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1.
Article in English | WPRIM | ID: wpr-913833

ABSTRACT

Purpose@#Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. @*Materials and Methods@#Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. @*Results@#Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). @*Conclusion@#This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.

2.
Article in English | WPRIM | ID: wpr-889734

ABSTRACT

Purpose@#Recent cooperative trials in pediatric acute lymphoblastic leukemia (ALL) report long-term event-free survival (EFS) of greater than 80%. In this study, we analyzed the outcome and prognostic factors for patients with precursor B cell ALL (n=405) diagnosed during a 10-year period (2005-2015) at our institution. @*Materials and Methods@#All patients were treated with a uniform institutional regimen based on four risk groups, except for steroid type; patients diagnosed up till 2008 receiving dexamethasone, while subsequent patients received prednisolone. None of the patients received cranial irradiation in first complete remission. @*Results@#The 10-year EFS and overall survival was 76.3%±2.3% and 85.1%±1.9%. Ten-year cumulative incidence of relapse, any central nervous system (CNS) relapse and isolated CNS relapse was 20.8%±2.2%, 3.7%±1.1% and 2.5%±0.9% respectively. A comparison of established, good prognosis genetic abnormalities showed that patients with high hyperdiploidy had significantly better EFS than those with ETV6-RUNX1 rearrangement (10-year EFS of 91.2%±3.0% vs. 79.5%±4.4%, p=0.033). For the overall cohort, male sex, infant ALL, initial CNS involvement, and Philadelphia chromosome (+) ALL were significant factors for lower EFS in multivariate study, while high hyperdiploidy conferred favorable outcome. For high and very high risk patients (n=231), high hyperdiploidy was the only significant factor for EFS in multivariate study. @*Conclusion@#Regarding good prognosis genetic abnormalities, patients with high hyperdiploidy had significantly better outcome than ETV6-RUNX1 (+) patients. High hyperdiploidy was a major, favorable prognostic factor in the overall patient group, as well as the subgroup of patients with higher risk.

3.
Article in English | WPRIM | ID: wpr-897438

ABSTRACT

Purpose@#Recent cooperative trials in pediatric acute lymphoblastic leukemia (ALL) report long-term event-free survival (EFS) of greater than 80%. In this study, we analyzed the outcome and prognostic factors for patients with precursor B cell ALL (n=405) diagnosed during a 10-year period (2005-2015) at our institution. @*Materials and Methods@#All patients were treated with a uniform institutional regimen based on four risk groups, except for steroid type; patients diagnosed up till 2008 receiving dexamethasone, while subsequent patients received prednisolone. None of the patients received cranial irradiation in first complete remission. @*Results@#The 10-year EFS and overall survival was 76.3%±2.3% and 85.1%±1.9%. Ten-year cumulative incidence of relapse, any central nervous system (CNS) relapse and isolated CNS relapse was 20.8%±2.2%, 3.7%±1.1% and 2.5%±0.9% respectively. A comparison of established, good prognosis genetic abnormalities showed that patients with high hyperdiploidy had significantly better EFS than those with ETV6-RUNX1 rearrangement (10-year EFS of 91.2%±3.0% vs. 79.5%±4.4%, p=0.033). For the overall cohort, male sex, infant ALL, initial CNS involvement, and Philadelphia chromosome (+) ALL were significant factors for lower EFS in multivariate study, while high hyperdiploidy conferred favorable outcome. For high and very high risk patients (n=231), high hyperdiploidy was the only significant factor for EFS in multivariate study. @*Conclusion@#Regarding good prognosis genetic abnormalities, patients with high hyperdiploidy had significantly better outcome than ETV6-RUNX1 (+) patients. High hyperdiploidy was a major, favorable prognostic factor in the overall patient group, as well as the subgroup of patients with higher risk.

