Association of ABO blood groups and vitiligo

ABO blood group frequencies of 1000 vitiligo patients were studied and compared with those of blood donors and local population. The relative risk of O was significantly reduced in patients in comparison with blood donors but not with local population. This can possibly be explained by the well-known preference of O group donors in the blood bank. On a review of other studies it was felt that there may not be any real association of ABO blood groups with vitiligo.