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1.  Clinical characteristics and treatment outcomes of children with anaplastic large cell lymphoma: a single center experience 
Blood research  2014;49(4):246-252.
Anaplastic large cell lymphoma (ALCL) is uncommon in children, accounting for approximately 15% of all cases of childhood non-Hodgkin lymphoma. Despite many studies attempting new treatment strategies, treatment outcomes have not significantly improved, and the optimal treatment for pediatric ALCL has not been established.
The records of newly diagnosed ALCL patients at our institute between July 1998 and April 2013 were reviewed. We evaluated the general characteristics of the patients, chemotherapy regimens, overall survival (OS) rates, and event-free survival (EFS) rates.
Twenty-eight ALCL patients were eligible. The median age at diagnosis was 10.8 years. Lymph node involvement was the most common presentation (79%). CCG-5941, a multi-agent T-cell lineage chemotherapy, was the predominant treatment regimen (57%). The five-year OS and EFS rates were 88% and 69%, respectively. Stage, the presence of B symptoms, lung involvement, and bone marrow involvement were significant prognostic factors for EFS (P=0.02, 0.01, 0.01, and 0.02, respectively). Eight patients relapsed, and three died during the study period. Four of the eight patients who relapsed were treated with high-dose chemotherapy and autologous stem cell transplantation (HDCT-ASCT). Two of the four who had undergone HDCT-ASCT developed secondary relapses and were subsequently treated with allogeneic SCT or brentuximab.
We found that treatment outcomes with multi-agent chemotherapy in children with ALCL were similar to those of previous reports, and that relapsed patients could be salvaged with HDCT-ASCT or allogeneic SCT. A prospective, larger cohort study is warranted to define the optimal treatment for pediatric ALCL.
PMCID: PMC4278006  PMID: 25548758
Anaplastic large cell lymphoma; Childhood; Prognosis; Relpase
2.  Chronic Epstein-Barr virus infection causing both benign and malignant lymphoproliferative disorders 
Korean Journal of Pediatrics  2014;57(9):420-424.
The Epstein-Barr virus (EBV) is oncogenic and can transform B cells from a benign to a malignant phenotype. EBV infection is also associated with lymphoid interstitial pneumonia (LIP). Here, we report the case of a 14-year-old boy who was diagnosed with a latent EBV infection and underlying LIP, without any associated immunodeficiency. He had been EBV-seropositive for 8 years. The first clinical presentations were chronic respiratory symptoms and recurrent pneumonia. The symptoms worsened in the following 2 years. The results of in situ hybridization were positive for EBV, which led to a diagnosis of LIP. The diagnosis was confirmed by the results of a thoracoscopic lung biopsy. The EBV titer of the bronchoalveolar lavage specimens obtained after acyclovir treatment was found to be fluctuating. The patient had latent EBV infection for 8 years, until presented at the hospital with intermittent abdominal pain and distension. Physical examination and pelvic computed tomography revealed a large mesenteric mass. A biopsy of the excised mass led to a diagnosis of Burkitt's lymphoma (BL). The patient received combination chemotherapy for 4 months, consisting of vincristine, methotrexate, cyclophosphamide, doxorubicin, and prednisolone. He is now tumor-free, with the LIP under control, and is being followed-up at the outpatient clinic. This is the first report of a Korean case of chronic latent EBV infection that developed into LIP and BL in a nonimmunocompromised child.
PMCID: PMC4198958  PMID: 25324869
EBV infection; Lymphoid interstitial pneumonia; Burkitt's lymphoma
3.  Clinical Significance of Previously Cryptic Copy Number Alterations and Loss of Heterozygosity in Pediatric Acute Myeloid Leukemia and Myelodysplastic Syndrome Determined Using Combined Array Comparative Genomic Hybridization plus Single-Nucleotide Polymorphism Microarray Analyses 
Journal of Korean Medical Science  2014;29(7):926-933.
The combined array comparative genomic hybridization plus single-nucleotide polymorphism microarray (CGH+SNP microarray) platform can simultaneously detect copy number alterations (CNA) and copy-neutral loss of heterozygosity (LOH). Eighteen children with acute myeloid leukemia (AML) (n=15) or myelodysplastic syndrome (MDS) (n=3) were studied using CGH+SNP microarray to evaluate the clinical significance of submicroscopic chromosomal aberrations. CGH+SNP microarray revealed CNAs at 14 regions in 9 patients, while metaphase cytogenetic (MC) analysis detected CNAs in 11 regions in 8 patients. Using CGH+SNP microarray, LOHs>10 Mb involving terminal regions or the whole chromosome were detected in 3 of 18 patients (17%). CGH+SNP microarray revealed cryptic LOHs with or without CNAs in 3 of 5 patients with normal karyotypes. CGH+SNP microarray detected additional cryptic CNAs (n=2) and LOHs (n=5) in 6 of 13 patients with abnormal MC. In total, 9 patients demonstrated additional aberrations, including CNAs (n=3) and/or LOHs (n=8). Three of 15 patients with AML and terminal LOH>10 Mb demonstrated a significantly inferior relapse-free survival rate (P=0.041). This study demonstrates that CGH+SNP microarray can simultaneously detect previously cryptic CNAs and LOH, which may demonstrate prognostic implications.
