McLeod Syndrome: A Perspective from Japanese Blood Centers.

McLeod phenotype is one of the rare blood cell types, defined as those that occur at a frequency of 1:1,000 or less. We have screened donors for rare cells since 1987 using mouse monoclonal antibodies (MAbs). In the western regions of Japan a total of 16,160,714 donor red cells were screened using mouse anti-Kell MAbs (anti-k, anti-Ku and anti-K14) during 1987-2005. We found 182 blood cells with McLeod phenotype or Kmod and 286 with Ko. To identify McLeod phenotype, we examine the expression level of Kell antigens by flow cytometry, cell morphology (acanthocytes) by scanning electron microscopy, red cells of family members and the XK gene. As a result, we identified three donors with McLeod phenotype (two subsequently developed McLeod syndrome) and two with McLeod-like phenotype. Nine donors are now registered as McLeod phenotype in all Japan. [ABSTRACT FROM AUTHOR]