(P-IG-30) Pathogen Reduction Reduces ABO Isoagglutinin Titers in Apheresis Platelets

Ensuring compatibility between donor and recipient blood types for platelet transfusions remains paramount to prevent adverse reactions, including hemolytic transfusion reactions. The quantitative assessment of ABO isoagglutinin titers is crucial for evaluating the compatibility of platelet products with recipient blood, particularly in pediatric patients. This study aims to evaluate ABO isoagglutinin titers, both IgM and IgG classes, in platelet donations using solid-phase technology by comparing titers between donor retention samples and final platelet product post-compound adsorption device (CAD) samples used for pathogen reduction.

Study

Design/Methods: Sixty platelet donations were analyzed, comprising 30 type O, 15 type A, and 15 type B donors, with each donation providing two samples: donor retention samples collected (in EDTA tubes) at the time of apheresis, and final platelet product post-CAD samples collected after manufacturing. Samples were tested for Anti-A and/or Anti-B for both IgM and IgG isoagglutinin classes, totaling 360 individual tests, split evenly between retention and post-CAD samples.

Results/Findings:

The distribution of titer results for IgM class isoagglutinins showed post-CAD results with a median titer of 8, a mode of 8, and a sample coefficient of variation (CV) of 0.50 (in titer steps), with retention results having a median titer of 16, a mode of 16, and a CV of 0.42 with p< 0.05. The distribution for IgG class isoagglutinins showed post-CAD results with a median titer of 16, a mode of 128, and a CV of 0.65, with retention results having a median of 32, a mode of 128, and a CV of 0.61 with p< 0.05 (Figure 1). The distribution of all blood group results utilizing maximum titers per sample was determined. Since type O has antibodies of both Anti-A and Anti-B specificity, the higher of the two results was used for the maximum titer determination. The IgM distribution had 82% of all post-CAD samples and 68% of all retention samples yielding titer results ≤ 32. In the case of IgG class, 65% and 62% of post-CAD and retention results, respectively, were ≤ 32.

Conclusions: The ABO blood group system plays a pivotal role in transfusion medicine. By comparing titers between donor retention samples and final platelet product post-CAD samples, the study aimed to evaluate the impact of the manufacturing process on isoagglutinin levels. The results revealed notable differences in the distribution of isoagglutinin titers between retention and post-CAD samples. These differences in titer suggest that the manufacturing process, including CAD utilization, decreases isoagglutinin levels in platelet products. These findings have implications for transfusion practices, especially for pediatric patients, suggesting that pathogen reduced platelets are less likely to cause adverse events related to out of group platelet transfusions.