PURPOSE: This study was aimed to investigate the clinical and epidemiological characteristics of the patients with acute bronchiolitis who visited in 146 Emergency Departments (EDs) in Korea in 2012. METHODS: We used the NEDIS (National Emergency Department Information System) database to obtain all children with acute bronchiolitis who visited ED under the age of 3 between January 1, 2012 and December 31, 2012. RESULTS: Totally 18,313 children with acute bronchiolitis were enrolled at this study. The male to female ratio was 1.55:1 and mean age was 10 months. The peak proportion was 17.3% in November during the whole year. The most common chief complaints were fever (38.5%), cough (37.4%), dyspnea (9.5%), gastrointestinal symptom (6.7%), and wheezing (2.5%). The most common accompanying disease was pneumonia (13.3%). The rate of hospital admission and intensive care unit admission were 34.5% and 0.3%, respectively. A predictor for admission via ED was respiratory difficulty. CONCLUSION: These data expand our understanding of clinical characteristics of patients with acute bronchiolitis who visited all ED in Korea in 2012.
Bronchiolitis* ; Child ; Cough ; Dyspnea ; Emergencies* ; Emergency Service, Hospital* ; Female ; Fever ; Humans ; Intensive Care Units ; Korea* ; Male ; Pneumonia ; Respiratory Sounds

Cord blood is one of the promising sources of hematopoietic stem cell and the public cord blood bank should cryopreserve only high quality, conforming cord blood units for transplantation. Cryopreserved cord blood units have several advantages over other hematopoietic stem cell sources such as bone marrow or mobilized peripheral stem cells; cord blood is in the ready-to-use state after the necessary testing and cause less graft-versus-host disease due to cellular immaturity. The limiting factor is the restricted cell number, which resulted in delayed engraftment and immunologic reconstitution. Selection of cord blood for patients is determined by two criteria: the number of total nucleated cell and the matching of human leukocyte antigen. The cord blood inventory required for any given ethnicity is determined by HLA diversity. In terms of growing interest of cord blood as a stem cell source, we reviewed the current status of cord blood related issues in Korea.
Bone Marrow ; Cell Count ; Fetal Blood ; Fibrinogen ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; Humans ; Korea ; Leukocytes ; Stem Cells ; Transplants

BACKGROUND: Mycoplasma spp. occasionally colonize the genital tract and these organisms are some of the most important contaminants in cell culture laboratories and cell banks. We analyzed the Mycoplasma contamination rates in the donated cord blood units (CBUs) before cell processing. METHODS: A total of 151 CBUs that were donated with informed consent (November 3rd~December 28th, 2006) were randomly selected and enrolled in the study. We performed blood culture and Mycoplasma DNA PCR assay with using samples from the collection bags before processing. RESULTS: All of the CBUs were obtained from full-term (gestational age 37~42 weeks) deliveries. Two units showed positive results on blood culture however, Mycoplasma DNA is not found in the tested samples. CONCLUSION: The contamination rates of Mycoplasma in the CBUs, which are donated from the mothers who have full-term delivery and no pregnancy complications, are extremely low. The donated CBUs could be used in culture and for an expansion process without concern of incurring pre-processing Mycoplasma contamination. The rate of Mollicute contamination in the CBUs could become clear with the results of performing Ureaplasma assay.
Cell Culture Techniques ; Colon ; DNA ; Fetal Blood ; Humans ; Informed Consent ; Mothers ; Mycoplasma ; Polymerase Chain Reaction ; Pregnancy Complications ; Ureaplasma

