REPORT ON TWO CASES HAVING ANTI-Wr^a ANTIBODY WITH SPECIAL REFERENCE TO THE BACKGROUND OF ANTI-Wr^a PRODUCTION

Abstract

Here reported are two patients having anti-Wr^a antibody, which have been uncommon in Japan. Further, we have found 38 such cases so far reported in our country. The 40 cases in all have been examined on their backgrounds which might be related to the anti-Wr^a production.
1) Case report: Case No. 1: A 78-year-old female, complaining of dizziness and palpitation, was found to have autoimmune hemolytic anemia.
She had never received blood transfusion. Her blood group was B, CcDEe, Wr (a-). Direct antiglobulin test (DAT) using anti-IgG was positive, and the eluate from RBC reacted against all of the panel red cells, showing presence of panreactive warm-type anti-RBC autoantibody. The patient's serum, even after its autoantibody was absorbed by her own RBC, still showed presence of anti-Wr^a.
Case No. 2: A 68-year-old male had been suffering from the myelodysplastic syndrome, which thereafter transformed to myelocytic leukemia.
His blood group was A, Rh (D)-positive. The screening test for unexpected anti-RBC antibodies was initially negative, which turned to positive along with DAT after frequent blood transfusions. Further laboratory tests detected panreactive warm-type anti-RBC autoantibody in the eluate from the patient's RBC as well as alloimmunized anti-E and anti-Wr^a in his serum.
2) Results obtained by the survey on the anti-Wr^a in Japan: In the majority of the 40 cases with anti-Wr^a in Japan, including our above-mentioned two, the anti-Wr^a seemed to be a natural antibody, while, in 3 of them, anti-Wr^a was coexistent with the warm-type anti-RBC autoantibody. Besides, other 2 cases seemed to be drug-induced. These findings raise interests in the etiology of anti-Wr^a. However, the anti-Wr^a itself may be clinically innocent here in Japan, because any individuals having the blood group antigen Wr^a have not yet been found among Japanese. In addition, if Wr^a-positive RBC will be hereafter more commonly included in panel red cells for screening unexpected anti-RBC antibody, anti-Wr^a may, probably, be more frequently detected in Japan.