Difficulties in identifying antibodies of high frequency antigens: A case report of anti-Holley antibody

Abstract

Abstract Introduction/Objective The Dombrock blood group system consists of the Dombrock (Do), Gregory (Gya), Holley (Hy), and Joseph (Joa) antigens, of which, the Gya, Hy, and Joa represent high prevalence antigens. Anti-Hy antibodies have been implicated in hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. Methods/Case Report We report a 22-year-old black female who presented with extensive burns following trauma. At admission the patient typed O, D-positive with a negative indirect antibody test (IAT). After receiving multiple units of red cells, plasma, and platelet products (>100 units total) the patient’s IAT, direct antiglobulin test (DAT) polyclonal, DAT IgG, and DAT C3 became seropositive (day 15 of ongoing transfusions). Elution was negative at all tested phases. An antibody rule-out panel was performed with pan-reactivity at polyethylene glycol (PEG)- anti-human globulin (AHG) (2+), Low ionic strength saline (LISS)-AHG (weak +), Ficin-AHG (2+), and negative with dithiothreitol (DTT)-PEG-AHG. Common DTT sensitive antigens were ruled out. Antigen typing displayed mixed field reactions secondary to transfusions. Hy-Jo(a-) confirmed cells were non-reactive at immediate spin and PEG-AHG. The patient was Dob positive, ruling out a null phenotype. Molecular testing could not be confirmed with serologic testing due to the extensive number of transfusions. Subsequent crossmatching demonstrated 1+ reactivity. The patient clinically tolerated the incompatible units. Her IAT resolved on day 29 of ongoing transfusions and remained negative throughout subsequent testing and transfusion. Results (if a Case Study enter NA) NA Conclusion Identification of antibodies to high frequency antigens is challenging due to the limitation of antigen negative sera in the setting of pan-reactive cells. Furthermore, blood contaminated with donor product limits the ability to perform serologic testing in the setting of mixed field reactivity. This case highlights the difficulty in identifying antibodies to high frequency antigens as well as the limitations in patient testing after extensive transfusion.