Current state of transfusion practices for ABO‐incompatible pediatric heart transplant patients in the United States and Canada

Abstract

Transfusion support of children with ABOiHT varies widely among blood banks in the United States and Canada. The choice of blood products and modifications utilized, titer thresholds for organ selection and medical decision points, and antibody reduction strategies are not standardized from center to center. As pediatric ABOiHTs become more common, a better understanding of optimal transfusion support and therapeutic intervention is needed.

ABO blood group antigens and differential glycan expression: Perspective on the evolution of common human enzyme deficiencies

“…As noted earlier, ABO incompatibility may drive additional underrecognized complications ( Blumberg et al., 2018 ; McRae et al., 2021 ; Refaai et al., 2018 ; Sahai et al., 2017 ). Although ABO(H) barriers can now be crossed for solid organ transplantation (which has greatly increased donor availability) ( Irving et al., 2012 ; Tyden et al., 2012 ; Urschel et al., 2013 ), pre-existing anti-ABO(H) antibody titers largely dictate whether successful transplantation occurs ( Dean et al., 2018 ; Janatpour et al., 2008 ; Lee-Sundlov et al., 2020 ; Shirey et al., 2010 ; Urschel and West, 2016 ). Similarly, persistent naturally occurring anti-ABO(H) antibodies likely contribute to the delayed engraftment that can be observed following ABO(H) incompatible hematopoietic stem cell transplantation ( Kimura et al., 2008 ; Shokrgozar and Tamaddon, 2018 ; Tomonari et al., 2007 ).…”

“…Removal of anti-ABO(H) antibodies via apheresis to reduce the anti-A and anti-B antibody titers before and after transplantation can reduce complications of ABO(H) incompatibility. Some transplant centers desire a pre-transplant anti-ABO(H) titer of 1:8 or less to initiate an ABO(H) incompatible renal transplant ( Dean et al, 2018 ; Kozaki et al., 2005 ; Padmanabhan et al., 2009 ; Rivera et al., 2021 ; Wilpert et al., 2007 ). This means that a 1:8 dilution of patient serum is the greatest dilution that still leads to 1 + agglutination (tiny clumps barely visible with the naked eye).…”

A standardized kodecyte method to quantify ABO antibodies in undiluted plasma of patients before ABO‐incompatible kidney transplantation

“…It is not known which assay (kodecyte or A 1 cell assay) has the best correlation with clinical outcome, and this requires clinical trials. The kodecyte method proposed here is also potentially applicable for determining ABO antibody levels in ABO‐incompatible pediatric heart transplantation, production of intravenous immunoglobulin, detecting blood donors with high‐titer ABO antibodies, production of platelet preparations, monitoring ABO‐mismatch bone marrow transplantation, and predicting and monitoring hemolytic disease of the newborn . By eliminating the step of sample dilution and using a standardized reagent RBC, the kodecyte assay has the potential to eliminate the compounding errors of plasma dilution, simplify methodology, make it more suitable for automation, improve standardization between laboratories, and potentially produce a more clinically relevant result.…”

Examining the Role of Complement in Predicting, Preventing, and Treating Hemolytic Transfusion Reactions

“…The pentameric nature of IgM antibodies not only facilitated the detection of ABO(H) polymorphisms by Landsteiner in 1900 but also continues to allow for compatibility testing by leveraging the ability of these alloantibodies to readily agglutinate red blood cells (RBCs) following engagement. Levels of anti-ABO(H) alloantibodies can vary substantially between individuals and are often used as surrogates when assessing the clinical significance of anti-ABO(H) alloantibodies [21]. For example, anti-ABO antibody titers are routinely employed in some healthcare systems to evaluate the clinical significance of anti-ABO antibodies present in platelet and plasma products [22,23].…”