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1.  Clinical characteristics and outcomes of varicella zoster virus infection in children with hematologic malignancies in the acyclovir era 
Blood research  2016;51(4):249-255.
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.
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.
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).
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.
PMCID: PMC5234238  PMID: 28090487
Varicella zoster virus; Leukemia; Lymphoma; Child
2.  Increase in Antibiotic-Resistant Gram-Negative Bacterial Infections in Febrile Neutropenic Children 
Infection & Chemotherapy  2016;48(3):181-189.
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.
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).
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.
PMCID: PMC5047999  PMID: 27659431
Fever; Neutropenia; Bacteremia; Antibiotic resistance; Child
3.  Extramedullary Relapse of Acute Myeloid and Lymphoid Leukemia in Children: A Retrospective Analysis 
Iranian Journal of Pediatrics  2016;26(3):e1711.
Extramedullary relapse (EMR) is a recurrence of leukemia in sites other than the bone marrow, and it exhibits a relatively rare presentation of relapse of acute leukemia. However, EMR is an important cause of treatment failure among patients with acute leukemia. Therefore, early detection of these relapses may improve the prognosis.
To describe the disease-related demographic and clinical features and radiologic findings for children diagnosed with EMR in acute leukemia.
Patients and Methods
The study was based on 22 children (M: F = 14: 8; mean age 7.30 (2.1 - 15.7) years) with 8 acute myeloid leukemia (AML) and 14 acute lymphoid leukemia (ALL) who had experienced an EMR. Age, gender, clinical symptoms, initial extramedullary disease (EMD), French-American-British (FAB) morphology, cytogenetics, time to and site of EMR, concurrent bone marrow relapse (BMR), radiologic findings, and outcomes were evaluated.
No definite relationship was found between initial EMD and EMR. A predilection for AML to relapse in the central nervous system (CNS), except for the CSF and bone, and for ALL to relapse in the CSF and kidney seemed to occur. Patients with EMR had a significantly higher incidence of t(8: 21) cytogenetics and FAB M2 and L1 morphologies. EMR accompanied with concurrent BMR occurred in 31.8% of the patients, who exhibited a relatively grave clinical course. Radiologic findings were nonspecific and had a great variety of structure involved, including bulging enhancing mass in the CT scan, hypoechoic mass in the US, and enhanced mass-like lesion in the MRI.
Knowledge of the potential sites of EMR, their risk factors, and their clinical and radiologic features may be helpful in the early diagnosis of relapse and planning for therapy.
PMCID: PMC4992152  PMID: 27617062
Leukemia; Relapse; Extramedullary Leukemia; Pediatrics
4.  Subclinical left ventricular dysfunction in children after hematopoietic stem cell transplantation for severe aplastic anemia: a case control study using speckle tracking echocardiography 
Korean Journal of Pediatrics  2016;59(4):190-195.
Severe aplastic anemia (SAA), a fatal disease, requires multiple transfusion, immunosuppressive therapy, and finally, hematopoietic stem cell transplantation (HSCT) as the definitive treatment. We hypothesized that iron overloading associated with multiple transfusions and HSCTrelated complications may adversely affect cardiac function. Left ventricular (LV) function was assessed in children after HSCT for SAA.
Forty-six consecutive patients with a median age of 9.8 years (range, 1.5-18 years), who received HSCT for SAA and who underwent comprehensive echocardiography before and after HSCT, were included in this study. The data of LV functional parameters obtained using conventional echocardiography, tissue Doppler imaging (TDI), and speckle-tracking echocardiography (STE) were collected from pre- and post-HSCT echocardiography. These data were compared to those of 40 age-matched normal controls.
In patients, the LV ejection fraction, shortening fraction, end-diastolic dimension, mitral early diastolic E velocity, TDI mitral septal E' velocity, and STE LV longitudinal systolic strain rate (SSR) decreased significantly after HSCT. Compared to normal controls, patients had significantly lower post-HSCT early diastolic E velocity and E/A ratio. On STE, patients had significantly decreased LV deformational parameters including LV longitudinal systolic strain (SS), SSR, and diastolic SR (DSR), and circumferential SS and DSR. Serum ferritin levels showed weak but significant correlations (P<0.05) with LV longitudinal SS and SSR and circumferential SS and DSR.
Subclinical LV dysfunction is evident in patients after HSCT for SAA, and was associated with increased iron load. Serial monitoring of cardiac function is mandatory in this population.