4.
Article in English | WPRIM | ID: wpr-914060

ABSTRACT

X-linked inhibitor of apoptosis protein (XIAP) deficiency is a rare immunodeficiency disorder. A 13-month-old boy was diagnosed with pure red cell aplasia (PRCA) and treated with steroid and cyclosporine. Bone marrow showed diminished erythroid precursors, and positive results for Parvovirus B19 and Cytomegalovirus (CMV) infection. A genetic study of Diamond-Blackfan anemia was negative. Five months later, he was admitted due to fever and lymphadenopathy. PCR showed still positive for the Parvovirus, CMV, and Epstein-Barr virus (EBV). He was diagnosed with diffuse large B-cell lymphoma that was positive for EBV. The patient received chemotherapy with R-CHOP, and achieved complete remission. Immunoglobulin (Ig) levels were within an age-matched normal range until the completion of chemotherapy. Subsequently, he was admitted nine times due to recurrent pneumonia and acute otitis media between two and eight years old. We reanalyzed the Ig levels and lymphocyte subsets: IgG, IgA, and IgM were 30 mg/dL, below 1.0 mg/dL, and 36 mg/dL, respectively. Lymphocyte subsets showed nearly absent CD19 (+) cells, but T- and NK cell counts were within normal ranges. A genetic study showed a hemizygous inframe deletion mutation in exon 4 of the IAP gene without the SH2D1A mutation, consistent with a XIAP deficiency. Therefore, he was diagnosed with XIAP deficiency. Genetic analysis of his mother, aunt and elder sister showed that they were carriers of the same gene mutation. He receives intravenous Ig regularly with follow-up, and still requires a low dose steroid to maintain hemoglobin level. We report XIAP deficiency as initial presentation of PRCA.

5.
Cancer Research and Treatment ; : 1184-1194, 2021.
Article in English | WPRIM | ID: wpr-913813

ABSTRACT

Purpose@#Effectiveness and safety of clofarabine (one of the treatment mainstays in pediatric patients with relapsed/refractory acute lymphoblastic leukemia [ALL]) was assessed in Korean pediatric patients with ALL to facilitate conditional coverage with evidence development. @*Materials and Methods@#In this multicenter, prospective, observational study, patients receiving clofarabine as mono/combination therapy were followed up every 4-6 weeks for 6 months or until hematopoietic stem cell transplantation (HSCT). Response rates, survival outcomes, and adverse events were assessed. @*Results@#Sixty patients (2-26 years old; 65% B-cell ALL, received prior ≥ 2 regimen, 68.3% refractory to previous regimen) were enrolled and treated with at least one dose of clofarabine; of whom 26 (43.3%) completed 6 months of follow-up after the last dose of clofarabine. Fifty-eight patients (96.7%) received clofarabine combination therapy. Overall remission rate (complete remission [CR] or CR without platelet recovery [CRp]) was 45.0% (27/60; 95% confidence interval [CI], 32.4 to 57.6) and the overall response rate (CR, CRp, or partial remission [PR]) was 46.7% (28/60; 95% CI, 34.0 to 59.3), with 11 (18.3%), 16 (26.7%), and one (1.7%) patients achieving CR, CRp, and PR, respectively. The median time to remission was 5.1 weeks (95% CI, 4.7 to 6.1). Median duration of remission was 16.6 weeks (range, 2.0 to 167.6 weeks). Sixteen patients (26.7%) proceeded to HSCT. There were 24 deaths; 14 due to treatment-emergent adverse events. @*Conclusion@#Remission with clofarabine was observed in approximately half of the study patients who had overall expected safety profile; however, there was no favorable long-term survival outcome in this study.

