Detection of multiple passively acquired alloantibodies following infusions of IV Rh immune globulin

Abstract

Plasma samples from D+ patients with ITP treated with IV RhIG regularly contained anti-D and multiple other passively acquired Rh, Duffy, or Kidd system alloantibodies. Postinfusion RBC samples all had positive DAT results with eluates containing anti-D and multiple other Rh, Duffy, or Kidd system antibodies. The consistent detection of multiple passively acquired alloantibodies after IV RhIG, in contrast to the detection of anti-D only after IM RhIG, reflects the immediate effect of the entire (bolus) dose of RhIG by the IV route, the dose for treating ITP that is approximately 10 times the dose for Rh immunoprophylaxis, and the expected serologic incompatibility with recipients' D+ RBCs.