PMCID: PMC4865643  PMID: 27186230
Aplastic anemia; Stem cell transplantation; Ventricular function; Speckle tracking echocardiography; Strain rate
5.  A Novel Syntaxin 11 Gene (STX11) Mutation c.650T>C, p.Leu217Pro, in a Korean Child With Familial Hemophagocytic Lymphohistiocytosis 
Annals of Laboratory Medicine  2015;36(2):170-173.
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.
PMCID: PMC4713852  PMID: 26709266
Syntaxin 11; Mutation; Hemophagocytic lymphohistiocytosis; Korean
6.  Cerebral salt-wasting syndrome after hematopoietic stem cell transplantation in adolescents: 3 case reports 
Cerebral salt-wasting syndrome (CSWS) is a rare disease characterized by a extracellular volume depletion and hyponatremia induced by marked natriuresis. It is mainly reported in patients who experience a central nervous system insult, such as cerebral hemorrhage or encephalitis. The syndrome of inappropriate antidiuretic hormone secretion is a main cause of severe hyponatremia after hematopoietic stem cell transplantation, whereas CSWS is rarely reported. We report 3 patients with childhood acute leukemia who developed CSWS with central nervous system complication after hematopoietic stem cell transplantation. The diagnosis of CSW was made on the basis of severe hyponatremia accompanied by increased urine output with clinical signs of dehydration. All patients showed elevated natriuretic peptide and normal antidiuretic hormone. Aggressive water and sodium replacement treatment was instituted in all 3 patients and 2 of them were effectively recovered, the other one was required to add fludrocortisone administration.
PMCID: PMC4722162  PMID: 26817009
Hyponatremia; Sodium; Polyuria; Hematopoietic stem cell transplantation
7.  Correlation of the clinical parameters with sonographic findings of hemorrhagic cystitis in pediatric hematooncology patients 
SpringerPlus  2015;4:577.
To find a relationship between clinical and sonographic appearance of hemorrhagic cystitis (HC) in pediatric hematooncology patients. Clinical and sonographic findings of 31 children (M:F = 18:13; mean age, 12.7 years) with HC in pediatric hematooncology patients were reviewed. For each patient, the onset of HC after transplantation, use of bladder-toxic agent, presence of BK viruria, and duration of disease were reviewed. Sonographic findings including bladder wall thickness (BWT), the type of bladder wall thickening (nodular vs. diffuse), occurrence of hydronephrosis or pyelonephritis were reviewed. We analyzed sonographic appearance and clinical manifestations of HC. HC occurred within 4 months after HSCT/BMT. 27 patients (87.0 %) were positive for BK viruria and 24 patients (77.4 %) took bladder-toxic agents. On sonography, nodular type bladder wall thickening was more frequent (54.8 %), and BWT was thicker in this group (p = 0.003). There was a positive correlation between the BWT on initial sonography and duration of cystitis (r2 = 0.340). Hydronephrosis developed in 25.8 % of patients with HC, and as HC persisted longer, hydronephrosis occurred more (p = 0.004). In patients with HC after HSCT/BMT, the BWT on initial sonography correlates well with the duration of cystitis. And, longer time of HC develops the risk of hydronephrosis.
PMCID: PMC4628028  PMID: 26543712
Cystitis; Sonography; Transplantation
8.  Hepatic veno-occlusive disease may develop in secondary iron overloaded mice after allogeneic hematopoietic stem cell transplantation with total body irradiation 
Blood research  2015;50(3):140-146.
The outcome of hematopoietic stem cell transplantation (HSCT) is poor in patients with secondary iron overload (SIO). We evaluated the relationship between SIO and veno-occlusive disease (VOD) in an animal model with radiation for HSCT.
We used a 6-week-old female BDF1 (H-2b/d) and a male C57/BL6 (H-2b) as recipient and donor, respectively. Recipient mice were injected intraperitoneally with 10 mg of iron dextran (cumulative doses of 50 mg, 100 mg, and 200 mg). All mice received total body irradiation for HSCT. We obtained peripheral blood for alanine transaminase (ALT) and liver for pathologic findings, lipid hyperoxide (LH) as reactive oxygen species (ROS), and liver iron content (LIC) on post-HSCT day 1 and day 7. The VOD score was assessed by pathologic findings.
