Administering RhD-positive packed red blood cell concentrates (PRBCCs) to selected RhD-negative patients during blood supply shortages has been linked to saving a significant number of RhD-negative units, according to a study recently published in Transfusion.
What is HDFN?
Hemolytic disease of the fetus and newborn (HDFN) is an immune-mediated red blood cell disorder that occurs when a baby’s RBCs break down quickly, which is called hemolysis. HDFN is caused by a mismatch between a mother’s and her baby’s blood type (A, B, AB, or O) or Rhesus (RhRh factor A protein or antigen found on red blood cells. When an Rh-negative mother carries an Rh-positive fetus, her immune system may make antibodies that attack the fetus' red blood cells.) factor (Rh-positiveRh-Positive A blood type trait that means your red blood cells have the Rh(D) antigen. or Rh-negativeRh-Negative A blood type trait that means your red blood cells lack the Rh(D) antigen.) during pregnancy.
The findings show that this strategy helped conserve valuable RhD-negative blood for those at greater risk of sensitizationSensitization The process by which a mother’s immune system becomes “primed” to recognize and attack fetal red blood cells carrying incompatible antigens., such as women who could become pregnant in the future.
The study authors stated that to their knowledge, this is the first study reporting a high proportion of evanescence, or levels so low they are undetectable, of anti-D.
Read more about HDFN testing and diagnosis
Realizing that studies have shown up to 50% of RhD-negative individuals develop anti-D following an RhD-positive blood transfusion, the investigators sought to evaluate the rate of anti-D alloimmunizationAlloimmunization When a person’s immune system develops antibodies against foreign antigens from the same species—such as when an Rh-negative mother’s body forms antibodies against her baby’s Rh-positive red blood cells. by utilizing this restriction policy in their patient population.
A total of 607 RhD-negative patients who received RhD-positive PRBCCs between Sept. 1, 2006, and Dec. 31, 2011, were identified. Following transfusion, antibodyAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens. screens were available for 401 patients. Of these individuals, anti-D was detected post-transfusion in 76 patients. In fact, in 15 of the 76 individuals, anti-D became evanescent (of short duration) and was no longer detected in the follow-up.
In the current study, the percentage of anti-D immunization in RhD-negative individuals who received RhD-positive PRBCCs is in line with the results of other similar reports.
“We saved 1926 RhD[-]negative PRBCCs during the study period of 64 months by transfusing selected RhD[-]negative patients with RhD[-]positive PRBCCs,” the authors noted. “With this strategy, we had more RhD[-]negative units [available for] RhD[-]negative patients [who] should not receive RhD[-]positive PRBCCs regarding future pregnancies and the risk.”
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