Development of Anti-e after Platelet Concentrate Transfusion

Abstract

Platelet concentrates (PC) is prepared from donated whole blood units by centrifugation and subsequent pooling of 4-6 units Advancing Transfusion and Cellular Therapies Worldwide Advancing Transfusion and Cellular Therapies Worldwide. Thus, PC may contain a small amount of donor RBC. We report a case of a 60 year-old male patient with past medical history of coronary artery disease, who presented to our emergency department with shortness of breath. Previous medical history indicated a recent admission, one month prior, to another local hospital for shock and respiratory failure. Type and screen (T/S) done at that time reveal an O+ blood type with negative antibody screen. During that admission, the patient received only 5 doses of PC (2-group O+, 2-group O-, and 1-group A-). He denied any other recent blood product transfusions at any other facility. Our current T/S, and before any transfusions, showed a positive antibody screen. A panel for antibody identification was performed. The antibody reacted with 9 out of 10 reagent cells. The reactivity was predominately at room temperature and 37°C phases indicating an IgM class antibody. Some reactivity was also seen at AHG (anti-human globulin) phase indicating an IgG class antibody. The auto control was negative. Testing additional cells revealed an anti-e specificity. Patient’s “e” antigen typing was performed and found to be negative indicating that this is a true allo-antibody. Since anti-e antibody predominantly exists as an IgG immunoglobulin class antibody, the presence of IgM class reactivity suggests that this may be a newly developed antibody. This case illustrates that antibodies to RBC antigens can develop after platelet transfusion.