ALT levels increased depending on cumulative iron dose, with significant differences between days 1 and 7 for mice loaded with 200 mg of iron (P<0.01). LH levels significantly increased in mice loaded with 200 mg of iron compared to those in other groups (P<0.01). For mice loaded with 100 mg of iron, the LH level depended on the radiation dose (P<0.01). There was a statistically significant relationship among ALT, LH, and LIC parameters (P<0.05). Pathologic scores for VOD correlated with LIC (P<0.01).
Livers with SIO showed high ROS levels depending on cumulative iron dose, and correlations with elevated liver enzyme and LIC. The pathologic score for VOD was associated with the LIC. Our results suggest that SIO may induce VOD after HSCT with irradiation.
PMCID: PMC4595579  PMID: 26457280
Iron overload; Hepatic veno-occlusive disease; Radiation; Reactive oxygen species
9.  Clinical Features and Prognosis of Invasive Pulmonary Aspergillosis in Korean Children with Hematologic/Oncologic Diseases 
Journal of Korean Medical Science  2015;30(8):1121-1128.
Invasive pulmonary aspergillosis (IPA) is the most frequent form of invasive fungal diseases in immunocompromised patients. However, there are only a few studies on IPA in immunocompromised children in Korea. This study was designed to characterize IPA in Korean children with hematologic/oncologic diseases. Medical records of children with hematologic/oncologic diseases receiving antifungal therapy were reviewed. The enrolled children were divided into the IPA group (proven and probable IPA) and non-IPA group, and the clinical characteristics and prognosis were compared between the two groups. During the study period, 265 courses of antifungal therapy were administered to 166 children. Among them, two (0.8%) episodes of proven IPA, 35 (13.2%) of probable IPA, and 52 (19.6%) of possible IPA were diagnosed. More children in the IPA group suffered from neutropenia lasting for more than two weeks (51.4% vs. 21.9%, P<0.001) and showed halo signs on the chest computed tomography (78.4% vs. 40.7%, P<0.001) than in the non-IPA group. No other clinical factors showed significant differences between the two groups. Amphotericin B deoxycholate was administered as a first line antifungal agent in 33 (89.2%) IPA group episodes, and eventually voriconazole was administered in 27 (73.0%) episodes. Ten (27.0%) children in the IPA group died within 12 weeks of antifungal therapy. In conclusion, early use of chest computed tomography to identify halo signs in immunocompromised children who are expected to have prolonged neutropenia can be helpful for early diagnosis of IPA and improving prognosis of children with IPA.
Graphical Abstract
PMCID: PMC4520943  PMID: 26240490
Invasive Pulmonary Aspergillosis; Immunocompromised Host; Child
10.  Serum galactomannan index for early prediction of mortality in immunocompromised children with invasive pulmonary aspergillosis 
BMC Infectious Diseases  2015;15:271.
Invasive pulmonary aspergillosis (IPA) is the most common invasive fungal disease in immunocompromised patients, and it has a 30 % mortality rate despite appropriate antifungal therapy. This retrospective study was performed to determine risk factors for mortality in immunocompromised children with IPA.
Medical records of 45 probable/proven IPA cases diagnosed in children with hematologic/oncologic diseases were reviewed. Selected cases were divided into the survival (n = 30) and fatality (n = 15) groups based on survival at 12 weeks after antifungal therapy. Clinical characteristics and serum galactomannan indices (GMIs) were compared between the two groups.
Significantly more children in the fatality group were male (p = 0.044), not in complete remission of the underlying malignancies (p = 0.016), and had received re-induction/salvage or palliative chemotherapy (p = 0.035) than those in the survival group. However, none of these factors was significantly associated with mortality in a multivariate analysis. Serum GMIs were higher in the fatality group than in the survival group during the entire period of antifungal therapy, and serum GMI at 1 week after antifungal therapy was most significantly associated with mortality. A serum GMI > 1.50 at 1 week after antifungal therapy exhibited a sensitivity and specificity of 61.5 % and 89.3 %, respectively, in predicting mortality within 12 weeks after antifungal therapy.
Higher serum GMI in the early phase of antifungal therapy was associated with mortality in immunocompromised children with IPA. These children should receive more intensive care for IPA than others.
PMCID: PMC4501281  PMID: 26168914
Invasive pulmonary aspergillosis; Galactomannan; Prognosis; Immunocompromised host; Child
13.  Neurocognitive Outcome in Survivors of Childhood Acute Lymphoblastic Leukemia: Experience at a Tertiary Care Hospital in Korea 
Journal of Korean Medical Science  2015;30(4):463-469.
