Fatima Aldarweesh

Background A 54‐year‐old Hispanic OPos female with known history of anti‐Rh17 antibodies was diagnosed with Philadelphia‐Chromosome positive (Ph+) acute lymphoblastic leukemia (ALL). Rh17, also known as Hr 0 , is a high‐frequency antigen composed of several epitopes on the RhCE protein. Anti‐Rh17 antibodies can be made by individuals with missing or varied C/c, E/e antigens. Anti‐Rh17 antibodies are clinically significant given multiple case reports of hemolytic disease of the fetus and newborn (HDFN). Finding compatible units for patients with anti‐Rh17 can be particularly difficult given that only 1 in 100,000 people are Rh17 negative. Study Design and Methods Search for compatible units was conducted by the American Rare Donor Program (ARDP) with no leads. After chemotherapy induction and despite erythropoiesis stimulating agent administration, the patient's hemoglobin continued to trend down to a nadir of 2.8 g/dL. Here we report transfusion of incompatible pRBC to this patient with critically symptomatic anemia. HBOC‐201 (Hemopure) was obtained and administered under an emergency compassionate/expanded access designation from the Food and Drug Administration (FDA) under an emergency Investigational New Drug (IND) application. Results and Discussion Overall difficulties in this case included the challenge of finding compatible units, dilemma of transfusing incompatible units in a patient with severe anemia and obtaining alternatives to blood products. This case report demonstrates the successful use of HBOC‐21 in treating life‐threatening anemia.