6.
Article in English | WPRIM | ID: wpr-831569

ABSTRACT

Background@#Hodgkin's lymphoma (HL) constitutes 10%–20% of all malignant lymphomas and has a high cure rate (5-year survival, around 90%). Recently, interest has increased concerning preventing secondary complications (secondary cancer, endocrine disorders) in long-term survivors. We aimed to study the epidemiologic features and therapeutic outcomes of HL in children, adolescents, and young adults in Korea. @*Methods@#We performed a multicenter, retrospective study of 224 patients aged < 25 years diagnosed with HL at 22 participating institutes in Korea from January 2007 to August 2016. @*Results@#A higher percentage of males was diagnosed at a younger age. Nodular sclerosis histopathological HL subtype was most common, followed by mixed cellularity subtype.Eighty-one (36.2%), 101 (45.1%), and 42 (18.8%) patients were classified into low, intermediate, and high-risk groups, respectively. Doxorubicin, bleomycin, vinblastine, dacarbazine was the most common protocol (n = 102, 45.5%). Event-free survival rate was 86.0% ± 2.4%, while five-year overall survival (OS) rate was 96.1% ± 1.4%: 98.7% ± 1.3%, 97.7% ± 1.6%, and 86.5% ± 5.6% in the low, intermediate, and high-risk groups, respectively (P = 0.021). Five-year OS was worse in patients with B-symptoms, stage IV disease, highrisk, splenic involvement, extra-nodal lymphoma, and elevated lactate dehydrogenase level.In multivariate analysis, B-symptoms and extra-nodal involvement were prognostic factors for poor OS. Late complications of endocrine disorders and secondary malignancy were observed in 17 and 6 patients, respectively. @*Conclusion@#This is the first study on the epidemiology and treatment outcomes of HL in children, adolescents, and young adults in Korea. Future prospective studies are indicated to develop therapies that minimize treatment toxicity while maximizing cure rates in children, adolescents, and young adults with HL.

7.
Article in English | WPRIM | ID: wpr-763515

ABSTRACT

Chronic active Epstein-Barr virus (CAEBV) infection is characterized by recurrent infectious mononucleosis (IM)-like symptoms and an unusual pattern of anti-EBV antibodies. We report a boy with CAEBV who progressed to aggressive hemophagocytic lymphohistiocytosis (HLH) with NK cell neoplasm. A 19-year-old adolescent boy was admitted with fever and a history of recurrent IM-like symptoms following mosquito bites since the age of 6 years. His condition was diagnosed as CAEBV with atypical lymphocytosis and an unusual pattern of anti-EBV antibodies. His symptoms subsided during treatment with steroids and cyclosporine, although the EBV genome load kept increasing for several years. He was re-admitted after follow-up loss for 8 years, and his clinical and laboratory findings confirmed HLH and high titer of the EBV genome. Bone marrow analysis with flow cytometry showed hemophagocytosis with compatible NK cell neoplasm. He rapidly progressed to pulmonary infection and expired soon after. We conclude that hematopoietic stem cell transplantation may be a potential therapeutic modality for treating CAEBV before serious EBV manifestations.


Subject(s)
Adolescent , Antibodies , Bone Marrow , Culicidae , Cyclosporine , Epstein-Barr Virus Infections , Fever , Flow Cytometry , Follow-Up Studies , Genome , Hematopoietic Stem Cell Transplantation , Herpesvirus 4, Human , Humans , Hypersensitivity , Infectious Mononucleosis , Killer Cells, Natural , Lymphocytosis , Lymphohistiocytosis, Hemophagocytic , Male , Steroids , Young Adult
8.
Article in English | WPRIM | ID: wpr-719418

ABSTRACT

PURPOSE: Dexrazoxane has been used as an effective cardioprotector against anthracycline cardiotoxicity. This study intended to analyze cardioprotective efficacy and secondary malignancy development, and elucidate risk factors for secondary malignancies in dexrazoxane-treated pediatric patients. MATERIALS AND METHODS: Data was collected from 15 hospitals in Korea. Patients who received any anthracyclines, and completed treatment without stem cell transplantation were included. For efficacy evaluation, the incidence of cardiac events and cardiac event-free survival rates were compared. Data about risk factors of secondary malignancies were collected. RESULTS: Data of total 1,453 cases were analyzed; dexrazoxane with every anthracyclines group (D group, 1,035 patients) and no dexrazoxane group (non-D group, 418 patients). Incidence of the reported cardiac events was not statistically different between two groups; however, the cardiac event-free survival rate of patients with more than 400 mg/m2 of anthracyclines was significantly higher in D group (91.2% vs. 80.1%, p=0.04). The 6-year cumulative incidence of secondary malignancy was not different between both groups after considering follow-up duration difference (non-D, 0.52%±0.37%; D, 0.60%±0.28%; p=0.55). The most influential risk factor for secondary malignancy was the duration of anthracycline administration according to multivariate analysis. CONCLUSION: Dexrazoxane had an efficacy in lowering cardiac event-free survival rates in patients with higher cumulative anthracyclines. As a result of multivariate analysis for assessing risk factors of secondary malignancy, the occurrence of secondary malignancy was not related to dexrazoxane administration.