This study was conducted to investigate long-term neurocognitive outcomes and to determine associated risk factors in a cohort of Korean survivors of childhood acute lymphoblastic leukemia (ALL). Forty-two survivors of ALL were compared with 42 healthy controls on measures of a neurocognitive test battery. We analysed potential risk factors (cranial irradiation, sex, age at diagnosis, elapsed time from diagnosis, and ALL risk group) on neurocognitive outcomes. ALL patients had lower, but non-significant full-scale intelligence quotient (FSIQ, 107.2±12.2 vs. 111.7±10.2), verbal intelligence quotient (VIQ, 107.7±13.6 vs. 112.2±11.4), and performance intelligence quotient (PIQ, 106.3±14.2 vs. 110.1±10.7) scores than healthy controls. However, patients treated with cranial irradiation performed significantly lower on FSIQ (102.2±8.1), VIQ (103.3±11.7), and PIQ (101.4±13.2) compared to non-irradiated patients and healthy controls. ALL patients also had poor attention, concentration, and executive functions. Among ALL survivors, cranial irradiation was a risk factor for poor FSIQ, being male was a risk factor for poor PIQ, and younger age was a risk factor for poor attention. Therefore, the delayed cognitive effects of ALL treatment and its impact on quality of life require continuing monitoring and management.
Graphical Abstract
PMCID: PMC4366968  PMID: 25829815
Acute Lymphoblastic Leukemia; Attention; Child; Cranial Irradiation; Cognition
14.  Anti-leukemic properties of deferasirox via apoptosis in murine leukemia cell lines 
Blood research  2015;50(1):33-39.
Although deferasirox (DFX) is reported to have anti-tumor effects, its anti-leukemic activity remains unclear. We evaluated the effect of DFX treatment on two murine lymphoid leukemia cell lines, and clarified the mechanisms underlying its potential anti-leukemic activity.
L1210 and A20 murine lymphoid leukemia cell lines were treated with DFX. Cell viability and apoptosis were evaluated by the 3-(4,5-dimethylthaizol-2-yl)-5-(3-carboxymethylphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and fluorescence-activated cell sorting (FACS) analysis, respectively. Immunoblotting was performed to detect the expression of key apoptotic proteins.
In dose- and time-dependent manner, DFX decreased viability and increased apoptosis of murine leukemic cells. Fas expression was significantly higher in A20 cells than in L1210 cells at all DFX concentrations tested. Although both cell lines exhibited high caspase 3 and caspase 9 expression, a critical component of the intrinsic mitochondrial apoptotic pathway, expression was greater in L1210 cells. In contrast, caspase 8, a key factor in the extrinsic apoptotic pathway, showed greater expression in A20 cells. Cytochrome c expression was significantly higher in L1210 cells. In both cell lines, co-treatment with ferric chloride and DFX diminished the expression of these intracellular proteins, as compared to DFX treatment alone.
Treatment with DFX increased caspase-dependent apoptosis in two murine lymphoid leukemia cell lines, with differing apoptotic mechanisms in each cell line.
PMCID: PMC4377336  PMID: 25830128
Lymphoid leukemia; Deferasirox; Apoptosis; Caspase
15.  Early Left Ventricular Dysfunction in Children after Hematopoietic Stem Cell Transplantation for Acute Leukemia: A Case Control Study Using Speckle Tracking Echocardiography 
Korean Circulation Journal  2015;45(1):51-58.
Background and Objectives
Cardiovascular complications are the leading cause of morbidity and mortality in childhood cancer survivors. Hematopoietic stem cell transplantation (HSCT) is a curable therapy for pediatric cancer. However, changes in cardiac function in children after HSCT are not well known. We assessed left ventricular (LV) function in children after HSCT using speckle tracking echocardiography (STE).
Subjects and Methods
Forty consecutive patients with median age of 11.9 years (range, 1.5-16 years) who received HSCT for acute leukemia and had comprehensive echocardiography before and after (median 9.2 month) HSCT were included in this study. The LV function parameters including conventional tissue Doppler imaging (TDI) and STE data were collected from pre- and post-HSCT echocardiography. These data were compared to those of 39 age-matched normal controls.
