RH Genotype Matched RBC Transfusions

This is a Phase 1/2 trial in patients with Sickle Cell Disease requiring chronic red cell transfusions. RH genotyped donor units will be obtained from the New York Blood Center. Patients will be matched with donor units whose RH genotypes predict no foreign Rh protein exposure to the patient. This will provide red cell matching at a level above the current standard of care (serologic C, E, and K matching). Patients will receive RH matched red cells for the duration of their chronic transfusion therapy or up to three years, whichever is shorter. In the pilot phase, we have determined it is feasible to identify RH matched donor units for the patient's RH genotype for every scheduled transfusion. We will now continue to show feasibility as well as determine efficacy by monitoring Rh alloantibody formation.

For subjects with a history of stroke/recurrent transient ischemic attack or other indication who require tight control of Hb S, and RH genotyped blood is not available, standard of care serologic matched blood would be administered rather than delaying transfusion and risking higher Hb S level.

For all subjects, standard of care serologic matched blood would be administered rather than delaying transfusion beyond 7 days.

Inclusion criteria

• Subjects age >6 months
• Diagnosis of SCD, all genotypes
• Require a period of chronic red cell transfusion therapy
• Subject/parental/guardian permission (informed consent) and if appropriate, child assent

Exclusion criteria

• Rare RH genotype that would preclude identification of sufficient RBC units
• Antigen negative requirements due to alloimmunization that would preclude identification of sufficient RBC units
• Alloimmunized to D antigen
• Rh alloimmunized patients for whom providing RH genotype matched blood would expose the patient to an antigen that would not be consistent with standard of care and blood bank protocols
• Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures