Identification of the novel HLA-B*15:18:01:04 in a Korean individual.

HLA-B*15:18:01:04 differs from HLA-B*15:18:01:02 by single nucleotide substitution at position 2176 (G > A).

HLA-B*40:302, a novel allele identified by sequence-based typing in a Korean individual.

B*40:302 differs from B*40:02:01:01 by a single nonsynonymous nucleotide substitution at codon 81 (CCG→CTG).

Identification of HLA-B*58:01:21, a novel allele in a Korean individual.

B*58:01:21 has a single nucleotide change, c.264A>G (ACA→ACG at codon 88) compared with B*58:01:01:01.

HLA-DPB1*518:01, a new allele identified by sequence-based typing in a Korean individual.

The new allele DPB1*518:01 showed one nucleotide difference with DPB1*13:01:01 at codon 124 (CCT/ACT).

HLA-DPB1*519:01, a new allele identified by sequence-based typing in a Korean individual.

The new allele DPB1*519:01 showed one nucleotide difference with DPB1*13:01:01 at codon 234 (GTG/ATG).

HLA-A*24:02:01:09, a new allele identified by sequence-based typing in a Korean individual.

One nucleotide insertion between residues 1804 and 1805 of HLA-A*24:02:01:01 results in a new allele, HLA-A*24:02:01:09.

A novel cis-AB variant allele arising from a de novo nucleotide substitution c.796A>G (p.M266V) in the B glycosyltransferase gene.

BACKGROUND: Cis-AB, a rare ABO variant, is the result of a mutated ABO gene that produces a glycosyltransferase enzyme with dual A and B glycosyltransferase activity. It may lead to ABO discrepancies and a delay in establishing the blood group. To date, there have been no reports of a de novo mutation leading to a cis-AB allele. OBJECTIVES AND METHODS: Sequencing of the ABO gene using blood and hair follicle cells from the proposita were performed along with blood from her parents. To establish maternity and paternity, short tandem repeat (STR) analysis was also performed. The A and B enzyme activities of the novel enzyme were measured in an in vitro expression study. RESULTS: A novel cis-AB allele arising from nucleotide substitution c.796A>G (p.M266V) in the B glycosyltransferase gene were discovered in the blood and hair follicle cells from the proposita, which was absent from her parents. In all 15 autosomal STR loci analysed, the probability of maternity and paternity were 0.999999 and 0.999989, respectively. The novel enzyme created 33.1% and 60.2% of A and B antigen compared to wild type A and B glycosyltransferases. CONCLUSION: A novel mechanism leading to a cis-AB allele was discovered.

Application of bone marrow samples for discrimination of acute promyelocytic leukemia from other types of acute leukemia using the routine automated hematology analyzer.

INTRODUCTION: Unreported parameters produced by automated blood cell counter, particularly large unstained cells (LUC) and delta neutrophil index (DNI), indicated the presence of immature and possibly abnormal cell populations in white blood cell population. The purpose of this study was to investigate the laboratory performance for discrimination of acute promyelocytic leukemia (APL) cells from other types of leukemia cells and clinical value of LUC and DNI parameters in bone marrow (BM) samples of patients with acute leukemia. METHODS: A total of 73 BM samples of patients with various type of acute leukemia were analyzed. LUC and DNI parameters were determined by an automated hematology analyzer (ADVIA 120; Siemens Healthcare Diagnostics, New York, NY, USA). Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U methods. Receiver operating characteristic curve (ROC) analysis, survival analysis, and Cox proportional hazard model were used to evaluate the clinical implication. RESULTS: There were significant differences (P < 0.05) between APL group and other group in the DNI and LUC values except for DNI between APL group and non-APL myeloid leukemia group. The area under curve of LUC was larger than that of DNI from the ROC analysis for discrimination between APL group and other group. High LUC value was associated with the increased risk of adverse outcomes and the worse overall survival in patients with acute leukemia. CONCLUSION: Delta neutrophil index and LUC in BM showed discriminating power of APL cells from other leukemia cells.

A new HLA-C allele, C*06:99, identified by sequence-based typing in a Korean individual.

The C*06:99 allele substitutes one nucleotide of C*06:02:01:01 at codon 50 (CCG→CTG), Pro to Leu.