Compared to normal controls, post HSCT patients had similar (p=0.06) LV ejection fraction. However, the following three LV function parameters were significantly decreased in post HSCT patients: rate-corrected velocity of circumferential fiber shortening (p=0.04), mitral inflow E velocity (p<0.001), and mitral septal annular E' velocity (p=0.03). The following four STE parameters were also significantly decreased in post HSCT patients: LV global circumferential systolic strain (p<0.01), strain rate (SR, p=0.01), circumferential diastolic SR (p<0.01), and longitudinal diastolic SR (p<0.001). There was no significant change in TDI or STE parameters after HSCT compared to pre-HSCT. Patients with anthracycline cumulative dose >400 mg/m2 showed significantly (p<0.05) lower circumferential systolic strain and circumferential diastolic SR.
Subclinical cardiac dysfunction is evident in children after HSCT. It might be associated with pre-HSCT anthracycline exposure with little effect of conditioning regimens. Serial monitoring of cardiac function is mandatory for all children following HSCT.
PMCID: PMC4310980  PMID: 25653704
Childhood leukemia; Stem cell transplantation; Heart function; Speckle tracking; Echocardiography; Strain rate
16.  BK virus-associated hemorrhagic cystitis after pediatric stem cell transplantation 
Korean Journal of Pediatrics  2014;57(12):514-519.
Hemorrhagic cystitis is a common stem cell transplantation-related complication. The incidence of early-onset hemorrhagic cystitis, which is related to the pretransplant conditioning regimen, has decreased with the concomitant use of mesna and hyperhydration. However, late-onset hemorrhagic cystitis, which is usually caused by the BK virus, continues to develop. Although the BK virus is the most common pathogenic microorganism of poststem cell transplantation late-onset hemorrhagic cystitis, pediatricians outside the hemato-oncology and nephrology specialties tend to be unfamiliar with hemorrhagic cystitis and the BK virus. Moreover, no standard guidelines for the early diagnosis and treatment of BK virus-associated hemorrhagic cystitis after stem cell transplantation have been established. Here, we briefly introduce poststem cell transplantation BK virus-associated hemorrhagic cystitis.
PMCID: PMC4316594  PMID: 25653684
Cystitis; Stem cell transplantation; BK virus; Child
17.  Use of intravenous immunoglobulin in a disseminated varicella infection in an immunocompromised child 
Korean Journal of Pediatrics  2014;57(8):370-373.
Varicella-zoster virus infection can lead to severe illness in immunocompromised patients. Further the mortality rate of disseminated varicella infection is extremely high particularly in immunocompromised children. We report a case of disseminated varicella infection in a child with acute lymphoblastic leukemia who was receiving chemotherapy, but was initially admitted with only for acute abdominal pain. The patient rapidly developed severe complications, including acute respiratory distress syndrome, acute hepatitis, disseminated intravascular coagulation, and encephalopathy. Acyclovir is a highly potent inhibitor of varicella-zoster virus infection. However, owing to rapid disease progression, it might not be sufficient to control a disseminated varicella infection, especially in immunocompromised patients. Immunoglobulin neutralize virus invasion and suppress viremia, acting synergistically with acyclovir. In this case, early administration of acyclovir and a high-dose of immunoglobulin, combined with mechanical respiratory support, proved adequate for treatment of this severe illness.
PMCID: PMC4155182  PMID: 25210525
Varicella-zoster virus; Acyclovir; Immunoglobulin
18.  Novel Markers of Early Neutrophilic and Monocytic Engraftment after Hematopoietic Stem Cell Transplantation 
Annals of Laboratory Medicine  2014;34(2):92-97.
Numerous studies tried to find new markers that after hematopoietic stem cell transplantation predict engraftment earlier than the conventional marker, absolute neutrophil count (ANC >500/µL). Early engraftment prediction can be achieved by a marker that reflects the release of neutrophils and monocytes into the leukopenic peripheral blood.
We analyzed blood cell parameters, including cell population data such as volume, conductivity, and light scatter in 77 patients who underwent HSCT (allogeneic, n=63; autologous, n=11) to detect possible markers.
We identified 2 early engraftment markers of neutrophils (NEUTRO) and monocytes (MONO); a pair of mean-volume-neutrophils (MNV) and mean-conductivity-neutrophils (MNC) for NEUTRO; and a pair of mean-volume-monocytes (MMV) and mean-conductivity-monocytes (MMC) for MONO. The new markers showed distinct patterns for early engraftment wherein 1) on the engraftment day, MNV peaked as MNC notched simultaneously for every case, and 2) MMV peaked as MMC notched simultaneously in most cases. Engraftment was predicted 3.8±2.7 days earlier than by ANC in 74 successful engraftment cases by using NEUTRO and/or MONO: 1) 72 cases (97.3%), in which NEUTRO and/or MONO predicted earlier engraftment than ANC, 2) 1 case, in which the 3 markers predicted engraftment on the same day, and 3) 1 case, in which NEUTRO predicted engraftment on the same day as ANC and MONO failed to predict engraftment.