Intermediate-resolution HLA-DQ typing has gained importance in organ transplantation recently. We evaluated the performance of the LIFECODES HLA-DQB1 typing kit (Immucor, USA) using sequence-specific oligonucleotide (SSO) probe and Luminex platform (Luminex Corp., USA) on 100 samples tested by sequence-based typing (SBT) using the AlleleSEQR HLA-DQB1 kit (Abbott Molecular, USA) in Korean individuals. No sample showed ambiguity in the assignment of 4-digit HLA-DQB1 allele with the LIFECODES HLA-DQB1 SSO typing kit, and the results were fully concordant with those of high-resolution typing of AlleleSEQR HLA-DQB1 SBT up to 4-digit level. Three samples required adjustment of false reactions (3/100, 3.0%): two samples with DQB1*03:03/*06:01 showed false-positive result in probe 253, and 1 sample with DQB1*04:02/*05:02 showed false-negative result in probe 217. We tested an additional sample with DQB1*03:03/*06:01, which showed same false-positivity in probe 253 and 2 samples with DQB1*04:02/*05:02, which showed no false reaction. The false reactions did not result in ambiguity or change in the HLA allele assignment. We could assign HLA-DQB1 alleles to 4 digit-level without ambiguity, with 100% concordance with the SBT results. Thus, LIFECODES HLA-DQB1 SSO typing kit showed good performance for intermediate-resolution HLA-DQB1 typing in clinical laboratory for organ transplantation in Koreans.
Alleles ; DNA Primers/metabolism ; Gene Frequency ; Genotype ; HLA-DQ beta-Chains/*genetics/metabolism ; Histocompatibility Testing/*standards ; Humans ; Polymerase Chain Reaction ; Reagent Kits, Diagnostic/*standards ; Republic of Korea

BACKGROUND: Flow cytometric crossmatching (FCXM) is widely used in hospitals performing solid organ transplantation. Pronase treatment of lymphocytes can increase the sensitivity and specificity of B-cell FCXM. However, it can also affect human leukocyte antigen (HLA) expression and results of FCXM. We treated lymphocytes with various concentrations of pronase and analysed the effect of the treatment on the FCXM results. METHODS: The peripheral blood mononuclear cells isolated from 10 renal transplant donors were treated with three different concentrations of pronase (0.5, 1.0, and 2.0 mg/mL). The effects of pronase on median fluorescence intensity (MFI) values of AB serum (Fcγ receptor), HLA class I and II, and on the MFI ratio of HLA class I and II were analysed. RESULTS: In B-cell FCXM, the MFI values of AB serum (Fcγ receptor) and HLA class I were significantly decreased by the pronase treatment. The MFI ratio of HLA class II was significantly increased upon treatment with 0.5, 1.0, and 2.0 mg/mL pronase (P<0.05, P<0.01, and P<0.01, respectively). In T-cell FCXM, the MFI ratio of HLA class I was significantly decreased by the pronase treatment (all P<0.01). CONCLUSIONS: When performing FCXM, it is recommended that B-lymphocytes should be treated with 1.0 or 2.0 mg/mL pronase. In the case of T-lymphocytes, pronase treatment should be adopted with caution.
B-Lymphocytes ; Flow Cytometry ; Fluorescence ; Humans ; Leukocytes ; Lymphocytes ; Organ Transplantation ; Pronase* ; Sensitivity and Specificity ; T-Lymphocytes ; Tissue Donors ; Transplants

