Rare Anti-AnWj Antibody Case Highlights Challenges in Life-Saving Blood Transfusions
A new study describes a very rare medical case and explains why treating patients with unusual antibodies in their blood can be extremely difficult.
It concerns a 75-year-old man who had several serious conditions (heart problems and a blood-clotting disorder). He was admitted to the hospital twice due to severe bleeding and severe anemia (very low hemoglobin), which meant he required a blood transfusion.
The authors, Ethar Al-Husseinawi, Morgan Heitt, Ty Moore, Sumalatha Muthineni, Gina Folk, Amitava Dasgupta, and Zhan Ye, described this case in detail in their paper titled “Rare anti-AnWj autoantibody in a 75-year-old male: Case report and review of the literature.”
An extremely rare antibody called anti-AnWj
The problem was that he was found to have an extremely rare antibody called anti-AnWj. AnWj is an antigen on the surface of red blood cells that is present in more than 99% of people. If a person has an antibody against this antigen, a transfusion can be dangerous because the immune system may attack the transfused red blood cells. “A high-prevalence antigen, the AnWj or Anton (ISBT 901009), previously also known as Wj, was first identified in 1972….This case presents clinical challenges when a rare antibody, such as anti-AnWj, is encountered in a critically ill patient requiring transfusion,” the authors wrote.
“Xu et al. reported a case of acute hemolytic transfusion reaction due to anti-AnWj in a patient with aplastic anemia requiring allogeneic stem cell transplantation. The authors attempted to suppress production of the anti-AnWj with four cycles of rituximab, oral prednisone, and plasma exchange. Unfortunately, none of these therapies proved successful. Although the antibody titer decreased from 128 to 2 with plasma exchange, even at the low titer, the patient demonstrated signs and symptoms of hemolysis after transfusion of 100 mL of random-donor RBCs, and the DAT remained positive throughout. The patient remained transfusion dependent until her death from complications of pneumonia in the posttransplant period.” Anti-AnWj case report (Al-Husseinawi et al.)
In this case, an additional problem was that no compatible blood (AnWj-negative) was available, because such blood is extremely rare. Doctors had to decide whether to risk giving incompatible blood or to withhold transfusion from a patient whose life was threatened by anemia. After consulting multiple specialists, they decided to proceed with a transfusion of the “least incompatible” blood, with careful monitoring.
Interestingly, the patient did not experience any harmful reaction after the transfusion. “Fortunately, our patient did not experience a hemolytic transfusion reaction, likely reflecting the low titer or the autoantibody nature of anti-AnWj,” they explained.
A major challenge in transfusion medicine
The study also compares this case with previous ones. In some other cases, anti-AnWj has caused serious transfusion reactions, even death. However, such cases are very rare. Only a few reactions caused by this antibody have been reported so far. Such cases can be a major challenge in transfusion medicine. When compatible blood is not available, doctors must carefully assess the risk: what is more dangerous, refusing transfusion or giving potentially incompatible blood. “We observed no transfusion reaction in our patient with weak auto-anti-AnWj antibody, and to our knowledge is the first report of no post-transfusion hemolysis in a patient with genetically confirmed auto-anti-AnWj antibody,” the authors concluded.