By analyzing the data from daily complete blood counts, engraftment can be predicted approximately 4 days earlier than ANC >500/µL using NEUTRO as a base marker and MONO as a supplementary marker.
PMCID: PMC3948839  PMID: 24624343
HSCT; Engraftment; Marker; Neutrophils; Monocytes
19.  Ribosomal protein mutations in Korean patients with Diamond-Blackfan anemia 
Diamond-Blackfan anemia (DBA) is a congenital bone marrow failure syndrome characterized by hypoproliferative anemia, associated physical malformations and a predisposition to cancer. DBA has been associated with mutations and deletions in the large and small ribosomal protein genes, and genetic aberrations have been detected in ∼50–60% of patients. In this study, nine Korean DBA patients were screened for mutations in eight known DBA genes (RPS19, RPS24, RPS17, RPS10, RPS26, RPL35A, RPL5 and RPL11) using the direct sequencing method. Mutations in RPS19, RPS26 and RPS17 were detected in four, two and one patient, respectively. Among the mutations detected in RPS19, two mutations were novel (c.26T>A, c.357-2A>G). For the mutation-negative cases, array-CGH analysis was performed to identify copy-number variations, and no deletions involving the known DBA gene regions were identified. The relative mRNA expression of RPS19 estimated using real-time quantitative PCR analysis revealed two- to fourfold reductions in RPS19 mRNA expression in three patients with RPS19 mutations, and p53 protein expression analysis by immunohistochemistry showed variable but significant nuclear staining in the DBA patients. In conclusion, heterozygous mutations in the known DBA genes RPS19, RPS26 and RPS17 were detected in seven out of nine Korean DBA patients. Among these patients, RPS19 was the most frequently mutated gene. In addition, decreased RPS19 mRNA expression and p53 overexpression were observed in the Korean DBA patients, which supports the hypothesis that haploinsufficiency and p53 hyperactivation represent a central pathway underlying the pathogenesis of DBA.
PMCID: PMC3972785  PMID: 24675553
array-CGH; Diamond-Blackfan anemia; ribosomal protein; sequencing
20.  Incidence and Risk Factors for Early-Onset Hypertension after Allogeneic Hematopoietic Stem Cell Transplantation in Children 
Korean Circulation Journal  2013;43(12):804-810.
Background and Objectives
Survivors of pediatric hematopoietic stem cell transplantation (HSCT) are at risk for developing hypertension. The objectives of this study are to evaluate the prevalence and risk factors of early onset hypertension during the engraftment period after HSCT.
Subjects and Methods
This is a retrospective study of 157 consecutive patients (mean age at HSCT: 9.1±5.1 years) who underwent HSCT for acute myeloid leukemia (n=47), acute lymphoblastic leukemia (n=43), severe aplastic anemia (n=41), and other reasons (n=26). Blood pressure data were collected at five time points: 0, 7, 14, 21, and 28 days after HSCT. Hypertension was defined as having systolic and/or diastolic blood pressure ≥95th percentile according to age, gender, and height. To analyze the risk factors related to hypertension, data, including patients' demographic and transplant characteristics, were reviewed.
Hypertension developed in 59 patients (38%), among whom 12 (7.6%) required long term therapy. Thirty-two (54%) patients had systolic and diastolic, 8 (14%) had only systolic, and 19 (32%) had only diastolic hypertension. Younger age, acute graft-versus-host disease, sinusoidal obstruction syndrome, treatment with antifungal agent, and greater increase in serum creatinine (Cr) levels were associated with hypertension. Multivariate analysis showed that younger age at HSCT and greater increase in serum Cr level were independent risk factors for hypertension.
Prevalence of hypertension during immediate post-HSCT period is high, especially in younger children. A greater increase in Cr after HSCT was significantly associated with hypertension. Further study is needed to elucidate long-term cardiovascular complications in pediatric HSCT survivors.
