The Lutheran Blood Groups: A Progress Report with Observations on the Development of the Antigens and Characteristics of the Antibodies

Scoring titrations with anti‐Lua on 81 members of the families of seven Lu(a+b—) propositi did not produce any evidence for the presence of Lu genes. In the Lu(a+b+) heterozygotes the Lua antigen was only weakly expressed at birth increasing progressively during the first 15 years. The red cells of Lu(a+b—) children gave scores comparable to those of adults. The reactions of Lu(a—b+) cord cells were somewhat weaker than those of adults but the red cells of Lu(a+b+) infants reacted very weakly with anti‐Lua. Four infants born to mothers with anti‐Lub had no evidence of hemolytic disease due to this antibody. Serologic, immunochemical and ultrafiltration studies suggest that the examples of anti‐Lub studied are mainly IgA. These observations can explain why no unequivocal examples of hemolytic disease of the newborn due to anti‐Lub have been encountered.