Guidance for transfusion management in patients receiving magrolimab therapy (anti-CD47 monoclonal antibody).

Magrolimab (Hu5F9-G4) is a first-in-class anti-CD47 IgG4 monoclonal antibody, with potential applications in several malignancies including myelodysplastic syndrome. CD47 blockade in malignancy has been shown to promote antitumour effects. However, the ubiquity of CD47 on red blood cells can result in interference in pretransfusion immunohaematology investigations and hinder timely provision of red blood cell units, with potential to mask clinically significant alloantibodies.

Cold reacting anti-M causing delayed hemolytic disease of the newborn.

Background: Hemolytic disease of the fetus and newborn (HDFN) is due to passively transferred maternal antibodies directed against fetal red blood cell (RBC) antigens and can lead to severe morbidity and mortality. Anti-M is usually a naturally occurring antibody of low clinical significance, although occasionally severe cases of HDFN are seen.

Case Reports: Two M+ sisters are presented, each developing hemolysis during the first 2 weeks of life due to maternal anti-M, resulting in severe anemia and requiring blood transfusion.