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.

ABO Genotyping of a Neonate with Mixed Field Agglutination / 대한수혈학회지

Mixed field agglutination is an important, but rare phenomenon of ABO blood grouping. Contrary to adults, neonatal red blood cells are immature and they present a weak ABO expression, and sometimes this result in a mixed field agglutination pattern. We report here on a case of a neonate who presented with mixed field agglutination on the ABO blood grouping during serologic testing and the neonate had a normal ABO genotype.

Using Genotyping to Identify an A1B(weak) Blood Group / 대한수혈학회지

Since an exact ABO blood type match is essential for transfusion therapy, any ABO discrepancies should be resolved prior to the issuing of blood. The authors confirmed the ABO blood group of a 50-year-old male using genotyping. On a routine blood group test, the cell type was A+; however, anti-B was undetected in his serum. To determine the cause of this ABO discrepancy, an adsorption elution test and saliva test were performed. The presence of a weak B substance was suspected despite no evidence of the B antigen on red blood cells. Polymerase-chain-reaction restriction-fragment-length-polymorphism (PCR-RFLP) and sequencing analysis of exons 6 and 7 demonstrated that his blood type was A1Bweak (the A allele tested as the A105 subtype, while the B allele was most similar to the B302 subtype). Again, using genotyping, we subsequently confirmed the A1Bweak blood type in a leukemic patient who was in complete remission.