Background/Case Studies: Anti-AnWj (Anton) is a rare antibody targeting a high-frequency red blood cell antigen and has previously been associated with two reported cases of hemolytic transfusion reactions. This case study adds to the limited literature by documenting the identification of anti-AnWj antibodies in a patient who experienced multiple febrile, nonhemolytic transfusion reactions. In this instance, the patient’s symptoms were not communicated to the immunohematology reference laboratory (IRL), highlighting the challenges of timely recognition and diagnosis of this rare antibody specificity.
Study
Design/Methods: A retrospective analysis was conducted on a 43-year-old male diagnosed with diffuse large B-cell lymphoma of the stomach, acute immune thrombocytopenic purpura (ITP), and anemia of chronic disease. The study covered a 128-day period, during which a series of clinical interventions were implemented. Key events included initial immunohematology testing, the occurrence of transfusion reactions, adjustments to transfusion protocols, and the eventual identification of the causative antibody.
Results/Findings: On Day 1, the IRL identified a warm autoantibody with no underlying alloantibodies. The patient reacted after receiving one unit of CPD/AS1 pRBCs. Following this, pretreatment with acetaminophen and antihistamines was initiated. On Day 3, a second febrile, nonhemolytic transfusion reaction occurred after transfusion of CP2D/AS3 apheresis RBCs. Day 4 testing again showed a warm autoantibody with no alloantibodies. On Day 22, orders were placed to split pRBC units, administer 100 mg hydrocortisone, and transfuse slowly. By Day 108, pretreatment was escalated to include IV Benadryl, Solu-Medrol, and IVIG. On Day 118, anti-AnWj antibodies were identified after the IRL was notified for the first time of the patient’s transfusion reactions, prompting testing against a high-frequency antigen panel. Conclusions: This case underscores the importance of thorough and ongoing immunohematological investigations in patients experiencing repeated transfusion reactions. The delayed identification of anti-AnWj highlights the need for improved communication between clinical teams and the IRL. Only nine reports of anti-AnWj have been published since it was first documented in 1972; two of these cases involved transfusion reactions. Early recognition of rare antibodies is crucial for proper patient management, potentially requiring specialized transfusion support.
