Section IV. OTHER BLOOD GROUP SYSTEMS
a. In addition to the antigens described in the ABO and Rh blood group systems,
there are over 300 more that can be detected on human red blood cells by specific
antibodies. The more important of these additional groups, as far as practical blood
transfusion is concerned, are the Lewis, I, Kell, P, Duffy, Kidd, MNSs, and Lutheran.
Others, such as the only X-linked blood group Xga, contribute to the understanding of
human genetics, but are rarely clinically important.
b. Many antigens are not apparently related to any known genetic system.
Some, which occur on the red blood cells of almost all persons, are known as high-
incidence or "public" antigens. Others have a low incidence and are sometimes
referred to as "private" antigens. Some of these antigens are mentioned briefly in the
tables at the end of this lesson; more detailed information can be obtained from the
reference books listed.
2-30. LEWIS SYSTEM
a. The relationship of the Lewis genes, Le and le, to the ABO, Hh, and Se se
genes has been described. Although Lea and Leb antigens are not produced by red
blood cells, they are absorbed onto cell membranes as glyco-sphingolipids from the
plasma. Table 2-14 shows the Lewis red blood cell phenotypes.
IMPORTANT NOTE: The notation Le(a-b+) refers to a negative test for the antigen Lea
and a positive test for the antigen Leb. Likewise, the notation Le(a+b-) is used to
indicate a positive test for Lea and a negative test for Leb. Le(a-b-) means a negative
test for both Lea and Leb.
Table 2-14. Lewis red blood cell phenotypes.