Subject(s)
Anthracyclines , Cardiotoxicity , Dexrazoxane , Disease-Free Survival , Follow-Up Studies , Humans , Incidence , Korea , Multivariate Analysis , Neoplasms, Second Primary , Risk Factors , Stem Cell Transplantation
9.
Blood Research ; : 45-51, 2019.
Article in English | WPRIM | ID: wpr-739435

ABSTRACT

BACKGROUND: Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is a subset of ALL with poor prognosis. Here, we analyzed the outcomes and prognostic factors of children with Ph+ ALL who received imatinib and chemotherapy followed by allogeneic hematopoietic cell transplantation (HCT) in first complete remission (CR). METHODS: Thirty-one Ph+ ALL patients (female 10) diagnosed from January 2005 to December 2016 were included in the study. All patients were treated with imatinib and chemotherapy before HCT. Bone marrow (BM) evaluations included real-time quantitative polymerase chain reaction (RQ-PCR) study of the BCR-ABL1 fusion transcript. All patients received HCT with total body irradiation (TBI)-based conditioning at a median of 6.4 (range, 4.2–47.1) months from diagnosis. RESULTS: Compared to values at diagnosis, the median decrement of RQ-PCR value post-consolidation, and prior to HCT was −3.7 Log and −4.8 Log, respectively. The 5-year event-free survival (EFS) and overall survival of the patients were 64.5±9.4% (20/31) and 75.0±8.3% (23/31) respectively. Events included relapse (N=5) and death in CR post-HCT (N=6). The 5-year incidence of molecular relapse was 30.9±9.1% (9/31). An RQ-PCR decrement of at least −4 Log post-consolidation significantly predicted lower incidence of molecular relapse: 7.7±7.7% for ≥−4 Log decrement, 50.0±13.8% for <−4 Log decrement (P=0.027). CONCLUSION: Decrement in RQ-PCR for the BCR-ABL1 transcript that was determined after consolidation was the only significant prognostic factor for incidence of molecular relapse. In the post-induction TKI initiation setting, steadfast imatinib treatment during consolidation may allow for optimum post-HCT outcomes.


Subject(s)
Bone Marrow , Cell Transplantation , Child , Diagnosis , Disease-Free Survival , Drug Therapy , Humans , Imatinib Mesylate , Incidence , Philadelphia Chromosome , Polymerase Chain Reaction , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Prognosis , Recurrence , Transplants , Whole-Body Irradiation
10.
Article in English | WPRIM | ID: wpr-739121

ABSTRACT

We reviewed our leukemia database to reclassify 610 patients previously diagnosed as having acute myeloid leukemia (AML) according to the updated 2016 WHO classification. Nine patients were categorized as having myelodysplastic syndrome and myeloid neoplasms with germline predisposition. AML with recurrent genetic abnormalities accounted for 57.4% (345/601) of the patients under the 2016 WHO classification. AML with mutated NPM1 was the most common form (16.5%), with the majority associated with monocytic differentiation (63.6%). AML with double CEBPA mutations accounted for 8.3% of these cases, and the majority were previously diagnosed as AML with/without maturation (78.0%). These newly classified mutations were mutually exclusive without overlapping with other forms of AML with recurrent genetic abnormalities. AML with mutated NPM1 and AML with myelodysplasia-related changes comprised the oldest patients, whereas AML with RUNX1-RUNX1T1 included the youngest patients. The leukocyte count was highest in AML with mutated NPM1, and the percentage of peripheral blood blasts was the highest in AML with double CEBPA mutations. Our results indicate that implementation of the 2016 WHO classification of AML would not pose major difficulties in clinical practice. Hematopathologists should review and prepare genetic tests for the new classification, according to their clinical laboratory conditions.


