The evanescence and persistence of RBC alloantibodies in blood donors

Abstract

BACKGROUND Blood donors represent a healthy population, whose red blood cell (RBC) alloantibody persistence or evanescence kinetics may differ from those of immunocompromised patients. A better understanding of the biologic factors impacting antibody persistence is warranted, as the presence of alloantibodies may impact donor health and the fate of the donated blood product. METHODS Donor/donation data collected from four US blood centers from 2012 to 2016 as part of the Recipient Epidemiology and Donor Evaluation Study‐III (REDS‐III) were analyzed. Clinically significant antibodies from blood donors with more than one donation who underwent at least one follow‐up antibody screen after the initial antibody identification were included. Of 632,378 blood donors, 481 (128 males and 353 females) fit inclusion criteria. RESULTS Antibody screens detected 562 alloantibodies, with 368 of 562 (65%) of antibodies being persistently detected and with 194 of 562 (35%) becoming evanescent. Factors associated with antibody persistence included antibody specificity, detection at the first donation, reported history of transfusion, and detection of multiple antibodies concurrently. Anti‐D, C, and Fya were most likely to persist, while anti‐M, Jka, and S were most frequently evanescent. CONCLUSIONS These data provide insight into variables impacting the duration of antibody detection, and they may also influence blood donor center policies regarding donor recruitment/acceptance.

Routine donor red cell antibody screening: Considering the alternate strategy

“…Red blood cell (RBC) alloantibodies can also fall beneath the level of detection. This is a property known as antibody evanescence which has been found to occur with 35% of alloantibodies in healthy blood donors and can be considered in this case [13].…”

Screening for new red blood cell alloantibodies after transfusion in patients with sickle cell disease

“…This serious and sometimes fatal complication can be avoided if the pre‐transfusion testing identifies an antibody to the specific antigen and the patient is then transfused RBCs negative for this antigen. Unfortunately, RBC alloantibodies often evanesce to undetectable levels 17‐23 . In one study of alloimmunized patients with SCD, 81% of patients had at least one previously identified antibody that was later not detected because of evanescence 24 .…”

“…They found that while some RBC alloantibodies were detected as early as 30‐days post‐transfusion, most new alloantibodies were not detected until 60‐days post‐transfusion, with a few new alloantibodies not being detected until after 100 days 27 . Antibody evanescence has been found to be related to RBC alloantibody antigen specificity and can occur after only a few weeks to years after initial antibody detection 17,18,20,21 …”

“…Unfortunately, RBC alloantibodies often evanesce to undetectable levels. [17][18][19][20][21][22][23] In one study of alloimmunized patients with SCD, 81% of patients had at least one previously identified antibody that was later not detected because of evanescence. 24 In these situations, the immediate pre-transfusion antibody detection test (antibody screen) is negative, yet when the immune system is challenged with the antigen, there is a rapid amnestic increase of antibodies that cause a delayed hemolytic transfusion reaction (DHTR).…”

“…27 Antibody evanescence has been found to be related to RBC alloantibody antigen specificity and can occur after only a few weeks to years after initial antibody detection. 17,18,20,21 In an effort to prevent DHTRs in our patients with SCD, we initiated prospective assessment for RBC alloantibody development following acute, inpatient transfusions in an attempt to identify antibodies before they evanesce. This initiative was implemented as a new clinical protocol at our pediatric hospital, which serves a large population of children and adolescents with SCD.…”