A new HLA-C*07:244 allele identified by sequence-based typing in a Korean individual.

The C*07:244 changes single nucleotide of C*07:02:01 at codon 75 (CGA → CAA), Arg to Gln.

HLA-A*02:07:02, a new allele identified by sequence-based typing in a Korean individual.

The new allele A*02:07:02 shows a single nucleotide substitution compared with A*02:07:01 at codon 233 (ACC → ACT) without any amino acid change.

Distinctive hematological abnormalities in East Asian neonates and children with Down syndrome.

INTRODUCTION: Neonates with Down syndrome (DS) are predisposed to developing transient abnormal myelopoiesis (TAM) and acute myeloid leukemia (AML) associated with DS. However, there is a paucity of data on hematological aberrations and GATA1 mutations in neonates with DS in East Asian populations. METHODS: Total 109 patients with DS who had one or more CBCs obtained were enrolled. The molecular analysis of the GATA1 gene performed in 10 patients (three TAM, three AML associated with DS at diagnosis, one remission case of AML associated with DS and three DS without TAM or AML). RESULTS: East Asian DS neonates showed low frequency of thrombocytopenia, uncommon neutrophilia and higher prevalence rate of TAM compared to previous reports from western countries. GATA1 mutations were identified in almost all TAM and AML associated with DS samples, but were not detected in the samples from DS without TAM or AML associated with DS. CONCLUSION: East Asian DS neonates and children showed distinctive spectrum of hematological abnormalities.

Comparison of the technical and clinical performance of the Elecsys HBsAg II assay with the Architect, AxSym, and Advia Centaur HBsAg screening assays.

South East Asia has some of the highest prevalence rates of hepatitis B virus (HBV) infection (>or=8%) in the world, and the emergence of hepatitis B surface antigen (HBsAg) mutant strains is a growing problem. Assays with the highest levels of sensitivity, including mutant detection, should be used for routine HBsAg screening. In this large multicenter study, the clinical and technical performance of the fully automated Elecsys HBsAg II assay was compared with the Architect, AxSYM, and Advia Centaur HBsAg assays for HBsAg screening. Nine laboratories (three each from Thailand, Korea, and Singapore) compared the Elecsys HBsAg II assay with their routine HBsAg screening assay against a range of stored and routine clinical samples, including recombinant mutants. The Elecsys HBsAg II assay demonstrated equivalent sensitivity and specificity to the Architect HBsAg assay. However, the Elecsys HBsAg II assay recognized a native mutant sample (L94S, L97V, L98V, T123A) that the Architect HBsAg assay failed to detect. The AxSYM and Advia Centaur HBsAg assays appeared less sensitive for the detection of early HBV infection and also failed to detect some of the recombinant mutant strains. There was almost complete agreement between the Elecsys HBsAg II assay and comparator assays with respect to routine serum samples. The results of this study demonstrate that the Elecsys HBsAg II assay is a highly sensitive and specific screening assay for HBsAg and detects reliably the most important and clinically relevant HBV mutants and genotypes. It is suitable for routine HBsAg screening in Asia.

Cutaneous abscess by Trichosporon asahii developing on a steroid injection site in a healthy adult.

We report a rare case of cutaneous abscess by Trichosporon asahii in an immunocompetent adult. A 31-year-old Korean woman presented to our hospital with a cutaneous abscess. She had received an intralesional steroid injection 4 months earlier on the site of a hypertrophic scar. Direct sequencing of the intergenic spacer regions of the rRNA genes identified T. asahii. The decreased local immunity after the steroid injection might have triggered the infection by T. asahii. A cutaneous abscess formation by T. asahii in an immunocompetent patient is an unusual cutaneous finding that to our knowledge has not been reported previously. The local immune reaction of the skin is important for the prevention of Trichosporon infection.

Chimerism and mosaicism are important causes of ABO phenotype and genotype discrepancies.

