A Prospective Study to Compare DTT-Treated ABO Antibody Titers: Conventional Tube Technique vs. Column Agglutination Technique with Solid-Phase Red Cell Adherence

Abstract

Background and Aims: Accurate measurement of IgG isoagglutinin titers often requires treating plasma with dithiothreitol (DTT) to block IgM interference. This study aimed to compare DTT-treated ABO antibody titers in O group donors using two methods: the conventional tube technique (CTT), column agglutination technique (CAT), with solid-phase red cell adherence/hemagglutination (SPRCA/HA). Materials and Methods: A prospective observational study was conducted on 2004 O blood group whole blood donors, from November 2018 to April 2020 who consented to participate in the study. Antibody titers were measured using CTT and CAT, both before and after DTT treatment (pCTT, pCAT), and were also tested using the SPRCA/HA method. Results: A total of 2004 donors were analyzed. IgG titers were generally higher than IgM titers. pCAT had higher titres of IgM (median titre 32) and IgG (median titre 128) for both anti-A and anti-B as compared to pCTT (median IgM titre 8 for both anti-A and anti-B, while median IgG titre 16 for anti-A and 32 for anti-B) as well as SPRCA/HA (median IgM titre 16 for both anti-A and anti-B, while median IgG titre 32 for anti-A and 64 for anti-B) at 1+ strength of reaction considered as end point of the test. pCTT had lower median IgM and IgG titres for both anti-A and anti-B as compared to SPRCA/HA at 1+ strength of reaction. pCTT results matched well with SPRCA/HA (moderate correlation, Spearman’s rho = 0.50–0.58) Conclusion: SPRCA/HA is reliable, automated, and aligns with pCTT, making it useful for clinical labs. However, pCAT’s higher titers may need careful interpretation. More research is needed to confirm clinical implications.