Subject(s)
Classification , Humans , Leukemia , Leukemia, Myeloid, Acute , Leukocyte Count , Myelodysplastic Syndromes
11.
Infection and Chemotherapy ; : 183-187, 2019.
Article in English | WPRIM | ID: wpr-914574

ABSTRACT

This retrospective study was performed to determine the seroprevalence of hepatitis A virus (HAV) in children and adolescents with hematologic malignancies after the completion of chemotherapy and hematopoietic cell transplantation (HCT). Of 97 enrolled patients, 60 (61.9%) were seropositive for HAV. The seroprevalences in patients undergoing chemotherapy and HCT were 60.3% (41/68) and 65.5% (19/29), respectively (P = 0.628). No significant factors associated with seropositivity for HAV after chemotherapy and HCT were identified. Anti-HAV tests and HAV re-vaccinations can be considered in children and adolescents with underlying hematologic malignancies after chemotherapy and HCT based on the anti-HAV results.

12.
Laboratory Medicine Online ; : 114-118, 2018.
Article in Korean | WPRIM | ID: wpr-715908

ABSTRACT

Hereditary spherocytosis (HS) is caused by mutations in the SPTA1, SPTB, ANK1, SLC4A1, and EPB42 genes, all of which encode erythrocyte membrane proteins. Mutations in SLC4A1, which encodes band 3 protein, have rarely been reported as the causative factor among Korean patients with HS. Here, we report two Korean patients with HS carrying mutations in SLC4A1. Patient 1 was a 3-year-old girl with unremarkable past and family histories and was evaluated for anemia that was detected after a complete blood count. She was suspected of having HS considering the spherocytosis of her peripheral blood smear, increased osmotic fragility, hemolytic features in blood chemistry tests, and splenomegaly. Sequence analysis revealed that the patient harbored a single heterozygous missense mutation, c.2278C>T (p.Arg760Trp) in exon 17 of SLC4A1. Patient 2 was a 23-year-old man who had a prior history of intermittent jaundice. Although the patient did not have anemia, a genetic test for HS was performed due to evidence of hemolytic features in the blood chemistry test, splenomegaly, and a family history of HS. The test confirmed a single heterozygous missense mutation, c.2423G>T (p.Arg808Leu) in exon 18 of SLC4A1.


Subject(s)
Anemia , Anion Exchange Protein 1, Erythrocyte , Blood Cell Count , Chemistry , Child, Preschool , Erythrocyte Membrane , Exons , Female , Humans , Jaundice , Mutation, Missense , Osmotic Fragility , Sequence Analysis , Splenomegaly , Young Adult
13.
Blood Research ; : 145-151, 2018.
Article in English | WPRIM | ID: wpr-714929

ABSTRACT

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for β-thalassemia major (TM) and sickle cell disease (SCD) in children. Graft-versus-host disease (GVHD) and treatment-related mortality (TRM) remain significant challenges to improving survival after HSCT. Here, we analyzed the outcome of TM and SCD patients, who received allogeneic HSCT with myeloablative conditioning at our institution. METHODS: Twenty-two patients (15 TM, 7 SCD), with a median age of 9 years (range, 1.6–16.9), underwent allogeneic HSCT using busulfan, cyclophosphamide and rabbit anti-thymocyte globulin-based conditioning. Cells were derived from either the bone marrow (8 patients), or peripheral blood stem cells (14 patients). The majority of patients received HSCT from a matched sibling donor (N=18). GVHD prophylaxis included cyclosporine and short course methotrexate. RESULTS: All patients achieved donor engraftment. Two SCD patients died from TRM-related grade IV gut GVHD (N=1) or severe bronchiolitis obliterans (BO) (N=1). Cumulative incidence of acute and chronic GVHD was 36.4% and 32.7%, respectively. Veno-occlusive disease (VOD) occurred in 8 patients (36.4%), but resolved in all instances. Epstein-Barr virus (EBV)-related post-transplantation lymphoproliferative disease (PTLD) occurred in 1 patient. The overall survival (OS) was 90.9% (TM 100%, SCD 71.4%), with all patients achieving transfusion independence, while 8 achieved complete donor chimerism. CONCLUSION: Busulfan, cyclophosphamide, and ATG-based conditioning for HSCT of TM and SCD patients did not result in graft failure, although modifications may be required to reduce VOD incidence. Further changes to donor type and cell source prioritization are necessary to minimize TRM and morbidity caused by GVHD.


