Oral Concurrent Session 5 - Medical & Surgical Complications
Oral Concurrent Sessions
Marie Elise Abi Antoun, MD
Resident Physician
Tufts University School of Medicine
Boston, MA, United States
Red blood cell alloimmunization (AI) limits transfusion options and confers risk of hemolytic disease of the fetus and newborn (HDFN). Antigens D, c, E and Kell are particularly pathogenic. Few institutions in the United States routinely match donors for more than ABO and D antigen (ABO+D) when alloantibodies are absent. Several studies have compared new AI among recipients of blood matched for ABO+D to blood additionally matched for c, E and Kell (ABO+D+cEK). The aim of this study was to systematically review and meta-analyze their outcomes.
Study Design:
Three online databases (Medline via PubMed, Scopus, Embase) were searched for prospective and retrospective cohort studies comparing ABO+D and ABO+D+cEK donor match protocols where new AI was a primary outcome. Case reports, literature reviews and studies of non-human subjects were excluded. The search protocol was peer-reviewed and published on the PROSPERO international database of meta-analyses (CRD42023411620). Two teams of two reviewers independently screened studies; conflicts resolved by a fifth reviewer. Data were extracted according to Cochrane guidelines; risk of bias measured using ROBINS-I and RoB-2 tools. Random effects meta-analysis was used to combine effect estimates.
Results:
In total, 3,533 studies were reviewed. Among 10 that met inclusion criteria, 85,385 patients were transfused, of whom 43.3% (36,980) received only ABO+D+cEK matched blood. ABO+D+cEK was associated with significantly lower rate of new AI compared with ABO+D (OR: 0.36, 95% CI: 0.18-0.74). Secondary analyses showed similar reductions when excluding studies of intrauterine fetal transfusions (OR 0.27, 95% CI: 0.13-0.58) and when only examining c, E or Kell antigen AI (OR 0.26, 95% CI: 0.13-0.53). As expected, no reduction in D antigen AI was noted (OR 0.77, 95% CI: 0.24-2.52).
Conclusion:
New alloimmunization is significantly reduced when using an ABO+D+cEK match protocol. Given sequelae of alloimmunization in pregnancy and thereafter, establishing routine use of ABO+D+cEK donor match in adults of pregnancy potential merits consideration.