Discrepancies between blood group genotype and RBC phenotype are important to recognize when implementing DNA-based blood grouping techniques. This report describes two such cases involving the ABO blood group in the Korean population. Propositus #1 was a 22-year-old healthy man undergoing pretransfusion testing for minor surgery. Propositus #2 was a 23- year-old male blood donor. RBCs from both propositi were determined to be group AB and demonstrated unusual agglutination patterns on forward typing, which were inconsistent with their ABO genotype determined by allele-specific (AS) PCR. RBCs from propositus #1 demonstrated mixed field agglutination with both anti-A and -B, while RBCs from propositus #2 demonstrated mixed field only with anti-A reagents. Both had B/O genotypes by AS-PCR. Cloning and sequencing of ABO exons 6 and 7 revealed three alleles in both propositi: propositus #1: A102/B101/O04; propositus #2: A102/B101/O01. A panel of nine short-tandem repeat (STR) loci was tested on DNA extracted from blood, buccal mucosal cells, and hair from the propositi and on DNA isolated from their parents' blood. In all tissues tested from propositus #1, three loci demonstrated a double paternal and a single maternal DNA contribution, indicating that he was a chimera or a mosaic; in those from propositus # 2, one STR locus demonstrated a double paternal DNA contribution, indicating that he was a tetragametic chimera. Chimerism and mosaicism are uncommon but important causes of ABO genotype and phenotype discrepancies. The evaluation of patients and donors with unusual or unexpected serology in pretransfusion testing and consensus ABO alleles may include the evaluation of STR loci to detect these phenomena.

The genetic and phenotypic basis of blood group A subtypes in Koreans.

A serological and genetic study of Korean blood donors with phenotypic group A subtypes was performed. There were 176 donors with phenotypic A subtypes identified. Exons 6 and 7 from 57 representative donors were sequenced. The A(var) allele (784 G > A) was cloned and sequenced, and a family study demonstrating its inheritance and unusual serological characteristics was performed. The A102 allele was the most frequently identified allele in phenotypically A2 (58%, 11/19) and A2B (68%, 17/25) donors. Anti-A1 was rarely present amongst A2 and A2B donors. The family study revealed that the A(var) allele was expressed as phenotype A(weak)B in A(var)/B heterozygote members, but as phenotype O in A(var)/O heterozygotes. The most frequent allele in Korean donors with the A2 phenotype differs from its Caucasian counterpart, as does the frequency of anti-A1. The A(var) allele demonstrates allelic enhancement in A(var)/B heterozygotes.

The serological and genetic basis of the cis-AB blood group in Korea.

BACKGROUND AND OBJECTIVES: The cis-AB blood group is rare, although relatively common amongst Koreans. The serological characteristics and genetic basis of Korean cis-AB blood donors were investigated. MATERIALS AND METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), designed to detect the cis-AB01 allele, was performed on 194 AB samples which demonstrated weak or unusual expression of either or both of the A or B antigens. RESULTS AND CONCLUSIONS: Sixty cis-AB01 donors were identified. cis-AB01/O01 or O02 were the most common genotypes (36/60) detected only in A(2)B(3) donors, and cis-AB01/B101 (nine of 60) was the least common genotype identified only in A(2)B donors. Surprisingly cis-AB01/A102 (15/60) was identified in a variety of phenotypes (A(1)B(3), A(1)B(x) or el, A(int)B(3)).

Molecular typing of vibrio vulnificus isolated from clinical specimens by pulsed-field gel electrophoresis and random amplified polymorphic DNA analysis.

Primary V. vulnificus septicemia has been continuously reported in Korea. We analyzed the molecular diversity of V. vulnificus strains isolated from clinical specimens using pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) analysis. We analyzed a total of 23 V. vulnificus strains isolated from 22 patients between 1992 and 1997. RAPD analysis was performed using five random primers, and we obtained chromosomal DNA restriction patterns with NotI and SfiI by PFGE. Two isolates from one patient disclosed similarity value 1.0 by RAPD and had an indistinguishable pattern when analyzed with PFGE, which indicated that they were the same strains. The remaining 22 isolates from 22 patients could be separated into 5 different molecular types in RAPD analysis. The range of similarity values among the isolates was wide (0.29-0.81). Of 22 strains, four strains could not be typed in repeated trials by PFGE with NotI and SfiI. The PFGE patterns of 18 strains showed a remarkable polymorphism consisting 12-19 fragments (20-870 kb). These results show that V. vulnificus strains isolated from Korea are genetically diversified for the most part.