RhD negative women transfused RhD positive blood: Alloimmunization prophylaxis protocol and experiences

Abstract Introduction/Objective Preventing allomiunization from D-mismatched transfusions, i.e., transfusion RhD positive (RhD+) red blood cells (RBC) to an RhD negative (RhD–) individual, is not well established. We describe our hospital protocol and experiences managing RhD– young women who received emergency release D-mismatched transfusions. Methods/Case Report The pathologists evaluate all patients who received D-mismatched blood transfusions. The inclusion criteria for alloimmunization prophylaxis protocol include: RhD– females; <50 years old; No current or historical Anti-D; and received ≥1 unit of RhD+ blood. The prophylaxis protocol depends on the RBC volume (RBCV) transfused. Patients who receive RBCV <20% of their total blood volume (TBV) are eligible to receive high dose RhIg, calculated based on the volume transfused. Those who received RBCV ≥20% of TBV would be eligible for red cell exchange (RBCX) followed by RhIg. Results (if a Case Study enter NA) Since 2016, four eligible patients received RhIg prophylaxis protocol and none met the criteria for RBCX. All the patients started the prophylaxis protocol within 24 hours of transfusion and completed it within 72 hours. One patient developed post treatment hemolysis and significant drop in hemoglobin requiring blood transfusion. Passive anti-D post treatment was confirmed in three patients, and one had passive anti C. Three of the four patients had follow up antibody screens >6 months post treatment that were negative for RhD alloimmunization. Conclusion Our therapeutic plan, the first well established protocol, involves identifying eligible patients based on set criteria and protocols. Our experience demonstrates that this protocol is effective in reducing/preventing RhD alloimmunization.