Anti‐Wj: an autoantibody that defines a high‐incidence antigen modified by the In(Lu) gene

Abstract
An IgG autoantibody, named anti‐Wj, reacts with all random and most selected red cell samples. It does not agglutinate cells of Lu(a‐b‐) type caused by the In(Lu) dominant inhibitor gene, but cells of recessive Lu(a‐b‐) type are reactive. These data establish that synthesis of the Wj antigen is suppressed by the In(Lu) gene, but it is not a part of the Lutheran blood group system. The Wj antigen is not well developed on fetal red cells. This example of auto anti‐Wj is a non‐complement‐binding IgGI protein that did not appear to cause accelerated in vivo destruction of the patient's red cells.