Comparison of IgG ABO Antibody Titers using Conventional Tube Test and Hydrogel Medium

Abstract

Background: ABO antibodies are clinically important in blood transfusion practice. ABO antibody titration has
been used to evaluate patient outcomes, especially in ABO-incompatible stem cell and solid organ transplantation
and to assess ABO-incompatible transfusion responses. Objective: This study aimed to detect IgG anti-A and
anti-B antibodies in group O Thai blood donors by indirect antiglobulin test (IAT) using conventional tube test
(CTT) and hydrogel medium (HDM). Materials and Methods: Altogether, 100 serum samples obtained from
group O healthy blood donors of the National Blood Centre, Thai Red Cross Society, Bangkok, Thailand were
included. IgG anti-A and anti-B titers were tested by IAT using CTT and HDM without washing step. The
results of antibody titers and agglutination scores were compared. Results: Among 100 blood donors, there
were 51 males and 49 females (M:F = 1:1) and their ages ranged from 18 to 58 years. There were no association
between IgG anti-A and anti-B agglutination scores and titers with age and gender. The IgG anti-A, and anti-B
titers using IAT-CTT yielded higher agglutination scores than IAT-HDM (p < 0.001). However, a good correlation
was obtained in the agglutination titers (anti-A, r = 0.7583 and anti-B, r = 0.7145). To assess the repeatability of
IgG ABO antibody detection by IAT using HDM, the mean, standard deviation and coefficient of variation (CV)
of 3 serum samples tested in quintuplicate. The CV of agglutination scores is within 5%. Conclusion: From this
study, the HDM can be used to perform IAT for determination of IgG ABO antibody titers in order to eliminate
washing step. Moreover, it provides reliable results and reproducible testing but the antibody titers tested by
IAT-HDM were less than IAT-CTT.