title: Incidence of Wra antigen and anti-Wra in a Spanish population.
abstract: BACKGROUND
  This study reports the incidence of Wr(a) antigen and anti-Wr(a) in Valencia, Spain.
  
  
  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.
  
  
  RESULTS
  The incidence of Wr(a) antigen was 1 in 785. Overall, anti-Wr(a) was found in 59 samples: 20 healthy blood donors (1/37), 18 pregnant women (1/20), and 21 patients who received transfusions (1/28). The most frequent immunoglobulin class of anti-Wr(a) in healthy blood donors was immunoglobulin M, either alone (8 cases) or plus immunoglobulin G (IgG; 8 cases); the IgG1 and IgG3 were the IgG subclasses most frequently detected in pregnant women (12 cases) and in patients who received transfusions (12 cases). Only 51 percent of the anti-Wr(a) appeared to have the potential to be clinically significant.
  
  
  CONCLUSIONS
  These data show that the incidence of Wr(a) antigen and anti-Wr(a) among the population from Valencia is similar to that reported in other European areas and suggest that the development of anti-Wr(a) is facilitated by the presence of a hyperactive immune system. The clinical relevance of anti-Wr(a) is limited, however.
authors.affiliation: Department of Hematology, University Hospital La Fe, Valencia, Spain. arriaga_fra@gva.es
authors.forename: Francisco
authors.initials: F
authors.lastname: Arriaga
authors.forename: Francisco
authors.initials: F
authors.lastname: Llopis
authors.forename: Javier
authors.initials: J
authors.lastname: de la Rubia
authors.forename: Nelly
authors.initials: N
authors.lastname: Carpio
authors.forename: Jesús
authors.initials: J
authors.lastname: Moscardó
authors.forename: María L
authors.initials: ML
authors.lastname: Marty
mesh_terms: D001789:Blood Group Antigens / Q000097:blood*; D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood / Q000145:classification; D007518:Isoantibodies / Q000097:blood*; D013030:Spain
chemical_list: D001789:Blood Group Antigens; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007518:Isoantibodies