PMCID: PMC3875696  PMID: 24385991
Hematopoletic stem cell transplantation; Child; Incidence; Blood pressure; Hypertension
21.  Factors Related to Decreased Bone Mineral Density in Childhood Cancer Survivors 
Journal of Korean Medical Science  2013;28(11):1632-1638.
The risk of osteoporosis or osteopenia is known to increase after childhood cancer treatment. The purpose of this study was to evaluate patterns of bone mineral density (BMD) and to identify factors related to the decreased BMD in childhood cancer survivors. We studied 78 patients (34 boys, 44 girls) treated for childhood cancer. Twenty (25.7%) patients had lumbar BMD (LBMD) standard deviation score (SDS) lower than -2. Nineteen (24.4%) patients had femur neck BMD (FNBMD) SDS lower than -2. The patients treated with hematopoietic stem cell transplantation had lower LBMD SDS (-1.17 ± 1.39 vs -0.43 ± 1.33, P = 0.025). The risk of having LBMD SDS < -2 was higher in the patients treated with glucocorticoid (GC) for graft-versus-host disease (GVHD) (36.6% vs 13.5%; odds ratio [OR], 3.7; P = 0.020). In multivariate logistic regression analysis, longer duration of GC treatment for GVHD (OR, 1.12; 95% confidence interval [CI], 1.05-1.20) and lower body mass index (BMI) SDS (OR, 0.59; 95% CI, 0.36-0.95) were associated with decreased LBMD SDS. These findings suggest that prolonged GC use and reduction in BMI are risk factors for decreased BMD in childhood cancer survivors. Anticipatory follow-up and appropriate treatment are necessary, especially for the patients with risk factors.
PMCID: PMC3835506  PMID: 24265527
Bone Density; Neoplasms; Glucocorticoids
22.  Evaluation of risk for graft-versus-host disease in children who receive less than the full doses of mini-dose methotrexate for graft-versus-host disease prophylaxis in allogeneic hematopoietic stem cell transplantation 
Korean Journal of Pediatrics  2013;56(11):490-495.
The use of cyclosporine and mini-dose methotrexate (MTX) is a common strategy for graft-versus-host disease (GVHD) prophylaxis in allogeneic transplants. We investigated whether patients who receive fewer than the planned MTX doses are at increased risk for GVHD.
The study cohort included 103 patients who received allogeneic transplants at the Department of Pediatrics of The Catholic University of Korea College of Medicine, from January 2010 to December 2011. MTX was administered on days 1, 3, 6, and 11 after transplant at a dose of 5 mg/m2 each. Within the cohort, 76 patients (74%) received all 4 doses of MTX [MTX(4) group], while 27 patients (26%) received 0-3 doses [MTX(0-3) group].
Although there was no difference in neutrophil engraftment between the 2 groups, platelet engraftment was significantly faster in the MTX(4) group (median, 15 days), compared to the MTX(0-3) group (median, 25 days; P=0.034). The incidence of grades II-IV acute GVHD was not different between the MTX(4) and MTX(0-3) groups (P=0.417). In the multivariate study, human leukocyte antigen mismatch was the most significant factor causing grades II-IV acute GVHD (P=0.002), followed by female donor to male recipient transplant (P=0.034). No difference was found between the MTX(4) and MTX (0-3) groups regarding grades III-IV acute GVHD, chronic GVHD, and disease-free survival.
Our results indicate that deviations from the full dose schedule of MTX for GVHD prophylaxis do not lead to increased incidence of either acute or chronic GVHD.
PMCID: PMC3859882  PMID: 24348662
Methotrexate; Graft-versus-host disease; Prophylaxis
23.  Efficacy of imatinib mesylate-based front-line therapy in pediatric chronic myelogenous leukemia 
Korean Journal of Pediatrics  2013;56(8):343-350.
Despite the established role of imatinib (IM) in chronic myelogenous leukemia (CML) in adults, there are few reports on its efficacy in children. In this study, we compared the outcomes of children with CML before and after the advent of IM-based treatment.
The study cohort consisted of 52 patients treated for CML at the Department of Pediatrics, The Catholic University of Korea from January 1995 to October 2010. Patients were divided and analyzed according to the preImatinib group (pre-IMG) and imatinib group (IMG).