Graphical Abstract
PMCID: PMC4101780  PMID: 25045224
Leukemia, Myeloid, Acute; DNA Copy Number Variations; Loss of Heterozygosity; Comparative Genomic Hybridization; Single-Nucleotide Polymorphism Microarray
4.  Effect of Human Parathyroid Hormone on Hematopoietic Progenitor Cells in NOD/SCID Mice Co-Transplanted with Human Cord Blood Mononuclear Cells and Mesenchymal Stem Cells 
Yonsei Medical Journal  2012;54(1):238-245.
We evaluated the effect of human parathyroid hormone (hPTH) on the engraftment and/or in vivo expansion of hematopoietic stem cells in an umbilical cord blood (UCB)-xenotransplantation model. In addition, we assessed its effect on the expression of cell adhesion molecules.
Materials and Methods
Female NOD/SCID mice received sublethal total body irradiation with a single dose of 250 cGy. Eighteen to 24 hours after irradiation, 1×107 human UCB-derived mononuclear cells (MNCs) and 5×106 human UCB-derived mesenchymal stem cells (MSCs) were infused via the tail vein. Mice were randomly divided into three groups: Group 1 mice received MNCs only, Group 2 received MNCs only and were then treated with hPTH, Group 3 mice received MNCs and MSCs, and were treated with hPTH.
Engraftment was achieved in all the mice. Bone marrow cellularity was approximately 20% in Group 1, but 70-80% in the hPTH treated groups. Transplantation of MNCs together with MSCs had no additional effect on bone marrow cellularity. However, the proportion of human CD13 and CD33 myeloid progenitor cells was higher in Group 3, while the proportion of human CD34 did not differ significantly between the three groups. The proportion of CXCR4 cells in Group 3 was larger than in Groups 1 and 2 but without statistical significance.
We have demonstrated a positive effect of hPTH on stem cell proliferation and a possible synergistic effect of MSCs and hPTH on the proportion of human hematopoietic progenitor cells, in a xenotransplantation model. Clinical trials of the use of hPTH after stem cell transplantation should be considered.
PMCID: PMC3521258  PMID: 23225826
Umbilical cord blood; parathyroid hormone; bone marrow niches
5.  Central nervous system (CNS) involvement is a critical prognostic factor for hemophagocytic lymphohistiocytosis 
The Korean Journal of Hematology  2012;47(4):273-280.
Hemophagocytic lymphohistiocytosis (HLH) is a rare multisystem disorder that frequently involves the central nervous system (CNS). We compared the clinical characteristics, treatment, and prognosis of patients with HLH according to the degree of CNS involvement.
The clinical manifestations, initial laboratory data, treatment, and outcomes for 50 patients diagnosed with HLH and treated at Asan Medical Center between January 1995 and August 2011 were retrospectively reviewed and analyzed. CNS involvement was defined as the presence of neurological symptoms or an elevated white blood cell (WBC) count in the cerebrospinal fluid (CSF).
Among these 50 patients, 23 (46%) developed CNS disease. Among patients with CNS disease, 19 had neurological symptoms, including seizures, altered consciousness, facial palsy, dysarthria, and dysphagia. Four patients had elevated CSF WBC counts without neurological symptoms. Twelve patients had abnormal brain imaging results, including high signal intensity lesions on T2-weighted magnetic resonance imaging (MRI) findings, ventriculomegaly, hemorrhage, atrophy, and leptomeningeal enhancement. Patients with CNS disease had lower ferritin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels as well as reduced 5-year survival as compared to those without CNS disease.
CNS involvement is common among patients with HLH. Overall, patients with CNS disease achieve poorer outcomes than patients without CNS involvement. To improve outcomes, physicians must carefully monitor the neurological manifestations in patients with HLH and administer the appropriate course of intensified chemotherapy to patients with CNS disease.
PMCID: PMC3538799  PMID: 23320006
Hemophagocytic lymphohistiocytosis; Central nervous system involvement; Neurological manifestations; Cerebrospinal fluid; Outcome
6.  Role of HLA in Hematopoietic Stem Cell Transplantation 
Bone Marrow Research  2012;2012:680841.
The selection of hematopoietic stem cell transplantation (HSCT) donors includes a rigorous assessment of the availability and human leukocyte antigen (HLA) match status of donors. HLA plays a critical role in HSCT, but its involvement in HSCT is constantly in flux because of changing technologies and variations in clinical transplantation results. The increased availability of HSCT through the use of HLA-mismatched related and unrelated donors is feasible with a more complete understanding of permissible HLA mismatches and the role of killer-cell immunoglobulin-like receptor (KIR) genes in HSCT. The influence of nongenetic factors on the tolerability of HLA mismatching has recently become evident, demonstrating a need for the integration of both genetic and nongenetic variables in donor selection.
PMCID: PMC3467756  PMID: 23082252
7.  Factors influencing lymphocyte reconstitution after allogeneic hematopoietic stem cell transplantation in children 
Immune reconstitution (IR) after hematopoietic stem cell transplantation (HSCT) reduces transplantation-related complications such as infection and improves HSCT outcomes.