BACKGROUND: Data on allele frequencies (AFs) and haplotype frequencies (HFs) of HLA-C and -DQB1 are limited in Koreans. We investigated AFs and HFs of HLA-A, -B, -C, -DRB1, and -DQB1 in Koreans by high-resolution sequence-based typing (SBT). METHODS: Hematopoietic stem cells were obtained from 613 healthy, unrelated donors to analyze HLA-A, -B, -C, -DRB1, and -DQB1 genotypes by using AlleleSEQR HLA-A, -B, -C, -DRB1, and -DQB1 SBT kits (Abbott Molecular, USA), respectively. Alleles belonging to HLA-C*07:01/07:06 group were further discriminated by using PCR-sequence specific primer analysis. AFs and HFs were calculated by direct counting and maximum likelihood method, respectively. RESULTS: In all, 24 HLA-A, 46 HLA-B, 24 HLA-C, 29 HLA-DRB1, and 15 HLA-DQB1 alleles were identified. AFs and HFs of HLA-A, -B, and -DRB1 were similar to those reported previously. For the HLA-C locus, C*01:02 was the most common allele, followed by C*03:03, C*03:04, C*14:02, C*03:02, and C*07:02 (AF > or =7%). AFs of C*07:01 and C*07:06 were 0.16% and 3.18%, respectively. For the HLA-DQB1 locus, DQB1*03:01 was the most common allele, followed by DQB1*03:03, *03:02, *06:01, *05:01, *04:01, and *06:02 (AF > or =7%). AFs of DQB1*02:01 and DQB1*02:02 were 2.12% and 6.69%, respectively. HFs of A*33:03-C*07:06 and C*07:06-B*44:03 were 3.09% and 3.10%, respectively, while those of DRB1*07:01-DQB1*02:02 and DRB1*03:01-DQB1*02:01 were 6.61% and 2.04%, respectively. CONCLUSIONS: This study reported AFs and HFs of HLA, including HLA-C and -DQB1, in Koreans by using high-resolution SBT. These data can be used to resolve ambiguous results of HLA typing for organ and hematopoietic stem cell transplantations.
Alleles* ; DNA Fingerprinting* ; Gene Frequency ; Genotype ; Haplotypes* ; Hematopoietic Stem Cells ; Histocompatibility Testing ; HLA Antigens ; HLA-A Antigens ; HLA-B Antigens ; HLA-C Antigens ; HLA-DRB1 Chains ; Humans ; Korea ; Leukocytes* ; Sequence Analysis ; Unrelated Donors

BACKGROUND: Although cord blood (CB) is a well-known source of hematopoietic stem cells, uncertainties exist regarding the quality of cryopreserved CB. We investigated the changes in quality of CB units according to the duration of cryopreservation. METHODS: We analyzed CB units that were rejected from the Seoul Metropolitan Government Public Cord Blood Bank inventory after conventional processing, because of unsuitability for allogeneic transplantation. Two hundred CB units that were cryopreserved from 1 year to 5 years were selected. After thawing the cryopreserved CB units, the total nucleated cell (TNC) count, CD34+ cell count, number of colony-forming units (CFU), aldehyde dehydrogenase (ALDH) level, cell viability, and apoptosis were analyzed. We conducted a comparative analysis to identify the presence of statistically significant differences in the recovery rates of the TNC and CD34+ cell counts and to compare the results of ALDH level, the cell viability test, the apoptosis test, and CFU analysis among groups according to the duration of cryopreservation. RESULTS: The recovery rates of the TNC count, the CD34+ cell count, and cell viability did not differ significantly according to the duration of cryopreservation. ALDH analysis, the cell viability test, and the apoptosis test did not reveal any increasing or decreasing trend according to the duration of cryopreservation. Further, the numbers of CFU-granulocyte/macrophage and CFU-granulocyte/erythrocyte/macrophage/megakaryocyte did not differ significantly according to the duration of cryopreservation. CONCLUSION: These results suggest that the quality of CB is not affected by cryopreservation for up to a period of 5 years.
Aldehyde Dehydrogenase ; Apoptosis ; Cell Count ; Cell Survival ; Cryopreservation ; Fetal Blood* ; Hematopoietic Stem Cells ; Local Government ; Seoul ; Stem Cells ; Transplantation, Homologous

Background: Several T-cell response assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are available; however, their comparability and correlations with antibody responses remain unclear. We compared four SARS-CoV-2 T-cell response assays and two anti-SARS-CoV-2 spike antibody assays. Methods: We enrolled 89 participants who had received a booster dose of the BNT162b2 vaccine after two doses of the ChAdOx1 or BNT162b2 vaccine. Fifty-six participants without breakthrough infection (BI) (ChAdOx1/BNT162b2 group: N=27; BNT162b2 group: N=29) and 33 with BI were included. We evaluated two whole-blood interferon-gamma release assays (IGRAs) (QuantiFERON and Euroimmun), T-SPOT.COVID, an in-house enzyme-linked immunospot (ELISPOT) assay (targeting the spike and nucleocapsid peptides of wild-type and Omicron SARS-CoV-2), Abbott IgG II Quant, and Elecsys Anti-S, using Mann–Whitney U, Wilcoxon signed-rank, and Spearman’s correlation tests. Results: The correlations between the IGRAs and between the ELISPOT assays (ρ=0.60–0.70) were stronger than those between the IGRAs and ELISPOT assays (ρ=0.33–0.57). T-SPOT.COVID showed a strong correlation with Omicron ELISPOT (ρ=0.70). The anti-spike antibody assays showed moderate correlations with T-SPOT.COVID, Euroimmun IGRA, and ELISPOT (ρ=0.43–0.62). Correlations tended to be higher in the BI than in the noninfected group, indicating that infection induces a stronger immune response. Conclusions T-cell response assays show moderate to strong correlations, particularly when using the same platform. T-SPOT.COVID exhibits potential for estimating immune responses to the Omicron variant. To accurately define SARS-CoV-2 immune status, both T-cell and B-cell response measurements are necessary.

