Alloimmunization in two multitransfused patient populations.

A retrospective study was undertaken to determine the frequency of alloimmunization in two multitransfused patient populations. Three hundred eighteen unselected patients whose transfusion records were available were studied. One hundred fifty-seven patients had sickle cell disease (SCD) and 161 had thalassemia. Forty-four antibodies were detected in 23 of the 99 transfused SCD patients. The predominate antibodies were in the Rh group: seventeen were anti-rh"(E), eight were anti-rh'(C), and four were anti-rh'w(Cw). Of the remaining antibodies, five were anti-Kell, three were anti-Jka, two were anti-Jkb, three were anti-Fya, one was anti-Bga, and one was anti-S. In the thalassemic patients, six antibodies were detected in 4 of the 39 transfused patients. Of these, there were two anti-Kell and one anti-Rho (D), anti-rh'(C), anti-rh'w(Cw), and anti-Fya each. Although the SCD patients were more likely to have been transfused at the parent institution than were the thalassemic patients (69% vs. 24%, p less than 0.05), the frequencies of alloimmunized patients, the total number of antibodies, and the number of Rh antibodies did not differ significantly (p greater than 0.05) for transfused patients in the two populations.