We retrospectively analyzed IR of lymphocyte subpopulations in 38 pediatric patients for hematologic malignant diseases after allogeneic HSCT from April 2006 to July 2008. T-cell-, B-cell-, and natural killer (NK) cell-associated antigens were assayed in peripheral blood by flow cytometry analysis of 5 lymphocyte subsets, CD3+, CD3+/CD4+, CD4+/CD8+, CD16+/CD56+, and CD19+, before and 3 and 12 months after transplantation.
Reconstitutions of CD16+/CD56+ and CD3+/CD8+ lymphocytes were achieved rapidly, whereas that of CD3+/CD19+ lymphocytes occurred later. Age was not related to reconstitution of any lymphocyte subset. Total body irradiation (TBI) and anti-thymocyte globulin (ATG) administration were related to delayed reconstitution of total lymphocytes and CD3+ lymphocytes, respectively. Reconstitutions of CD3+/CD4+ lymphocytes and CD3+/CD8+ lymphocytes were significantly delayed in patients who received umbilical cord blood stem cells. In patients with chronic graft-versus-host disease (cGVHD), recovery of the total lymphocyte count and CD19+ lymphocytes at 3 months post-transplant were significantly delayed. However, acute GVHD (aGVHD) and cytomegalovirus (CMV) reactivation did not influence the IR of any lymphocyte subset. Further, delayed reconstitution of lymphocyte subsets did not correspond to inferior survival outcomes in this study.
We observed that some lymphocyte reconstitutions after HSCT were influenced by the stem cell source and preparative regimens. However, delayed CD19+ lymphocyte reconstitution may be associated with cGVHD.
PMCID: PMC3317470  PMID: 22479277
Immune reconstitution; Hematopoietic stem cell transplantation; Children; Lymphocyte subset
8.  New clinical score for disease activity at diagnosis in Langerhans cell histiocytosis 
The Korean Journal of Hematology  2011;46(3):186-191.
The clinical presentation and course of Langerhans cell histiocytosis (LCH) are variable, ranging from an isolated, spontaneously remitting bone lesion to multisystem disease with risk organ involvement. Treatment of LCH ranges from a wait-and-see attitude to intensive multidrug therapy and, in some cases, bone marrow transplantation. It is necessary to develop an objective score for assessing disease activity in patients with LCH. We propose a new clinical scoring system to evaluate disease activity at diagnosis that can predict the clinical outcomes of LCH and correlate it with clinical courses.
Clinical data, obtained from children diagnosed with LCH at Asan Medical Center and Hanyang University Hospital between March 1998 and February 2009, were studied retrospectively. The scoring system was developed according to the basic biological data, radiological findings, and physical findings and applied to a database containing information on 133 patients.
The median age of the 133 patients (74 male, 59 female) was 52 months (range, 0.6-178 months), and LCH was diagnosed based on CD1a positivity. At diagnosis, the score distributions were highly asymmetrical: the score was between 1 and 2 in 75.9% of cases, 3-6 in 15.8%, and greater than 6 in 8.3%. Initial scores above 6 were highly predictive of reactivation and late complications.
This new LCH disease activity score provides an objective tool for assessing disease severity, both at diagnosis and during follow-up.
PMCID: PMC3208202  PMID: 22065974
Histiocytosis; Langerhans cells; Disease activity; Clinical score
9.  Lineage Switch at Relapse of Childhood Acute Leukemia: A Report of Four Cases 
Journal of Korean Medical Science  2011;26(6):829-831.
Lineage switch in acute leukemia is an uncommon event at relapse, and therefore rarely reported in the literature. Here, we have described the clinical laboratory features of four cases in which the cell lineage switched from acute lymphoblastic leukemia (ALL) to acute myeloid leukemia (AML). One patient was initially diagnosed with B-ALL, switched to T-ALL at the first relapse, and eventually, AML at the second relapse. A lineage switch represented either relapse of the original clone with heterogeneity at the morphologic level or emergence of a new leukemic clone. Further sequential phenotypic and cytogenetic studies may yield valuable insights into the mechanisms of leukemic recurrence, with possible implications for treatment selection.
PMCID: PMC3102880  PMID: 21655072
Lineage Switch; Acute Leukemia
10.  The impact of HLA matching on unrelated donor hematopoietic stem cell transplantation in Korean children 
The impact of HLA matching on outcomes of unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) varies in different racial or ethnic groups. Since little is known about the impact of such matching on URD HSCT in Korean children, we analyzed this issue.
We analyzed the outcomes of 142 patients who underwent URD HSCT at 4 Korean medical centers. All patient donor pairs were fully typed for HLA-A, -B, -C, and -DR alleles.
At a median follow-up of 22 months, 3-year survival rates for patients with 8, 7, and ≤6 matched alleles were 88.4%, 70.7%, and 53.6%, respectively. A single mismatch (Mm) at HLA-B or -C was associated with lower survival compared with that associated with 8 matched alleles. No significant differences were observed between single-allele and single-antigen Mms with respect to survival rate or acute graft-versus-host disease (aGVHD) incidence rates. HLA disparity had a greater impact on the survival of patients with high-risk malignancy than of those with low-risk malignancy. Among pairs with a single Mm, only locus A showed a significant association and higher risk of grade III-IV aGVHD compared to those in patients with 8 matched alleles.
