentage of chimerlsm. Mixed chimeras rejected third party allografts in less than 10 days, a time course similar to that of unmanipulated controls. No acute or chronic rejection was observed in donor specific grafts more than 150 days posttransplant. These data suggest that mixed chimerism in the form of bone marrow stem cell engraftment results in stable, systemic donor-specific transplantation tolerance for lung allografts.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.178-185
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• 2005

Purpose : The purpose of this study was to evaluate the outcome of children with juvenile myelomonocytic leukemia(JMML) treated with allogeneic hematopoietic stem cell transplantation(allo-HSCT). Methods : Eleven JMML patients aged 8-39 months underwent allo-HSCT. The sources of grafts were unrelated donors(n=7), HLA-matched siblings(n=3) and an HLA 1-antigen mismatched familial donor. All patients had received chemotherapy ${\pm}13$-cis-retinoic acid(CRA) before transplant, and CRA was used, posttransplant, in six patients. Results : Only three patients were in complete remission(CR) at the time of transplantation. Initial chimeric status revealed complete donor chimerism(CC) in five patients, mixed chimerism(MC) in five and autologous recovery(AR) in one. One patient with MC having persistent splenomegaly eventually turned to CC and CR after rapid tapering of cyclosporine, combined with daily use of CRA. An AR case relapsed shortly after transplant but was rescued with second, unrelated cord blood transplantation. Ultimately, six patients are alive, event-free, with a median follow-up of 15.5 months posttransplant. All three deaths occurred in patients who failed to achieve CC, leading to disease progression. Conclusion : We suggest that graft-versus-leukemia effect play an important role and CRA a possible role in posttransplant leukemic involution in JMML. In patients whose leukemic burden is still high with MC after transplant, early tapering of immunosuppressants and introduction of CRA might provide a chance of a cure for some patients.

• IMMUNE NETWORK
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• v.14 no.2
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• pp.89-99
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• 2014

Graft-versus-host disease (GVHD) is a fatal complication that occurs after allogeneic hematopoietic stem cell transplantation. To understand the dynamics of CD4 and CD8 T cell production of IFN-${\gamma}$ and IL-17 during GVHD progression, we established a GVHD model by transplanting T cell-depleted bone marrow (TCD-BM) and purified T cells from B6 mice into irradiated BALB.B, creating an MHC-matched but minor histocompatibility (H) antigen-mismatched transplantation (B6 ${\rightarrow}$ BALB.B GVHD). Transplantation-induced GVHD was confirmed by the presence of the appropriate compositional changes in the T cell compartments and innate immune cells in the blood and the systemic secretion of inflammatory cytokines. Using this B6 ${\rightarrow}$ BALB.B GVHD model, we showed that the production of IFN-${\gamma}$ and IL-17 by CD4 T cells preceded that by CD8 T cells in the spleen, mesenteric lymph node, liver, and lung in the BALB.B GVHD host, and Th1 differentiation predated Th17 differentiation in all organs during GVHD progression. Such changes in cytokine production were based on changes in cytokine gene expression by the T cells at different time points during GVHD development. These results demonstrate that both IFN-${\gamma}$ and IL-17 are produced by CD4 and CD8 T cells but with different kinetics during GVHD progression.

• Clinical and Experimental Pediatrics
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• v.54 no.3
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• pp.111-116
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• 2011

Childhood chronic myelogenous leukemia (CML) is a rare hematologic disease, with limited literature on the methods of treatment. Previously, allogeneic hematopoietic stem cell transplantation (HSCT) was considered the only curative treatment for this disease. Treatment with imatinib, a selective inhibitor of the BCR-ABL tyrosine kinase (TKI), has resulted in prolonged molecular response with limited drug toxicity. Imatinib is now implemented in the primary treatment regimen for children, but the paucity of evidence on its ability to result in permanent cure and the potential complications that may arise from long-term treatment with TKIs have prevented imatinib from superseding HSCT as the primary means of curative treatment in children. The results of allogeneic HSCT in children with CML are similar to those observed in adults; HSCT-related complications such as transplant-related mortality and graft-versus-host disease remain significant challenges. An overall consensus has been formed with regards to the need for HSCT in patients with imatinib resistance or those with advanced-phase disease. However, issues such as when to undertake HSCT in chronic-phase CML patients or how best to treat patients who have relapsed after HSCT are still controversial. The imatinib era calls for a reevaluation of the role of HSCT in the treatment of CML. Specific guidelines for the treatment of pediatric CML have not yet been formulated, underscoring the importance of prospective studies on issues such as duration of imatinib treatment, optimal timing of HSCT and the type of conditioning utilized, possible treatment pre-and post-HSCT, and the role of second-generation TKIs.

• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1211-1215
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• 2006

Purpose : In this study, we analyzed the short term changes of thyroid function, incidence and risk factors of thyroid dysfunction soon after allogeneic hematopoietic stem cell transplantation (HSCT) in children. Methods : We enrolled 80 pediatric patients following allogeneic HSCT, at the Catholic HSCT center between January, 2004 and February, 2006. Serum TSH (thyroid stimulating hormone), total serum thyroxine and total serum triiodothyronine levels were systematically measured in 80 patients before the HSCT, and at 1 month, 6 months and 12 months after HSCT. Results : Thyroid function statistically decreased at 1 month after HSCT(P<0.001). Thyroid dysfunction at 1 month was observed in 43 (54 percent) of 80 patients, 31 (39 percent) of whom presented with euthyroid sick syndrome (ETS). Thyroid dysfunction was normalized within 1 year after HSCT. In univariate analysis, malignant disease and the presence of acute graft-versus-host disease (grade ${\geq}II$) were risk factors for ETS (P=0.04, 0.01 respectively). In multivariate analysis, we could not detect an independent risk factor for ETS (P=0.19, 0.06 respectively). Conclusion : The present study suggests that the incidence of thyroid dysfunction is high after allogeneic HSCT. Therefore, regular monitoring of thyroid hormone levels after HSCT is required.