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1.  Standardization of ABO Antibody Titer Measurement at Laboratories in Korea 
Annals of Laboratory Medicine  2014;34(6):456-462.
Measurement of the ABO antibody (Ab) titer is important in ABO-incompatible transplantation. However, to the best of our knowledge, no standard protocol or external survey program to measure the ABO Ab titer has been established in Korea. We investigated the current status of ABO Ab titer measurements at various laboratories in Korea and the impact of the protocol provided to reduce interlaboratory variations in the methods and results of ABO Ab titers.
The Korean external quality assessment of blood bank laboratories sent external survey samples with a questionnaire to 68 laboratories across Korea for the measurement of ABO Ab titers in May 2012. After 6 months, a second set of survey samples were sent with a standard protocol to 53 of the previously surveyed laboratories. The protocol recommended incubation at room temperature only and use of the indirect antihuman globulin method for the tube test as well as and the column agglutination test (CAT).
Several interlaboratory variations were observed in the results, technical procedures, and methods selected for measurement. We found that 80.4% laboratories hoped to change their protocol to the provisional one. Additionally, CAT showed significantly lower variation among laboratories (P=0.006) than the tube test.
Our study provides baseline data regarding the current status of ABO Ab titer measurement in Korea. The standard protocol and external survey were helpful to standardize the technical procedures and select methods for ABO Ab titer measurement.
PMCID: PMC4215415  PMID: 25368821
ABO blood group system; Antibody; Titer; Standard
2.  Comparison of ABO Antibody Titers on the Basis of the Antibody Detection Method Used 
Annals of Laboratory Medicine  2014;34(4):300-306.
Detection methods for ABO antibody (Ab) titers vary across laboratories, and the results are different depending on the method used. We aimed to compare titer values using different detection methods for the measurement of ABO Ab titers.
For ABO Ab detection, pooled group A or B red blood cells (RBCs) were reacted with each of 20 sera from blood groups A, B, or O without dithiothreitol treatment. The room-temperature (RT) incubation technique and the indirect antiglobulin test (IAT) were used in the tube test and gel card test. Flow cytometry (FCM) was performed by using anti-IgM and anti-IgG Abs.
Regardless of the blood groups tested, the FCM assay with anti-IgM showed the highest titer compared to the tube test and gel card test with RT incubation in both. The tube test with IAT showed a higher titer than the gel card test with IAT (Gel-IAT) or FCM with anti-IgG in blood group A and B, while Gel-IAT showed the highest titer relative to the other tests, only for the anti-A Ab in blood group O.
There were significant differences in the titers depending on the detection method used, and each method showed a different detection capacity for each ABO Ab depending on the ABO blood group tested. Therefore, caution should be exercised in interpreting ABO Ab titer results, taking into consideration the detection method used and the blood group.
PMCID: PMC4071187  PMID: 24982835
ABO blood group system; Titer; Flow cytometry
3.  Effects of Platelet Lysate Preparations on the Proliferation of HaCaT Cells 
Annals of Laboratory Medicine  2013;34(1):43-50.
Standard protocols are lacking for the preparation of platelet lysates (PL) as an alternative to using fetal bovine serum as a cell culture supplement. This study aimed to establish optimum conditions for preparing PL for use in cell cultures.
Cell density in three pooled platelet concentrates (PC) were adjusted to 1×1012/L and 2×1012/L. PL was prepared from PC by 1 to 3 freeze-thaw (FT) cycles. HaCaT cells were cultured in media supplemented with 5% or 10% PL. Cell numbers were estimated using a Cell Counting Kit-8 (CCK-8; Dojindo Laboratories, Japan). Growth factors were quantified by using the Luminex 200 system (Luminex Corporation, USA).
Cell proliferation rates in the presence of PLs were similar when prepared from PCs of both cell densities. The rates were higher in media containing 5% PL than 10% PL when prepared by two FT cycles. Concentrations of vascular endothelial growth factor (VEGF), platelet-derived growth factor-AB/BB (PDGF-AB/BB), PDGF-AA, and epidermal growth factor (EGF) were significantly higher in PL prepared from PC with a cell density of 2×1012/L than 1×1012/L PC. However, only VEGF and PDGF-AA concentrations in PLs were correlated with HaCaT cell counts.
The 5% PL from PC with a cell density of 1×1012/L prepared by two FT cycles treatment was the most effective condition that supported steady HaCaT cell proliferation. Our finding may be useful for preparing PL-supplemented cell culture media.
PMCID: PMC3885772  PMID: 24422195
Platelet lysate; Cell culture; Freeze-thaw; Growth factor; Cell proliferation
4.  The Effects of Helicobacter pylori on the prognosis of patients with curatively resected gastric cancers in a population with high infection rate 
The goal of this study was to assess the correlation between the Helicobacter pylori status of patients who underwent curative resection for gastric adenocarcinoma and their prognosis in Eastern societies where H. pylori infection is prevalent.