Disparity in HLA class I, regardless of antigen or allele Mm, adversely affected both survival and grade III-IV aGVHD development. An increased number of HLA Mms was associated with a higher risk of post-transplantation complications. Further investigations using larger cohorts are required to confirm the effects of HLA mismatching on URD HSCT patient outcomes.
PMCID: PMC3065620  PMID: 21461298
URD HSCT; HLA; Korean children
11.  Role of p16 in the pathogenesis of Langerhans cell histiocytosis 
The Korean Journal of Hematology  2010;45(4):247-252.
It has been hypothesized that genetic alteration at the cellular level may have a significant effect on cellular mechanisms controlling the proliferation and apoptosis of Langerhans cells (LCs).
We examined whether p16 protein expression can be used to predict the outcome of Langerhans cell histiocytosis (LCH). Archival paraffin blocks from children diagnosed with LCH and followed at the Asan Medical Center and Chungnam National University Hospital between March 1998 and February 2008 were studied.
Slides were stained with p16 antibody and evaluated semi-quantitatively using the following scale: negative, no staining; ±, weakly positive; 1+, staining similar to lymphocytes surrounding the LCs; 2+, stronger staining than lymphocytes; 3+, much stronger staining than lymphocytes. Negative and ± groups were assigned to a lower expression group (LEG) and the 1+, 2+, and 3+ groups were assigned to a higher expression group (HEG). The median age of the 51 patients (24 girls, 27 boys) was 49 (range, 0.6-178) months, and LCH was diagnosed based on CD1a positivity. p16 protein was expressed to varying degrees in all but one specimen. There was a greater tendency toward multisystem disease, risk organ involvement, and relapse in the HEG than in the LEG.
The p16 protein may have a significant effect on cellular mechanisms controlling the proliferation and apoptosis of LCs, and thus may influence the clinical outcome and prognosis of LCH.
PMCID: PMC3023050  PMID: 21253426
Genes; p16; Histiocytosis; Langerhans cells; Immunohistochemistry
12.  Prognostic significance of minimal residual disease detected by a simplified flow cytometric assay during remission induction chemotherapy in children with acute lymphoblastic leukemia 
Korean Journal of Pediatrics  2010;53(11):957-964.
Our study attempted to determine the prognostic significance of minimal residual disease (MRD) detected by a simplified flow cytometric assay during induction chemotherapy in children with B-cell acute lymphoblastic leukemia (B-ALL).
A total of 98 patients were newly diagnosed with precursor B-ALL from June 2004 to December 2008 at the Asan Medical Center (Seoul, Korea). Of those, 37 were eligible for flow cytometric MRD study analysis on day 14 of their induction treatment. The flow cytometric MRD assay was based on the expression intensity of CD19/CD10/CD34 or aberrant expression of myeloid antigens by bone marrow nucleated cells.
Thirty-five patients (94.6%) had CD19-positive leukemic cells that also expressed CD10 and/or CD34, and 18 (48.6%) had leukemic cells with aberrant expression of myeloid antigens. Seven patients with ≥1% leukemic cells on day 14 had a significantly lower relapse-free survival (RFS) compared to the 30 patients with lower levels (42.9% [18.7%] vs. 92.0% [5.4%], P=0.004). Stratification into 3 MRD groups (≥1%, 0.1-1%, and <0.1%) also showed a statistically significant difference in RFS (42.9% [18.7%] vs. 86.9% [8.7%] vs. 100%, P=0.013). However, the MRD status had no significant influence on overall survival. Multivariate analysis demonstrated that the MRD level on day 14 was an independent prognostic factor with borderline significance.
An MRD assay using simplified flow cytometry during induction chemotherapy may help to identify patients with B-ALL who have an excellent outcome and patients who are at higher risk for relapse.
PMCID: PMC3012276  PMID: 21218018
Lymphoblastic leukemia; Acute; Childhood; Minimal residual disease; Flow cytometry
13.  Improved outcome in childhood ALL with intensive consolidation and hematopoietic stem cell transplant 
The Korean Journal of Hematology  2010;45(2):109-114.
Despite advances in chemotherapy, the prognosis of relapsed acute lymphoblastic leukemia (ALL) remains poor. Few studies on relapsed ALL have reported the importance of intensive consolidation followed with or without allogeneic hematopoietic stem cell transplantation (HSCT).
We evaluated the post-relapse outcomes in 47 Korean children with a first marrow relapse, and analyzed the prognostic factors.
A second complete remission (CR) was achieved in 40 patients (85.1%), and at the time of this study, second CR was maintained in 12 of these patients. The estimated 3-yr event-free survival (EFS) rate after the first marrow relapse was 29.8±6.7%, and the overall survival (OS) rate was 45.3±7.5%. We found that second remission, consolidation of pediatric oncology group chemotherapy regimen (POG 9411), and HSCT significantly affected the outcome of the disease after relapse (P<0.001; P=0.004; P=0.05).
