Comparison of titer results obtained using immediate spin one‐dilution techniques to a reference method

Abstract

BACKGROUND Many transfusion services determine the titer of potentially incompatible plasma‐containing products by performing a one‐dilution titer at their selected titer threshold. This study compared the results of immediate spin (IS) one‐dilution titers determined by three methods with a reference standard method. METHODS Plasma‐containing products from group A and O donors were titered using the participant's routine IS one‐dilution titer method. No time or temperature incubations were performed, and antihuman globulin reagent was not used. The samples were then tested using a reference method, which was a saline tube test with a 1‐hour room temperature incubation; antihuman globulin was not used in the reference method. The results of the one‐dilution titer were then compared to that obtained in the reference method. RESULTS Nine centers participated in this study. There were 698 antibodies from 374 units tested by the manual IS tube one‐dilution titer method; sensitivity was 0.88 (95% confidence interval [CI], 0.83–0.92), and specificity was 1.00 (95% CI, 0.98–1.00). There were 412 antibodies from 206 units tested by the manual and automated IS buffered gel card one‐dilution titer method; sensitivity was 0.95 (95% CI, 0.91–0.98), and specificity was 0.87 (95% CI, 0.81–0.91). There were 98 antibodies from 49 units tested by an automated microplate IS one‐dilution titer method; sensitivity was 0.76 (95% CI, 0.71–0.93), and specificity was 0.96 (95% CI, 0.92–0.99). All three methods had an accuracy rate of 90% or greater. CONCLUSION The manual and automated one‐dilution titer methods are suitable for screening plasma‐containing units, although more evaluation of the automated microplate method might be required.

Quantification of anti‐A of IgM or IgG isotype using three different methodologies

“…In a large 2017 review of laboratory methods for investigating anti‐A and ‐B in group O WB, 17 none of the six reviewed studies described automated titration methods. In a recent multicenter study comparing one‐dilution antibody titer techniques with a reference test tube method, 6 only 1 of 9 centers used a solid‐phase method for performing the titrations, while the other centers used either test tube or gel card assays. The study did not carry out a direct comparison between the different technologies, as each method was compared only to the reference method.…”

“…6 Several studies that compared methods of titering or measuring anti-A and -B have been published. These studies used manual methods, 6,7 automated methods, [8][9][10] and other technologies such as flow cytometry. 9,[11][12][13] Some studies were focused on transfusion medicine and the use of plasmaincompatible components, while others were focused on ABO incompatible kidney transplantation.…”

How do I implement a whole blood–based blood preparedness program in a small rural hospital?

“…31 The method used for titration may influence the results of the test. 28,32 Studies investigating the variation in anti-A and anti-B titers among healthy volunteers and military personnel observe minimal variation over time. 33,34 However, remeasurement of anti-A and anti-B titer should be performed after potential immunizing events such as pregnancy, transfusion, or serious infection and can be considered after vaccination.…”

“…The most common titer threshold in centers reporting use of whole blood in 2019 was <200 (15/27; 56%) although the range was between <50 and <256 31 . The method used for titration may influence the results of the test 28,32 …”

ABO‐incompatible convalescent plasma transfusion: Yes, you can

“…Anti-B isoagglutinin titration can be performed using high-throughput automated platforms, and, when discordance occurs between platforms, the highest signal should be prudentially used as output reported in the validation label. 4 Blood group O remains the last choice for ABOi plasma transfusion in recipients of group A, B and AB.…”