A prospective observational study to compare abo isoagglutinin titer by conventional test tube and column agglutination technique after heat inactivation of plasma in O blood group individuals

Abstract

Background and Aims: When determining ABO antibody titers, IgG antibodies can be masked by immunoglobulin M (IgM) antibodies. Hence, the measurement of actual concentration of IgG requires methods such as heat inactivation (HI) of plasma. This study was aimed at determining the effects of HI on IgM and IgG titers performed by conventional test tube (CTT) technique and column agglutination technique (CAT). Materials and Methods: This was a prospective, observational study conducted from October 2018 to March 2020. All consecutive O group donors who gave consent for participation were included in the study. All samples were consecutively tested by CTT and CAT, before and after HI (pCTT and pCAT). Results: A total of 2005 donors were included. IgG titers were found to be more than IgM titers. pCTT IgG results are similar or lower when compared to results obtained by solid-phase red cell adherence (SPRCA), whereas pCAT IgG titers were higher with pCAT when compared to hemagglutination (HA)/SPRCA. The results of titers obtained by pCTT were lower as compared to pCAT and HA/SPRCA, with majority giving results <64. The median IgG and IgM titers for both anti-A and anti-B were highest in pCAT, whereas the median IgG and IgM anti-A and anti-B titers were similar to HA and pCTT. Conclusion: Results obtained by HA/SPRCA were closer to results obtained by pCTT, with the advantage of less time consumption, automation requiring less expertise, and no interobserver variation. Titers obtained by pCAT were higher in comparison to HA/SPRCA and pCTT results, due to high sensitivity.