Comparative Evaluation of Five Different Methods of Anti‐ABO Antibody Titration: An Aid for ABO‐Incompatible Organ Transplants

Abstract

The accurate estimation of ABO antibody titers is of the utmost importance in organ transplants involving ABO incompatibility. We aim to compare five different methods of titration and analyze the data. Samples of 48 O group blood donors who donated during the month of December 2015 to January 2016 in our institution were subjected to ABO antibody titration by five different methods: immediate spin (IS) tube titer, antihuman globulin phase tube titer, Coomb's gel card titer, gel card titer after dithiotreitol (DTT) treatment of plasma, and the solid phase red cell adherence method. The mean number of titer serial dilution steps in the different titer estimation methods was compared using the paired t-test and McNemar test. A correlation between the methods was tested using Spearman's rho and kappa statistics. The median antiglobulin (AHG) phase tube titers were found to be the highest anti-A (128) and anti-B (192) titers. Significant differences in the ABO antibody titer readings among the five different methods were noted. Titers were reduced by DTT treatment in nearly 50% samples tested for both anti-A and anti-B titers. Average agreements between the DTT-applied AHG phase gel card titers and the solid phase red cell adherence (SPRCA) titers was observed for anti-A (κ = 0.473) and anti-B (κ = 0.530). The AHG phase tube and gel cards titers showed poor agreements. There are differences in the interpretability of the ABO antibody titer among different techniques. Consistent and uniform application of the method for titration throughout the treatment of a patient is highly essential.

Hemolytic markers following the transfusion of uncrossmatched, cold‐stored, low‐titer, group O+ whole blood in civilian trauma patients

“…Both parameters are left to the hospital's discretion. There can be considerable variability in anti‐A and ‐B titer measurements between centers, in particular when different testing modalities are employed . A recent survey demonstrated that there is a range of clinical practice, with the maximum number of LTOWB units ranging from two units to as many units as a hospital has in their inventory, and the maximum titer thresholds included less than 50, less than 100, less than 128, and less than 256 .…”

Isohemagglutinin titering performed on an automated solid‐phase and hemagglutinin‐based analyzer is comparable to results obtained by manual gel testing

“…While relatively inexpensive, manual dilution is both labor intensive and subjective, conferring significant interoperator variation. For this reason, differences of less than two dilutions are generally not deemed to be significant . Unless the plasma is treated with DTT before testing, the titers assessed by gel column are generally considered to reflect a combination of IgM and IgG class antibodies .…”

“…For this reason, differences of less than two dilutions are generally not deemed to be significant. [14][15][16][17][18][19] Unless the plasma is treated with DTT before testing, the titers assessed by gel column are generally considered to reflect a combination of IgM and IgG class antibodies. 19 This is important, given that the blood bank is generally mainly concerned about the clinical effects of incompatible IgM class isoagglutinins, while transplant physicians are generally most concerned about the clinical effects of incompatible IgG class isoagglutinins.…”

For the many: permitting deceased donor kidney transplantation across low‐titre blood group antibodies can reduce wait times for blood group B recipients, and improve the overall number of 000MMtransplants ‐ a multicentre observational cohort study

“…There are of course potential barriers to implementation of this allocation scheme. Access to reliable out of hours ABO‐antibody measurements is one concern, particularly in the light of evidence suggesting the variability in titre measurements with different techniques . Another is the perceived increased immunological risk of ABOi transplantation.…”