The results of our study revealed that an intensified POG 9411 consolidation chemotherapy regimen followed by HSCT can improve the outcome of patients with relapsed ALL.
PMCID: PMC2983016  PMID: 21120189
Acute lymphoblastic leukemia; Relapse; Intensive consolidation; Hematopoietic stem cell transplantation
14.  A case of anemia caused by combined vitamin B12 and iron deficiency manifesting as short stature and delayed puberty 
Korean Journal of Pediatrics  2010;53(5):661-665.
Anemia caused by vitamin B12 deficiency resulting from inadequate dietary intake is rare in children in the modern era because of improvements in nutritional status. However, such anemia can be caused by decreased ingestion or impaired absorption and/or utilization of vitamin B12. We report the case of an 18-year-old man with short stature, prepubertal sexual maturation, exertional dyspnea, and severe anemia with a hemoglobin level of 3.3 g/dL. He had a history of small bowel resection from 50 cm below the Treitz ligament to 5 cm above the ileocecal valve necessitated by midgut volvulus in the neonatal period. Laboratory tests showed deficiencies of both vitamin B12 and iron. A bone marrow examination revealed dyserythropoiesis and low levels of hemosiderin particles, and a cytogenetic study disclosed a normal karyotype. After treatment with parenteral vitamin B12 and elemental iron, both anemia and growth showed gradual improvement. This is a rare case that presented with short stature and delayed puberty caused by nutritional deficiency anemia in Korea.
PMCID: PMC2994119  PMID: 21189935
Vitamin B12 and iron deficiency anemia; Short bowel syndrome; Short stature; Delayed puberty
15.  CD34 and p53 Immunohistochemical Stains Differentiate Hypocellular Myelodysplastic Syndrome (hMDS) from Aplastic Anemia and a CD34 Immunohistochemical Stain Provides Useful Survival Information for hMDS 
Annals of Laboratory Medicine  2014;34(6):426-432.
The presence of significant dysplasia in bone marrow (BM) aspirates helps to distinguish between hypocellular myelodysplastic syndrome (hMDS) and aplastic anemia (AA). Occasionally, diluted BM aspirates make it difficult to recognize dysplastic changes and can also negatively affect the detection of cytogenetic abnormalities in hMDS. We evaluated the usefulness of CD34 and p53 immunoreactivity for discriminating between hMDS and AA and for estimating survival outcomes in hMDS patients.
BM clot section (BMC) or BM biopsy (BMB) specimens were obtained from 64 hMDS/AA patients (33 with hMDS and 31 with AA) and seven controls. Immunohistochemical (IHC) staining for CD34 and p53 was performed by using the EnVision detection system (Dako, Denmark). We compared the results of IHC staining, BM findings, and chromosomal analyses, and determined overall survival outcomes.
The number of CD34- and p53-positive BM cells was higher among the patients with hMDS than among the patients with AA (P<0.001 and P=0.001, respectively). hMDS patients with increased CD34-positive cells had significantly poorer survival outcomes compared with those with normal number of CD34-positive cells (P=0.013).
CD34 and p53 IHC stains of BMC or BMB provide useful information for differentiating between hMDS and AA. CD34 IHC staining of BMC or BMB also provides useful information for estimating survival outcomes in hMDS patients.
PMCID: PMC4215417  PMID: 25368817
Hypocellular myelodysplastic syndrome; Aplastic anemia; Immunohistochemistry; CD34; p53
16.  Presence of Differentiating Neuroblasts in Bone Marrow is a Favorable Prognostic Factor for Bone Marrow Metastatic Neuroblastoma at Diagnosis 
Annals of Laboratory Medicine  2013;33(2):89-96.
The prognostic impact of the presence of differentiating neuroblasts in bone marrow (BM) remains unclear in BM metastatic neuroblastoma (NB). We aimed to identify the prognostic impact of differentiating neuroblasts in BM at diagnosis and after chemotherapy.
A total of 51 patients diagnosed with BM metastatic NB at Asan Medical Center between January 1990 and July 2005 were enrolled. BM histology and laboratory data along with overall survival (OS) were compared with regard to the differentiation status of neuroblasts in BM at diagnosis and after chemotherapy.
Among the 51 patients, 13 (25.5%) exhibited differentiating neuroblasts in BM at diagnosis and 17/51 (33.3%) exhibited them after chemotherapy. The only significant difference among patient groups was the improved OS in patients with differentiated neuroblasts in BM at diagnosis (P=0.021). In contrast, the differentiation status of neuroblasts in BM after chemotherapy did not affect OS (P=0.852).
Our study is the first report describing the presence of differentiating neuroblasts in BM. The presence of differentiating neuroblasts in BM at diagnosis may be a favorable prognostic factor for patients with BM metastatic NB; however, the same phenomenon after chemotherapy is irrelevant to prognosis.
PMCID: PMC3589646  PMID: 23483759
Differentiating neuroblasts; Neuroblastoma; Bone marrow; Metastasis; Prognosis
17.  Prognostic significance of gelsolin and MMP12 in Langerhans cell histiocytosis 
The Korean Journal of Hematology  2012;47(4):267-272.