Subject(s)
Anemia, Sickle Cell , Antilymphocyte Serum , beta-Thalassemia , Bone Marrow , Bronchiolitis Obliterans , Busulfan , Child , Chimerism , Cyclophosphamide , Cyclosporine , Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cells , Hemoglobinopathies , Herpesvirus 4, Human , Humans , Incidence , Methotrexate , Mortality , Siblings , Stem Cells , Tissue Donors , Transplants
15.
Article in English | WPRIM | ID: wpr-101937

ABSTRACT

PURPOSE: ETV6/RUNX1 (+) acute lymphoblastic leukemia (ALL), which is the most common genetic subtype of pediatric ALL, has a favorable prognosis. In this study, we analyzed the outcome of ETV6/RUNX1 (+) ALL patients treated at our institution with the aim of identifying significant prognostic variables. MATERIALS AND METHODS: Sixty-three patients were diagnosed with ETV6/RUNX1 (+) ALL from 2005 to 2011. Prognostic variables studied included minimal residual disease (MRD) as detected by ETV6/RUNX1 (+) fusion, and the presence of additional cytogenetic abnormalities. RESULTS: The 5-year event-free survival was 84.1±4.6%, with 10 patients relapsing at a median of 28.3 months from diagnosis for a 5-year cumulative incidence of relapse of 15.9±4.6%. Multivariate analysis revealed that the presence MRD, as detected by real-time quantitative-polymerase chain reaction or fluorescence in situ hybridization for ETV6/RUNX1 fusion at end of remission induction, and the presence of additional structural abnormalities of 12p (translocations or inversions) negatively affected outcome. Despite treatment such as allogeneic hematopoietic cell transplantation, eight of the 10 relapsed patients died from disease progression for overall survival of 82.5±6.9%. CONCLUSION: ETV6/RUNX1 (+) ALL may be heterogeneous in terms of prognosis, and variables such as MRD at end ofremission induction or additional structural abnormalities of 12p could define a subset of patients who are likely to have poor outcome.


Subject(s)
Cell Transplantation , Chromosome Aberrations , Diagnosis , Disease Progression , Disease-Free Survival , Fluorescence , Humans , In Situ Hybridization , Incidence , Korea , Multivariate Analysis , Neoplasm, Residual , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Prognosis , Recurrence , Remission Induction , Transplants
16.
Article in English | WPRIM | ID: wpr-8653

ABSTRACT

BACKGROUND: We describe the genetic profiles of Korean patients with glucose-6-phosphate dehydrogenase (G6PD) deficiencies and the effects of G6PD mutations on protein stability and enzyme activity on the basis of in silico analysis. METHODS: In parallel with a genetic analysis, the pathogenicity of G6PD mutations detected in Korean patients was predicted in silico. The simulated effects of G6PD mutations were compared to the WHO classes based on G6PD enzyme activity. Four previously reported mutations and three newly diagnosed patients with missense mutations were estimated. RESULTS: One novel mutation (p.Cys385Gly, labeled G6PD Kangnam) and two known mutations [p.Ile220Met (G6PD São Paulo) and p.Glu416Lys (G6PD Tokyo)] were identified in this study. G6PD mutations identified in Koreans were also found in Brazil (G6PD São Paulo), Poland (G6PD Seoul), United States of America (G6PD Riley), Mexico (G6PD Guadalajara), and Japan (G6PD Tokyo). Several mutations occurred at the same nucleotide, but resulted in different amino acid residue changes in different ethnic populations (p.Ile380 variant, G6PD Calvo Mackenna; p.Cys385 variants, Tomah, Madrid, Lynwood; p.Arg387 variant, Beverly Hills; p.Pro396 variant, Bari; and p.Pro396Ala in India). On the basis of the in silico analysis, Class I or II mutations were predicted to be highly deleterious, and the effects of one Class IV mutation were equivocal. CONCLUSIONS: The genetic profiles of Korean individuals with G6PD mutations indicated that the same mutations may have arisen by independent mutational events, and were not derived from shared ancestral mutations. The in silico analysis provided insight into the role of G6PD mutations in enzyme function and stability.


