The difficult transfusion management of a woman positive for anti-RH17 antibodies, a red blood cell (RBC) antigen known for its association with hemolytic disease of the fetus and newborn (HDFN), has been recently published on Transfusion.
The RBCs are characterized by having multiple molecules (antigens) on their surface; the presence or absence of certain antigens in the RBCs of an individual determines his blood type.
For example, a person whose RBCs express the A antigen but no RhD antigen would be classified as A negative. If this person received a transfusion of A-positive blood, the immune system would recognize the RhD antigen as foreign and develop an immune reaction against it. This immune response with antibody creation is responsible for HDFN as well as transfusion reactions.
Only one in every 100.000 persons is Rh17 negative, which makes finding compatible blood for transfusion a clinical challenge.
“The anti-Rh17 antibody has been reported in a variety of populations, and there have been case reports of hemolytic disease of the fetus and newborn (HDFN) ranging from mild to severe,” the authors wrote.
The case involved a 54-year-old woman with a recent diagnosis of acute lymphoblastic leukemia (ALL) and a history of 5 pregnancies complicated with HDFN due to anti-Rh17 antibodies.
At the moment of admission, the patient had severe anemia that required a blood transfusion; due to the lack of compatible blood, she was approved to receive experimental treatment with HBOC-201.
HBOC-201 is a hemoglobin-based oxygen carrier, a semisynthetic system that imitates the oxygen-transporting functions of red blood cells, distributing oxygen throughout the body. In the United States, it is only available through FDA approval in specific cases due to its possible adverse effects, including myocardial infarction and hypertension.
Before the HBOC-201 was started, the patient worsened, and the attending physicians transfused incompatible blood, leading to a transfusion reaction and scarce clinical improvement.HBOC-201 was started three days later with significant improvement; the patient was discharged soon after.
“Overall, this patient’s clinical improvement and recovery seems to support the use of HBOC-201 in patients with life-threatening anemia who cannot receive conventional blood products,” the authors concluded.