Gelsolin and matrix metalloproteinase 12 (MMP12) expression has been reported in Langerhans cell histiocytosis (LCH), but the clinical significance of this expression is unknown. We investigated the associations of these proteins with clinical manifestations in patients diagnosed with LCH.
We performed a retrospective analysis of clinical data from patients diagnosed with LCH and followed up between 1998 and 2008. Available formalin-fixed, paraffin-embedded specimens were used for gelsolin and MMP12 immunohistochemical staining. We analyzed the expression levels of these proteins and their associations with LCH clinical features.
Specimens from 36 patients (20 males, 16 females) with a diagnosis of LCH based on CD1a positivity with clinical manifestations were available for immunohistochemical staining. Median patient age was 62 months (range, 5 to 207). The expression of gelsolin varied; it was high in 17 patients (47.2%), low in 11 patients (30.6%), and absent in 8 patients (22.2%). The high gelsolin expression group had a higher tendency for multi-organ and risk organ involvement, although the trend was not statistically significant. MMP12 was detected only in 7 patients (19.4%) who showed multi-system involvement (P=0.018) and lower event-free survival (P=0.002) in comparison to patients with negative MMP12 staining.
Gelsolin and MMP12 expression may be associated with the clinical course of LCH, and MMP12 expression may be particularly associated with severe LCH. Further studies of larger populations are needed to define the precise role and significance of gelsolin and MMP12 in the pathogenesis of LCH.
PMCID: PMC3538798  PMID: 23320005
Histiocytosis; Langerhans cells; Immunohistochemistry; Gelsolin; Matrix Metalloproteinase 12
18.  Clinical and hematologic manifestations in patients with Diamond Blackfan anemia in Korea 
The Korean Journal of Hematology  2012;47(2):131-135.
Diamond Blackfan anemia (DBA), characterized by impaired red cell production, is a rare condition that is usually symptomatic in early infancy. The purpose of this study was to assess nationwide experiences of DBA encountered over a period of 20 years.
The medical records of 56 patients diagnosed with DBA were retrospectively reviewed from November 1984 to July 2010. Fifteen institutions, including 13 university hospitals, participated in this study.
The male-to-female ratio of patients with DBA was 1.67:1. The median age of diagnosis was 4 months, and 74.1% were diagnosed before 1 year of age. From 2000 to 2009, annual incidence was 6.6 cases per million. Excluding growth retardation, 38.2% showed congenital defects: thumb deformities, ptosis, coarctation of aorta, ventricular septal defect, strabismus, etc. The mean hemoglobin concentration was 5.1±1.9 g/dL, mean corpuscular volume was 93.4±11.6 fL, and mean number of reticulocytes was 19,700/mm3. The mean cellularity of bone marrow was 75%, with myeloid:erythroid ratio of 20.4:1. After remission, 48.9% of patients did not need further steroids. Five patients with DBA who received hematopoietic transplantation have survived. Cancer developed in 2 cases (3.6%).
The incidence of DBA is similar to data already published, but our study had a male predilection. Although all patients responded to initial treatment with steroids, about half needed further steroids after remission. It is necessary to collect further data, including information regarding management pathways, from nationwide DBA registries, along with data on molecular analyses.
PMCID: PMC3389062  PMID: 22783360
Diamond Blackfan anemia; Anemia; Congenital defects
19.  Clinical implications of chimerism after allogeneic hematopoietic stem cell transplantation in children with non-malignant diseases 
The Korean Journal of Hematology  2011;46(4):258-264.
The effects of chimerism on outcomes following allogeneic hematopoietic stem cell transplantation (HSCT) are unclear and may differ between diseases. We retrospectively evaluated the association between chimerism and transplant outcomes in children with nonmalignant diseases.
Chimerism was evaluated using short-tandem repeat polymerase chain reaction (STR-PCR) in 48 patients, with mixed chimerism (MC) defined as greater than 1% recipient cells.
The only variable exerting a significant influence on patients' chimerism status was the number of infused CD34+ cells. MC was detected in 23 transplants (9 showing transient MC; 10 with sustained low levels [≤30%] of autologous cells; and 4 with high-level MC [>30%]). The degree of STR-PCR at 28 days after HSCT was significantly higher in patients with high-level MC than those with transient or low-level MC. All patients with transient or low-level MC successfully maintained engraftment and showed a clinical response to HSCT, whereas 2 of the 4 patients with high-level MC experienced graft failure. The incidences of grades II-IV acute and chronic graft-versus-host disease (GVHD) were significantly higher in patients with complete donor chimerism (CC) than MC. We observed no significant survival differences between CC and MC groups. However, the survival rate was lower in patients with high MC than those with low-level or transient MC (P=0.03).
In non-malignant diseases, MC may indicate a tolerant state with a decreased incidence of GVHD. However, high-level MC may signify an increased risk of graft failure and a lower survival rate.
PMCID: PMC3259518  PMID: 22259632
Non-malignant disease; Allogeneic hematopoietic stem cell transplantation; Chimerism
20.  Prognostic significance of the FLT3 ITD mutation in patients with normal-karyotype acute myeloid leukemia in relapse 
Fms-like tyrosine kinase 3 internal tandem duplication (FLT3 ITD) mutation is related to poor prognosis in normal-karyotype acute myeloid leukemia (AML). However, the prognostic significance of the mutation at relapse has not been adequately investigated. We investigated the prognostic significance of the FLT3 ITD mutation at relapse in normal-karyotype AML patients.