Subject(s)
Asian Continental Ancestry Group/genetics , Child , Child, Preschool , DNA/chemical synthesis , Exons , Glucosephosphate Dehydrogenase/chemistry , Glucosephosphate Dehydrogenase Deficiency/genetics , Humans , Male , Mutation, Missense , Polymorphism, Genetic , Protein Structure, Tertiary , Republic of Korea , Sequence Analysis, DNA
17.
Blood Research ; : 119-124, 2017.
Article in English | WPRIM | ID: wpr-62218

ABSTRACT

BACKGROUND: Autoimmune cytopenia (AIC) is a rare complication of allogeneic hematopoietic cell transplantation (HCT). In this study, we reviewed the diagnosis, treatment and response to therapy for pediatric patients with post-HCT AIC at our institution. METHODS: Of the 292 allogeneic HCTs performed from January, 2011 to December, 2015 at the Department of Pediatrics, The Catholic University of Korea, seven were complicated by post-HCT AIC, resulting in an incidence of 2.4%. RESULTS: All seven patients with post-HCT AIC had received unrelated donor transplant. Six of seven patients had a major donor-recipient blood type mismatch. The subtypes of AIC were as follows: immune thrombocytopenia (ITP) 2, autoimmune hemolytic anemia (AIHA) 2, Evans syndrome 3. Median time from HCT to AIC diagnosis was 3.6 months. All but one patient responded to first line therapy of steroid±intravenous immunoglobulin (IVIG), but none achieved complete response (CR) with this treatment. After a median duration of treatment of 15.3 months, two patients with ITP achieved CR and five had partial response (PR) of AIC. Five patients were treated with rituximab, resulting in the following response: 2 CR, 2 PR, 1 no response (NR). Median time to response to rituximab was 26 days from first infusion. All patients are alive without event. CONCLUSION: Post-HCT AIC is a rare complication that may not resolve despite prolonged therapy. Rapid initiation of second line agents including but not limited to B cell depleting treatment should be considered for those that fail to achieve CR with first line therapy.


Subject(s)
Anemia, Hemolytic, Autoimmune , Cell Transplantation , Child , Diagnosis , Humans , Immunoglobulins , Incidence , Korea , Pediatrics , Purpura, Thrombocytopenic, Idiopathic , Rituximab , Transplants , Unrelated Donors
18.
Article in English | WPRIM | ID: wpr-151579

ABSTRACT

We report the first Far Eastern case of a Korean child with familial hemophagocytic lymphohistiocytosis (HLH) caused by a novel syntaxin 11 (STX11) mutation. A 33-month-old boy born to non-consanguineous Korean parents was admitted for intermittent fever lasting one week, pancytopenia, hepatosplenomegaly, and HLH in the bone marrow. Under the impression of HLH, genetic study revealed a novel homozygous missense mutation of STX11: c.650T>C, p.Leu217Pro. Although no large deletion or allele drop was identified, genotype analysis demonstrated that the homozygous c.650T>C may have resulted from the duplication of a maternal (unimaternal) chromosomal region and concurrent loss of the other paternal allele, likely caused by meiotic errors such as two crossover events. A cumulative study of such novel mutations and their effects on specific protein interactions may deepen the understanding of how abnormal STX1 expression results in deficient cytotoxic function.


Subject(s)
Alleles , Amino Acid Sequence , Asian Continental Ancestry Group/genetics , Base Sequence , Bone Marrow/metabolism , Child, Preschool , Comparative Genomic Hybridization , DNA Mutational Analysis , Genotype , Haplotypes , Homozygote , Humans , Lymphohistiocytosis, Hemophagocytic/genetics , Male , Molecular Sequence Data , Mutation, Missense , Pedigree , Qa-SNARE Proteins/genetics , Republic of Korea , Sequence Alignment
19.
Infection and Chemotherapy ; : 181-189, 2016.
Article in English | WPRIM | ID: wpr-28872

