Incidence of Wra antigen and anti-Wra in a Spanish population.

Background: This study reports the incidence of Wr(a) antigen and anti-Wr(a) in Valencia, Spain.

Study Design And Methods: The incidence of the Wr(a) antigen in 110,000 healthy blood donors was estimated. Likewise, the incidence of anti-Wr(a) was analyzed in a population consisting of 730 healthy blood donors, 356 pregnant women, and 581 patients who received transfusions from the area of Valencia, Spain.