We analyzed 69 normal-karyotype AML patients, in whom paired bone marrow samples taken at initial diagnosis and subsequent relapse were analyzed for the FLT3 ITD mutation at the Asan Medical Center between 1995 and 2009.
Forty patients showed a persistent wild-type genotype, 11 showed the FLT3 ITD mutation at diagnosis and relapse, and 9 lost and another 9 acquired the mutation at relapse. The mutation status at relapse affected the overall survival (OS), with the mutation group showing shorter OS and survival after relapse than the wild-type group did (P<0.001 and P<0.001, respectively), despite having received more frequent stem cell transplantation after relapse than the wild-type group did. However, no difference was detected in the OS and survival after relapse with regard to the mutation status at diagnosis.
The patients with FLT3 ITD mutation at relapse showed poorer prognoses than those without the mutation. However, mutation status at diagnosis did not affect the outcome. These results suggest that, in normal-karyotype AML patients with relapse, the prognostic significance of FLT3 ITD mutation at relapse is greater than that of the mutation status at diagnosis.
PMCID: PMC3128906  PMID: 21747880
AML; Prognosis; FLT3 ITD; Relapse; Normal karyotype
21.  Clinical features of infantile hepatic hemangioendothelioma 
Korean Journal of Pediatrics  2011;54(6):260-266.
Infantile hepatic hemangioendothelioma (IHHE) is the most common type of hepatic vascular tumor in infancy. We conducted this study to review our clinical experience of patients with IHHE and to suggest management strategies.
We retrospectively analyzed the medical records of 23 IHHE patients (10 males, 13 females) treated at the Asan Medical Center between 1996 and 2009.
Median age at diagnosis was 38 days (range, 1 to 381 days). Seven patients (30%) were diagnosed with IHHE based on sonographically detected fetal liver masses, 5 (22%) were diagnosed incidentally in the absence of symptoms, 5 (22%) had congestive heart failure, 3 (13%) had skin hemangiomas, 2 (9%) had abnormal liver function tests, and 1 (4%) had hepatomegaly. All diagnoses were based on imaging results, and were confirmed in three patients by histopathology analysis. Six patients were observed without receiving any treatment, whereas 12 received corticosteroids and/or interferon-alpha. One patient with congestive heart failure and a resectable unilobar tumor underwent surgical resection. Three patients with congestive heart failure and unresectable tumors were managed by hepatic artery embolization with/without medical treatment. At a median follow-up of 29 months (range, 1 to 156 months), 21 (91%) patients showed complete tumor disappearance or >50% decrease in tumor size. One patient died due to tumor-related causes.
IHHE generally has a benign clinical course with low morbidity and mortality rates. Clinical course and treatment outcome did not differ significantly between medically treated and non-treated groups. Surgically unresectable patients with significant symptoms may be treated medically or with hepatic artery embolization.
PMCID: PMC3174362  PMID: 21949521
Infant; Liver; Hemangioendothelioma; Corticosteroid; Interferon-alpha; Therapeutic embolization
22.  Acute Promyelocytic Leukemia Presenting with Central Nervous System Involvement: A Report of 2 Cases 
Central nervous system (CNS) involvement in acute promyelocytic leukemia (APL) is rare, and the presence of CNS symptoms at the time of diagnosis of APL is even rarer. We report 2 cases of APL presenting with CNS involvement. A 43-yr-old woman presented with easy bruising and stuporous mentality. Her complete blood count (CBC) revealed leukocytosis with increased blasts. Bone marrow (BM) analysis was carried out, and the diagnosis of APL was confirmed. This was done by cytogenetic analysis and demonstration of PML-RARα rearrangement by reverse transcriptase PCR in the BM cells. A lumbar puncture was performed to investigate the cause of her stuporous mentality, and her cerebrospinal fluid (CSF) analysis revealed 97% leukemic promyelocytes. Despite systemic and CNS therapy, she died due to septic shock by infection and rapid disease progression only 3 days after her admission. Another patient, a 3-yr-old girl, presented with easy bruising and epistaxis, and her CBC showed pancytopenia with increased blasts. BM studies confirmed APL. Quantitative PCR for PML-RARα in the BM cells revealed a PML-RARα/ABL ratio of 0.33 and CSF analysis revealed 9.5% leukemic promyelocytes (2 of 21 cells). She received induction chemotherapy and intrathecal therapy and achieved complete remission (CR) in the BM and CNS. She has been maintained in the CR status for the past 31 months. Thus, patients with APL must be evaluated for CNS involvement if any neurological symptoms are present at the time of diagnosis.
PMCID: PMC3111037  PMID: 21239864
Acute promyelocytic leukemia; Central nervous system involvement; Disease presentation
23.  Polymorphisms in innate immunity genes and risk of childhood leukemia 
Human immunology  2010;71(7):727-730.
To evaluate whether candidate genes in innate immunity are associated with childhood leukemia, we conducted an association study with the 1,536 SNPs in 203 genes related to innate immunity.
