“… 14 Previous studies showed that the prevalence of the Di a antigen presents racial variation; in a study with blood donors in Ecuador, a 25% prevalence of the Di a antigen and an alloimmunization frequency of 6.09% against this antigen were found and a similar alloimmunization frequency was found in a Brazilian population study, which reported an anti-Di a alloantibody prevalence of 6.0% in 12,904 multi-transfused patients. 15 , 16 The presence of the Di a antigen in blood donors poses a risk to the Di a negative-transfused patients.…”