An acute haemolytic transfusion reaction caused by anti‐Wr^a

Abstract

The Wright (Wr(a)) antigen is found on the red blood cells of approximately 1 : 1000 Caucasians. Anti-Wr(a) has been reported to be present in 1 : 25 to 1 : 100 healthy blood donors and an even higher proportion of hospital patients. Incompatibility due to anti-Wr(a) might therefore be expected to occur in approximately 1 in 50,000 blood transfusions. Reports of haemolytic transfusion reactions (HTR) and haemolytic disease of the newborn due to anti-Wr(a) are, however, rare. We report an acute HTR due to anti-Wr(a) in a 58-year-old man with myelodysplastic syndrome associated with rigors, shortness of breath and a significant rise in serum bilirubin from 16 micromol L(-1) pretransfusion to 110 micromol L(-1) immediately afterwards. This was accompanied by the appearance of bilirubin and urobilinogen in his urine and a fall in haemoglobin of nearly 2 g dL(-1) following the transfusion. Anti-Wr(a) was the only antibody implicated. When tested against the recipients plasma, Wr(a+) panel cells and the transfused unit responsible for the reaction were 2-3+ by indirect antiglobulin test (IAT) and the donation typed as Wr(a+). The recipient had the common Wr(a-) phenotype. The reaction resulted in the patient being admitted to hospital for 2 days. The increasing use of electronic issue may result in more frequent reports of reactions due to anti-Wr(a) using current screening cells.

Fatal Acute Hemolytic Transfusion Reaction due to Anti-Wra

“…As a consequence, subsequent laboratory investigation to exclude or prove an HTR was not undertaken. The addition of Wr a to the list of antigens present on the RBCs used for antibody detection would increase the cost and time to unit release [5,21]. But presumably, detecting the incompatibility could in this specific case have prevented the fatal course.…”

“…Some acquired allo-antibodies can less frequently cause an acute HTR, such as antibodies against antigens from the Rh, Kell, Kidd, and Duffy blood group system. Only a few cases have been described [5,7,8,9,10,11] in which an acute HTR was due to anti-Wr a , with one fatal case which was also caused by other factors than the HTR [8]. According to the Serious Hazards of Transfusion Steering Group, HTRs due to anti-Wr a are mild and are mostly unnoticed [13].…”

“…Considering the overall prevalence of anti-Wr a (3%) and the frequency of Wr a antigen in blood donors (0.1%) [1,2], the chance for a patient to receive a Wr a -mismatched transfusion is 1:16,000 per cell unit [16]. The described HTRs associated with anti-Wr a are likely mild, and because of its relative rareness it was concluded that the addition of Wr a to the list of antigens present on the antibody screening cells would increase the costs and was not necessary [5]. …”

“…Anti-Wr a is capable of causing severe hemolytic transfusion reactions (HTRs) [5] as well as hemolytic disease of the newborn [6], but because of the low frequency of Wr a antigen severe reactions are relatively uncommon. Only 6 cases of hemolytic transfusion reactions have been described [5,7,8,9,10,11]. In the Serious Hazards of Transfusion (SHOT) Steering Group reports from 2012 to 2016, 11 cases of anti-Wr a causing HTR have been reported, one of which resulted in death of the patient [12] whilst the other cases had minor morbidity [13].…”

“…The prevalence of anti-Wr a is ranging from 1:56 in healthy blood donors [3] to 5.8% in a range of individuals (blood donors, pregnant women, and hospitalized patients) [4]. Anti-Wr a is capable of causing severe hemolytic transfusion reactions (HTRs) [5] as well as hemolytic disease of the newborn [6], but because of the low frequency of Wr a antigen severe reactions are relatively uncommon. Only 6 cases of hemolytic transfusion reactions have been described [5,7,8,9,10,11].…”