Immunohematology and Genetic Testing (red cells, leukocytes and platelets)
Rebecca Coward, MLS (ASCP), SBB
Supervisor, Transfusion Service
WakeMed
Wake Forest, North Carolina, United States
Disclosure(s): No financial relationships to disclose
Madeline Konicek, MLS(ASCP)SBB (she/her/hers)
Senior Scientist, Immunohematology Reference Lab
Versiti Wisconsin, Wisconsin, United States
Disclosure(s): No financial relationships to disclose
Elizabeth Allen, MD
Associate Professor of Pathology
University of California San Diego, California, United States
Disclosure(s): No financial relationships to disclose
Session Desription: Many common causes of type discrepancies, such as A subgroups, cold-reactive antibodies, and excess serum protein are well-described in literature and well-taught in curricula. However, blood centers and transfusion services frequently encounter various type discrepancies and dilemmas that do not fit into these categories, often manifesting as unexplained mixed-field reactivity or changes in antigen expression across time or between methodologies. In other cases, the forward and reverse types may be completely concordant, but still inaccurate or contradictory with the patient’s historic blood type.
In this session we will focus on less commonly discussed causes of type discrepancies and blood grouping dilemmas. Using a case-based approach, we will explore three topics: B subgroups, acquired chimerism due to hematologic malignancy, and transfusion-related typing errors manifesting without mixed-field reactivity. For each entity, we will discuss the presentation, serologic and molecular laboratory evaluation (including ABO genotyping), pathophysiology, and transfusion management.
These entities may receive less ‘air time’ but are common enough to be seen in many transfusion services—probably more common than previously thought. They rarely receive a full immunohematologic investigation because they can be managed by provision of group O RBCs. However, their initial detection and evaluation involve considerable time and resources, so recognizing and managing these etiologies increases laboratory efficiency. Moreover, the availability of group O RBCs is increasingly constrained, so understanding the appropriate transfusion strategy for these cases is both critical for patient safety and facilitates judicious use of resources.