Between 2006 and 2007, 192 patients who had a curative resection for the treatment of gastric adenocarcinoma were enrolled in the study. Of these patients, 18 were excluded due to an inexact evaluation of the H. pylori status, thereby leaving 174 patients in the final analysis. Serologic testing for H. pylori was assessed using an enzyme-linked immunosorbent assay kit for immunoglobulin G, and the histological presence of H. pylori was identified using the Giemsa stain.
Of the 174 patients, 111 patients (63.8%) were confirmed for H. pylori infection. H. pylori status did not correlate with the overall or disease-free survival. For patients with stage III or IV gastric cancer, a positive H. pylori status was a significant predictive factor for recurrence over that of a negative H. pylori status (P = 0.019). Negative H. pylori status was a predictive factor for recurrence in multivariable analysis (relative risk, 2.724; 95 confidence interval, 1.192 to 6.228).
Helicobacter pylori status did not correlate with the clinicopathologic factors of gastric adenocarcinoma. However, a negative Helicobacter pylori status may be a predictive factor for recurrence in patients diagnosed with advanced gastric adenocarcinoma.
PMCID: PMC3467386  PMID: 23091792
Helicobacter pylori; Stomach neoplasm; Prognosis; Survival
5.  Current trends in domestic status and insurance policy for use of plasma 
The Korean Journal of Hematology  2010;45(3):147-149.
PMCID: PMC2983038  PMID: 21120199
6.  Genetic Rearrangements of Tn1546-Like Elements in Vancomycin-Resistant Enterococcus faecium Isolates Collected from Hospitalized Patients over a Seven-Year Period▿  
Journal of Clinical Microbiology  2007;45(12):3903-3908.
The heterogeneity of Tn1546 results from point mutations, deletions, and the integration of insertion sequence (IS) elements. Among these variations, the presence of IS elements accounts for much of the heterogeneity. Such a rearrangement could play a key role in the evolution of the vanA gene cluster, and hence, it may modify its transferability. In this study, we characterized the consequence of Tn1546 in vanA-containing Enterococcus faecium isolates collected from patients over time. From 1998 to 2004, 57 vanA-containing E. faecium isolates were collected from hospitalized patients at Ajou University Hospital in Korea. PCR amplification of internal regions of Tn1546 was performed, and both DNA strands were directly sequenced by the dideoxy termination method. All isolates were divided into three main types, including the prototype, according to the distribution of IS elements integrated into Tn1546 elements. Type I was characterized by an IS1542 insertion in the orf2-vanR intergenic region and an IS1216V insertion in the vanX-vanY intergenic region. Type II was represented by the presence of two copies of IS1216V at the 3′ end of IS1542 and in the vanX-vanY intergenic region, as well as IS1542 in the orf2-vanR intergenic region. Seventeen strains isolated from 1998 to 2000 represented type I, and 38 strains isolated from 2000 to 2004 represented type II. The remaining two isolates were the prototype. The tendency for the rearrangement of Tn1546 was that the sequences were shortened as time passed, especially at the left or the right end, and hence, this could gradually modulate their transferability.
PMCID: PMC2168545  PMID: 17898158
7.  Reduction in Glycopeptide Resistance in Vancomycin-Resistant Enterococci as a Result of vanA Cluster Rearrangements 
The molecular characterization of five clinical isolates of vanA-containing vancomycin-resistant enterococci with altered resistance to glycopeptides was examined. One strain represented an IS1216V insertion accompanied by partial deletion of the reading frame of vanX following a transposition event. The other four strains represented IS1216V within the vanX-vanY intergenic region associated with deletion of vanY or vanZ.
PMCID: PMC375328  PMID: 15047548
8.  Autoimmune hemolytic anemia predominantly associated with IgA anti-E and anti-c. 
Journal of Korean Medical Science  2002;17(5):708-711.
A patient with warm autoimmune hemolytic anemia (AIHA) due to predominance of immunoglobulin A (IgA) with an Rh specificity, considered to be the first case in Korea, is described. A 13-year-old male patient with severe hemolytic anemia showed a weak reactivity (1+) in the direct antiglobulin test (DAT) by using anti-IgG antiglobulin reagent. This finding, however, could not fully explain the patient's severe AIHA. When anti-IgA reagent was used for the DAT, strong reactivity (4+) was observed and free anti-E and anti-c autoantibodies were also detected by anti-IgA and anti-IgG reagents. The patient's hemoglobin began to rise with the administration of steroids. Because RBCs coated with multiple types of immunoglobulins are associated with more severe hemolysis than those only with IgG, the DATs using anti-IgA and other reagents are needed for the correct diagnosis when the result of DAT is not compatible with patient's clinical manifestations.
PMCID: PMC3054947  PMID: 12378029

Results 1-8 (8)