Median age at diagnosis for the overall cohort (pre-IMG, n=27; IMG, n=25) was 9 years, with a median follow-up duration of survivors of 84 months. Except for 5 patients in the IMG, all were diagnosed in chronic phase (CP). The overall survival (OS) of patients diagnosed in CP was 45.7% and 89.7% for pre-IMG and IMG, respectively (P=0.025). The OS of hematopoietic stem cell transplantation (HSCT) recipients in the 2 groups was similar, but the OS of patients diagnosed in CP who did not receive HSCT was superior in IMG (91.7% vs. 16.7%, P=0.014). Of the 12 patients in IMG who remained on IM without HSCT, 2 showed disease progression, compared to 11 of 12 in pre-IMG. No difference was observed in the progression free survival (PFS) of matched donor HSCT recipients and IM-based treatment recipients.
Similar PFS of patients treated with IM and those who received matched donor HSCT underscore the potential of IM as effective first-line treatment in childhood CML.
PMCID: PMC3764259  PMID: 24019845
Chronic myelogenous leukemia; Imatinib mesylate; Allogeneic transplantation; Children
24.  Risk factors for short term thyroid dysfunction after hematopoietic stem cell transplantation in children 
Korean Journal of Pediatrics  2013;56(7):298-303.
The purpose of this study was to evaluate short-term thyroid dysfunction and related risk factors in pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) during childhood.
We studied 166 patients (100 boys and 66 girls) who underwent HSCT at the Catholic HSCT Center from January 2004 through December 2009. The mean age at HSCT was 10.0±4.8 years. Thyroid function of the patients was tested before and during 3 months of HSCT.
Out of 166 patients, 165 (99.4%) underwent allotransplantation. Acute graft-versus-host disease (GVHD, grades II to IV) developed in 76 patients. Conditioning regimens before HSCT include total body irradiation (n=57), busulfan (n=80), and reduced intensity (n=29). Forty-five (27.1%) had thyroid dysfunction during 3 months after HSCT (29 euthyroid sick syndrome [ESS], 6 subclinical hyperthyroidism, 4 subclinical hypothyroidism, 3 hypothyroxinemia, 2 overt hyperthyroidism, and 1 high T4 syndrome). In a univariate logistic regression analysis, age at HSCT (P=0.002) and acute GVHD (P=0.009) had statistically significant relationships with thyroid dysfunction during 3 months after HSCT. Also, in a univariate logistic regression analysis, ESS (P=0.014) showed a strong statistically significant association with mortality.
In our study 27.1% patients experienced thyroid dysfunction during 3 months after HSCT. Increase in age and acute GVHD may be risk factors for thyroid dysfunction during 3 months after HSCT. There was a significant association between ESS and mortality.
PMCID: PMC3728449  PMID: 23908670
Hematopoietic stem cell transplantation; Thyroid dysfunction; Child; Graft-vs-host disease; Euthyroid sick syndrome
25.  Clinical characteristics and antimicrobial susceptibilities of viridans streptococcal bacteremia during febrile neutropenia in patients with hematologic malignancies: a comparison between adults and children 
BMC Infectious Diseases  2013;13:273.
This study was performed to compare the clinical characteristics and antibiotic susceptibilities of viridans streptococcal bacteremia (VSB) between febrile neutropenic adults and children with hematologic malignancies.
The consecutive medical records of neutropenic patients with hematologic malignancies who were admitted to the Catholic Blood and Marrow Transplantation Center between April 2009 and July 2012, and who were subsequently diagnosed with VSB were reviewed retrospectively. A comparison was made between the clinical and laboratory characteristics of adults and pediatric patients and also between patients with cefepime susceptible or not susceptible VSB.
A total of 202 episodes (141 in adults, 61 in children) of VSB were identified. Among them, 26 (12.9%) cases had severe complications including four (2.0%) cases of death attributable to VSB. For antibacterial prophylaxis, most adults received ciprofloxacin (97.1%), but children more frequently received trimethoprim/sulfamethoxazole (86.9%). Oral mucositis (p = 0.005) and abdominal pain (p = 0.001) were found more frequently in adults, and cough was found more frequently in children (p = 0.004). The occurrence rates of severe complications and death attributable to VSB were not significantly different between adults and children. Susceptibility rate to cefepime was significantly higher in adults than children (85.7% vs. 66.1%, p = 0.002). However, in multivariate analysis, cefepime susceptibility had no impact on clinical outcome.
There was no significant difference in clinical outcome between adults and children with VSB despite a difference in cefepime susceptibility. Hence, different antibiotic treatment strategies may not be necessary.
PMCID: PMC3685537  PMID: 23773209
Viridans streptococci; Bacteremia; Neutropenia; Fever

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