December 2022
Q. What is the appropriate way to measure or identify microcytosis or macrocytosis? Read answer.
Q. A six-year-old female with B-cell acute lymphoblastic leukemia and Rh-negative blood is being treated with myeloablative chemotherapy to achieve durable remission or as a bridge to stem cell transplantation, during which supportive transfusions will include repeated platelet transfusions over many weeks. Clinicians are concerned that the patient could become alloimmunized to the D antigen, which, in turn, could affect her ability to eventually bear children.
Apheresis platelets contain a small but finite amount of RBC contaminants, which are not usually quantitated. An optimal strategy to prevent anti-D alloimmunization is to use Rh-negative platelets, but they are often in short supply and cannot be ordered stat in a timely enough manner to ensure every platelet transfusion episode is Rh-negative. We considered using Rh immune globulin (RhIg). However, we recognize that commercial RhIg is designed to prevent D alloimmunization in the setting of obstetric fetal-maternal bleeding.
Is there an optimal dose for RhIg or suggested timing of administration to prevent anti-D alloimmunization in this setting? Read answer.
