Molecular Genetic and Serologic Analysis of the O allele in the Korean Population / 대한수혈학회지

BACKGROUND: The recent expansion of knowledge about various ABO alleles has led to the need for a comprehensive measure to cover the numerous polymorphisms dispersed in the ABO gene. A few studies have examined the diversity of the O allele compared to A or B subgroup alleles, resulting in antigenic changes. This study investigated the relationship between the serologic and molecular genetic characteristics of the O alleles in the Korean population. METHODS: One hundred and five samples from healthy blood group O subjects were selected randomly. The isoagglutinin titer was measured using a tube agglutination and gel microcolumn assay. The ABO alleles were analyzed by sequencing exons 6 and 7 of the ABO gene. When the origin of a heterozygous nucleotide sequence was ambiguous, it was separated into a single allele using mono-allele amplification or cloning. RESULTS: The median IgM isoagglutinin titer was eight. In contrast, the median IgG anti-A and anti-B isoagglutinin titers were 64 and 32, respectively. The IgG isoagglutinin titer showed a significant increase with age (P<0.0001). Six O alleles were observed in 105 blood group O populations by sequencing. The O01 and O02 alleles were common (0.57, 0.36). Three rare O alleles (O04, O05, and O06) and one novel non-deletional O allele were found. CONCLUSION: The distribution of isoagglutinin titers of blood group O and the genetic frequency of O alleles in this study would form the basis of the development and interpretation of ABO genotyping and serologic workup in the Korean population.

Evaluation of ABO Antibody Titration Using Tube and Column Agglutination Techniques

BACKGROUND: ABO antibody titration is useful for the evaluation of ABO-incompatible bone marrow or solid organ transplantations, yet the results quite vary between different test methods used. We compared the results of microcolumn agglutination and tube methods. METHODS: Anti-A and anti-B isoagglutionin titers were determined in 63 healthy individuals (23 O, 20 A, and 20 B blood groups) using 4 different methods: immediate spin tube (tube), microcolumn agglutination without anti-human globulin (AHG) (CAT), tube with AHG (tube-AHG) and microcolumn agglutination with AHG (CAT-AHG). RESULTS: The median (range) titers of anti-A and anti-B in group O individuals by tube, CAT, tube-AHG, and CAT-AHG methods were 64 (8-512), 64 (8-512), 128 (8-2,048), and 128 (16-2,048); 64 (16-128), 128 (16-256), 128 (16-512), and 256 (16-512), respectively. The median (range) titers of anti-A in group B and anti-B in group A individuals by the four methods were 64 (16-128), 128 (8-128), 128 (8-256), and 256 (8-256); 64 (8-128), 64 (8-128), 32 (8-128), and 64 (8-256), respectively. The isoagglutinin titer measured by CAT-AHGmethod was the highest. The titers measured by CAT and CAT-AHG methods were 0-1 titer higher than those by tube and tube-AHG methods, respectively. Whatever method was used, the isoagglutinin titers were higher in women than in men. CONCLUSIONS: CAT-AHG was the most sensitive method among the four methods tested. Since AHG titer values are critical for the clinical management and CAT has less manual procedures than tube method, CAT-AHG method could be used for the standardization of ABO antibody titration in different institutions.

Comparison of ABO Isoagglutinin Titers by Different Tube Hemagglutination Techniques / 대한수혈학회지

BACKGROUND: The ABO isoagglutinin titer is useful for the evaluation and observation of ABO incompatible bone marrow transplantation or organ transplantation, yet the results can be different depending on the test methods. Measurement of isoagglutinin titer using the gel test has recently been reported, but this test is expensive. In this study, we investigated isoagglutinin titer distribution of normal individuals using the different tube hemagglutination technique to help select the best test method and to interpret the agglutinin titer. METHODS: Normal healthy individuals were selected from those patients who underwent a physical examination at Ajou University Hospital, during July 2009. Sixty healthy individuals, (10 men and 10 women per each ABO blood group) were recruited for the study. The immediate spin method (IS), the anti-human globulin method with dithiothreitol treatment (DTT-AHG) and the anti-human globulin method without DTT treatment (AHG) were performed simultaneously. The reciprocal of the highest serum dilution that showed macroscopic agglutination 1+ or more was regarded as the isoagglutinin titer. RESULTS: The isoagglutinin titer measured by the AHG was the highest in the all blood groups. In case of blood groups A and B, the isoagglutinin titer by the IS was higher than that by the DTT-AHG, but this was quite the reverse in the case of the blood group O. CONCLUSION: If it is not necessary to distinguish IgM antibody and IgG antibody, then it seems that the AHG is the best practical method of those three methods. It was more sensitive than the IS and more rapid and easier than the DTT-AHG.