A Prospective Observational Study to Compare Heat Inactivated ABO Isoagglutinin Titres Performed by CTT and CAT with Solid Phase Red Cell Adhesion (SPRCA) in O Blood Group Individuals

Abstract

Background and aims: Measurement of actual concentration of IgG requires methods like heat inactivation (HI) of plasma. This study was aimed at comparing of heat treated ABO titers performed by conventional test tube technique (CTT) and column agglutination technique (CAT) with HA/SPRCA. 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. All samples were tested by CTT and CAT before and after HI (pCTT, pCAT) and with HA/SPRCA.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 SPRCA, while pCAT IgG titers were higher with pCAT when compared to HA/SPRCA. Results of titers obtained by pCTT were lower as compared to pCAT and HA/SPRCA, with majority giving results less than 64. Median IgG and IgM titers for both anti-A and anti-B were highest in pCAT, while median IgG and IgM anti-A and anti-B titers were similar with 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 inter-observer variation. Titers obtained by pCAT were higher in comparison to HA/SPRCA and pCTT results, due to high sensitivity.