Incident childhood leukemia cases (n=136) aged from 0 to 18 were recruited from three teaching hospitals in Seoul between 2003 and 2006. Non-cancer controls (n=140) were frequency-matched to cases by age and gender. The information on the characteristics of children and their parents were collected by trained interviewers using structured questionnaire. Candidate genes were selected based on SNP databases (CGAP and SNP500 database), and genotype assay was performed using GoldenGate (Illumina) oligonucleotide pool assay (OPA). False discovery rate (FDR), permutation test, and haplotype analyses were used to identify the SNP with significant association with childhood leukemia. Childhood leukemia risk was estimated as ORs and 95% CIs adjusted for age, gender and birth weight.
Fourteen SNPs in 13 genes (LMAN1, TLR4, STAT4, CCR9, MBP, ZP1, C8B, XDH, C7, C1QG, FGF2, LOC390183, and STAT6) were significantly associated with childhood leukemia risk (FDR p-values <0.05). In particular, LMAN1 rs1127220, TLR4 rs11536897, STAT4 rs13020076, CCR9 rs1471962, and MBP rs10514234 were significant in 5,000 permutation tests (Permutation p-value <0.05). The most significant association with childhood leukemia risk was for the LMAN1 rs1127220 that is in the protein-coding region, this finding was also supported by haplotype analysis.
A number of innate immunity related genes are associated with childhood leukemia, suggesting possible links between the innate immunity system and development of the childhood leukemia.
PMCID: PMC2967770  PMID: 20438785
Childhood Leukemia; Innate Immunity; Single Nucleotide Polymorphism
24.  Early central nervous system complications after allogeneic hematopoietic stem cell transplantation in children 
The Korean Journal of Hematology  2010;45(3):164-170.
Central nervous system (CNS) complications after allogeneic hematopoietic stem cell transplantation (HSCT) have not been well characterized in the pediatric population.
We retrospectively analyzed data of 202 consecutive children who underwent allogeneic HSCT (60 from matched related donors, 9 from mismatched related donors, and 133 from unrelated donors) at Asan Medical Center between 1998 and 2009.
Twenty-seven children (13.5%) developed CNS complications within 6 months after HSCT. Calcineurin inhibitor (CNI)-associated neurotoxicity was the most common CNS complication (n=16), followed by CNS infection (n=2), cerebrovascular events (n=2), thrombotic microangiopathy-associated events (n=2), metabolic encephalopathy (n=2), irradiation/chemotherapy injury (n=1), and encephalopathy/myelopathy of unknown causes (n=2). Univariate analysis showed that a transplant from an alternative donor and the occurrence of acute graft-versus-host disease (GVHD) (>grade 2) were associated with a significantly increased risk of CNS complications. In the multivariate analysis, acute GVHD >grade 2 was identified as an independent risk factor for early CNS complications. The 5-year overall survival rate was significantly lower in patients with CNS complications (52.1% vs. 64.9%, P=0.014), whereas CNI-associated neurotoxicity did not affect the survival outcome.
CNS complications are frequent among children undergoing HSCT, contributing to early death after transplant. More attention should be paid to the development of CNS complications for recipients of alternative donor transplants and patients with severe acute GVHD who are at increased risk for CNS complications.
PMCID: PMC2983044  PMID: 21120204
Allogeneic; Hematopoietic stem cell transplantation; Neurological complication; Cyclosporine; Children
25.  Efficacy of High-dose Chemotherapy and Autologous Stem Cell Transplantation in Patients with Relapsed Medulloblastoma: A Report on The Korean Society for Pediatric Neuro-Oncology (KSPNO)-S-053 Study 
Journal of Korean Medical Science  2010;25(8):1160-1166.
The efficacy and toxicity of high-dose chemotherapy and autologous stem cell transplantation (HDCT/ASCT) were investigated for improving the outcomes of patients with relapsed medulloblastoma. A total of 15 patients with relapsed medulloblastoma were enrolled in the KSPNO-S-053 study from May 2005 to May 2007. All patients received approximately 4 cycles of salvage chemotherapy after relapse. Thirteen underwent HDCT/ASCT; CTE and CM regimen were employed for the first HDCT (HDCT1) and second HDCT (HDCT2), respectively, and 7 underwent HDCT2. One transplant related mortality (TRM) due to veno-occlusive disease (VOD) occurred during HDCT1 but HDCT2 was tolerable with no further TRM. The 3-yr overall survival probability and event-free survival rates ±95% confidence intervals (CI) were 33.3±12.2% and 26.7% ±11.4%, respectively. When analysis was confined to only patients who had a complete response (CR) or partial response (PR) prior to HDCT, the probability of 3-yr overall survival rates ±95% CI was 40.0±15.5%. No patients with stable disease (SD) or progressive disease (PD) survived. Survival rates from protocol KSPNO-S-053 are encouraging and show that tumor status prior to HDCT/ASCT is an important factor to consider for improving survival rates of patients with relapsed medulloblastoma.
PMCID: PMC2908784  PMID: 20676326
Recurrence; Medulloblastoma; Transplantation, Autologous; Tandem; Hematopoietic Stem Cell Transplantation

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