BACKGROUND: Reference intervals need to be established according to age. We established reference intervals of hematology and chemistry from community-based healthy 1-yr-old children and analyzed their iron status according to the feeding methods during the first six months after birth. METHODS: A total of 887 children who received a medical check-up between 2010 and 2014 at Boramae Hospital (Seoul, Korea) were enrolled. A total of 534 children (247 boys and 287 girls) were enrolled as reference individuals after the exclusion of data obtained from children with suspected iron deficiency. Hematology and clinical chemistry analytes were measured, and the reference value of each analyte was estimated by using parametric (mean±2 SD) or nonparametric methods (2.5-97.5th percentile). Iron, total iron-binding capacity, and ferritin were measured, and transferrin saturation was calculated. RESULTS: As there were no differences in the mean values between boys and girls, we established the reference intervals for 1-yr-old children regardless of sex. The analysis of serum iron status according to feeding methods during the first six months revealed higher iron, ferritin, and transferrin saturation levels in children exclusively or mainly fed formula than in children exclusively or mainly fed breast milk. CONCLUSIONS: We established reference intervals of hematology and clinical chemistry analytes from community-based healthy children at one year of age. These reference intervals will be useful for interpreting results of medical check-ups at one year of age.
Breast Feeding ; Clinical Chemistry Tests/*standards ; Female ; Hematologic Tests/*standards ; Humans ; Infant ; Iron/*blood/standards ; Male ; Reference Values ; Republic of Korea

PURPOSE: Acute respiratory infection, particularly pneumonia, is the most common cause of hospitalization and death among children in developing nations. This study aimed to investigate the characteristics of children and adolescents with pneumonia who visited Emergency Department (ED) in South Korea in 2012. METHODS: We analyzed National Emergency Department Information System (NEDIS) records from 146 EDs in South Korea for all pediatric patients aged ≤18 years who were diagnosed with pneumonia between January and December 2012. RESULTS: Among 38,415 subjects, the male-to-female ratio was 1:0.8. Patients aged <12 months comprised 18.0% of the study population; those aged 1 to 3 years, 54.4%; those aged 4 to 6 years, 16.8%; those aged 7 to 12 years, 7.4%; and those aged 13 to 18 years, 3.4%. Presentation rates were highest in April, followed by January, March, and May. The hospital admission rate was 43.5%, of which 2.6% were in intensive care units. The mortality rate was 0.02%. Based on the International Classification of Diseases, 10th Revision, diagnostic codes, the types of pneumonia according to cause were viral pneumonia (29.0%), bacterial pneumonia (5.3%), Mycoplasmal pneumonia (4.5%), aspiration pneumonia (1.3%), and pneumonia of unknown origin (59.3%). CONCLUSION: Despite the limited data due to the ED data from the NEDIS lacking laboratory results and treatment information, this study reflects well the outbreak patterns among children and adolescents with pneumonia. Our results provide a basis for future studies regarding ED treatment for children and adolescents with pneumonia.
Adolescent* ; Child* ; Developing Countries ; Emergencies* ; Emergency Service, Hospital* ; Hospitalization ; Humans ; Information Systems ; Intensive Care Units ; International Classification of Diseases ; Korea* ; Mortality ; Pneumonia* ; Pneumonia, Aspiration ; Pneumonia, Bacterial ; Pneumonia, Viral