rh'(C) but negative for Rho(D) can develop an antibody apparently directed against
Rho(D). Such an antibody, in most cases, is really anti-rhG. Rh-negative persons rarely
receive Rho(D)-containing blood, but, if exposed through pregnancy or transfusion to
Rho(D)-positive, rh'(C)-negative cells, they could form antibody with apparent anti-rh'C)
activity. Other cross-reactions may occur between rh'(C) and rh"(E), and between rh'(C)
and hr"(e).
e. "Variant" Antigens.
(1) There must be innumerable subtle differences in composition among
various Rh gene products. Although red cells from most people give straightforward
reactions with common antibodies, those from some give atypical reactions, and others
stimulate the production of antibodies that do not react with red cells of common Rh
phenotypes. It has been convenient to consider C and c, and E and e, as antithetical
activities at specific surface sites. This scheme can be expanded to include alternative
antigenic activities that seem to reside at the same site, but are determined by genes
coding for activity distinct from the common Rh determinants.
(2) Atypical activity at the e site is fairly common in Blacks. Several distinct
patterns have been identified, such as hrs- and hrb-. Diminished c and markedly
diminished e activity are among the features of products of the RN gene, which also
determines a low─frequency antigen, Rh32. Among Whites, a weakened e antigen is
among the products of genes that determine the Rh33 (Ro Har) and the Bea (Berrens)
antigens.
(3) Antigens that behave on most occasions as if they had an antithetical
relationship to C/c or E/e have been found, mainly in Whites. The most common is Cw,
which occurs in 2 Table 2-12 lists many of the separate antigens that have been found to
belong to the Rh system and have contributed to the advancing complexity of the
system and its nomenclature.
2-22. THE LANDSTEINER and WIENER ( PROBLEM
a. As work in the Rh system progressed, evidence accumulated that the antigen
identified by the rabbit antiserum of Landsteiner and Wiener (LW) was not, after all, the same
as the antigen present on 85 percent of human blood cells. Similarities exist, but numerous
absorption, elution, agglutination, and immunization studies have demonstrated two
different activities. The antigens identified on rhesus monkey cells are present on
nearly all human cells, both Rh-positive and Rh-negative. Adult Rh-negative cells have
rather weak activity. Cord blood cells, both Rh-positive and Rh-negative, have
abundant activity. Since the term Rh was so firmly entrenched, Levine proposed that
the newly characterized activity universal in rhesus monkeys and extremely common in
human subjects be called LW, in honor of Landsteiner and Wiener. Rare persons exist
whose cells have normal Rh antigens, either with or without Rho(D), but whose red cells
have so little LW activity that they are able to form allo-anti-LW.
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