Practice of ABO antibody titration in a transplant center: From tube method to manual gel column testing to automated column agglutination technology.

Abstract

Background and objectives: High-quality ABO antibody titre testing is required for ABO-incompatible haematopoietic stem cell transplantation and kidney transplantation. To assess the feasibility of automated ABO titration as an alternative to manual and semi-automatic titration during the peri-transplant period, a comparative study was conducted internally in a transfusion medicine laboratory.

Materials and methods: This study was performed in two stages. Firstly, the differences in anti-A/B detecting using conventional tube test (CTT) and manual column agglutination technology (CAT) were compared in group O pregnant women. Then, manual and automated CAT were applied to simultaneously detect ABO antibody levels in non-AB-group adult haematological oncology patients.

Results: In the first stage, four groups of 192 comparable results were generated from 48 subjects, which showed a high correlation between CTT and manual CAT (p < 0.001). However, the detection sensitivity of the latter was at least 1 fold higher dilution than that of the former. Fifty-six patients were tested in the second stage by simultaneous manual and automated CAT, and the paired titers differed within an acceptable range (±1 fold dilution). However, the concordance was slightly higher in group IgM (85.4%) than in group IgG (80.5%). Blood group specificity of ABO titers was also observed in this population, and no association between titers and other factors was found.

Conclusion: Automated CAT standardises ABO titre testing and saves labor costs, although manual review of weak positive reactions is still necessary. Due to the blood group specificity of ABO antibodies, special attention should be paid to the quality control and clinical relevance of titre testing for group O recipients in ABO-mismatched transplantation.