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.

Isoagglutinin Titer in Major ABO Incompatible Bone Marrow Transplantation / 대한수혈학회지

BACKGROUND: Major ABO incompatibility between donor and recipient is not a barrier for successful bone marrow transplantation(BMT). However, isoagglutinins could cause serious adverse effects, such as engraftment failure, delayed hematopoiesis and delayed hamolysis. It is important to detect these complications and bone marrow engraftment at an early stage for appropriate management. We have investigated the usefulness of isoagglutinin titer in major ABO incompatible BMT. METHODS: During April, 1996 to September, 1997, thirteen cases underwent major ABO-incompatible BMT at Asan Medical Center. We reviewed their medical records and performed ABO blood typing, IgM and IgG isoagglutinin titration, direct antiglubulin test and test for A and B transferase activities. RESULTS: Isoagglutinins against the donor antigen disappeared in 9 cases, decreased in 3 cases and persisted in 1 case. One patient who had persistent isoagglutinin titer had not had a bone marrow engraftment. The average time for anti-A isoagglutinin titer to disappear was 167.8 days(range; 90-281) and for anti-B was 116.8 days(range; 30-276). Eleven out of 13 cases, the RBCs of donor type appeared. On the average, RBCs of group A appeared later than RBCs of group B (112.7 +/- 99.6 days vs. 71.4 +/- 92.0 days, P>0.05). In 7 out of 8 cases that were done the A and B transferases test, the donordegrees empty set s RBC was produced but very little or none of the donor type transferase appeared in the serum. CONCLUSION: In order to determine the erythroid engraftment after the major ABO incompatible BMT, it is necessary to check the isoagglutinin titer periodically.

Evaluation of ABO Isoagglutinin Titers in Korean Adults / 대한수혈학회지

BACKGROUND: Isoagglutinin titers may be useful markers in the assessment of ABO-incompatible transfusion, bone marrow transplantation, and solid organ transplantation as well as determination of ABO subtypes, and screening of B cell defect. ABO isoagglutinin titers can be differed according to age, gender, race, and environmental factors. We determined isoagglutinin titers of IgM anti-A, anti-B in Korean healthy adults. METHODS: Sera from 215 adults of blood group A, B, and O were tested. IgM isoagglutinin titers were determined by mixing the two fold serum dilutions from 1:2 to 1:512 with pooled 3% red blood cells. Tests were read after spinnig the tubes at 3400 rpm for 15 seconds. RESULTS: The results were analyzed according to the ABO types, ages, and sex. From 77 sera from group A (44 male, 33 female), the geometric mean of IgM anti-B titers in group A was 73.5 (male 84.4, female 61.4), and the median was 64 (male 64, female 64). From 68 sera from group B (36 male, 32 female), the geometric mean of IgM anti-A titers in group B was 64.0 (male 64.0, female 65.3), and the median was 64 (male 64, female 64). From 70 sera from group O (64 male, 28 female), the geometric means of IgM anti-B and anti-A titers in group O were 52.3 (male 42.2, female 72.5) and 64.4 (male 63.1, female 70.5), respectively. And the median were 64 (male 32, female 64) and 64 (male 64, female 64), respectively. There were no linearity of isoagglutinin titers with the increase of age in Korean adults from 20 to 69 years old. CONCLUSION: The titers of IgM anti-B and anti-A isoagglutinin in Korean adults were estimated to be equally 1:64. No decrease of ABO isoagglutinin titers were observed with the increase of age from 20 to 69 years old.