ABSTRACT

BACKGROUND: The incidence of bacteremia caused by Gram-negative bacteria has increased recently in febrile neutropenic patients with the increase of antibiotic-resistant Gram-negative bacterial infections. This study aimed to identify the distribution of causative bacteria and the proportion of antibiotic-resistant bacteria in bacteremia diagnosed in febrile neutropenic children. MATERIALS AND METHODS: The medical records of febrile neutropenic children diagnosed with bacteremia between 2010 and 2014 were retrospectively reviewed. The causative bacteria and proportion of antibiotic-resistant bacteria were investigated and compared yearly during the study period. The clinical impact of antibiotic-resistant bacterial infections was also determined. RESULTS: A total of 336 bacteremia episodes were identified. During the entire study period, 181 (53.9%) and 155 (46.1%) episodes were caused by Gram-negative and Gram-positive bacteria, respectively. Viridans streptococci (25.9%), Klebsiella spp. (16.7%), and Escherichia coli (16.4%) were the most frequent causative bacteria. The overall distribution of causative bacteria was not significantly different annually. Antibiotic-resistant bacteria were identified in 85 (25.3%) episodes, and the proportion of antibiotic-resistant bacteria was not significantly different annually. Extended-spectrum β-lactamase-producing E. coli and Klebsiella spp. were most common among antibiotic-resistant Gram-negative bacteria, and they accounted for 30.6% (n = 34) of the identified E. coli and K. pneumoniae. Methicillin-resistant coagulase-negative staphylococci were most common among antibiotic-resistant Gram-positive bacteria, and it accounted for 88.5% (n = 23) of the identified coagulase-negative staphylococci. Antibiotic-resistant bacterial infections, especially antibiotic-resistant Gram-negative bacterial infections, caused significantly higher mortality due to bacteremia compared with non-antibiotic-resistant bacterial infections (P <0.001). CONCLUSION: Recently, Gram-negative bacteria caused more bacteremia cases than Gram-positive bacteria in febrile neutropenic children, and antibiotic-resistant Gram-negative bacterial infections increased. Antibiotic-resistant bacterial infections caused poorer prognosis compared with non-antibiotic-resistant bacterial infections, and therefore, continuous surveillance for changing epidemiology of antibiotic-resistant bacterial infections and their clinical impact is necessary.


Subject(s)
Bacteremia , Bacteria , Bacterial Infections , Child , Drug Resistance, Microbial , Epidemiology , Escherichia coli , Fever , Gram-Negative Bacteria , Gram-Negative Bacterial Infections , Gram-Positive Bacteria , Humans , Incidence , Klebsiella , Medical Records , Methicillin Resistance , Mortality , Neutropenia , Pneumonia , Prognosis , Retrospective Studies , Viridans Streptococci
20.
Blood Research ; : 249-255, 2016.
Article in English | WPRIM | ID: wpr-167171

ABSTRACT

BACKGROUND: Although intravenous acyclovir therapy is recommended for varicella zoster virus (VZV) infection in immunocompromised children, the clinical characteristics and outcomes of VZV infection in the acyclovir era have rarely been reported. METHODS: The medical records of children diagnosed with varicella or herpes zoster virus, who had underlying hematologic malignancies, were retrospectively reviewed, and the clinical characteristics and outcomes of VZV infection were evaluated. RESULTS: Seventy-six episodes of VZV infection (herpes zoster in 57 and varicella in 19) were identified in 73 children. The median age of children with VZV infection was 11 years (range, 1-17), and 35 (46.1%) episodes occurred in boys. Acute lymphoblastic leukemia was the most common underlying malignancy (57.9%), and 90.8% of the episodes occurred during complete remission of the underlying malignancy. Acyclovir was administered for a median of 10 days (range, 4-97). Severe VZV infection occurred in 16 (21.1%) episodes. Although the finding was not statistically significant, a previous history of hematopoietic cell transplantation (HCT) appeared to be associated with the development of more severe episodes of herpes zoster (P=0.075). CONCLUSION: Clinical characteristics of VZV infection in immunocompromised children were not significantly different from those without it, and clinical outcomes improved after the introduction of acyclovir therapy. However, risk factors for severe VZV infection require further investigation in a larger population and a prospective setting.


Subject(s)
Acyclovir , Cell Transplantation , Chickenpox , Child , Hematologic Neoplasms , Herpes Zoster , Herpesvirus 3, Human , Humans , Leukemia , Lymphoma , Medical Records , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Prospective Studies , Retrospective Studies , Risk Factors , Transplants
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