g. Anti-M and N, like anti-I and P1, are of little clinical importance. There have
only been one or two reports of hemolytic transfusion reactions and hemolytic disease
of the newborn caused by MN antibodies since their discovery in 1927. These rare
examples of clinically significant anti-M and -N reacted up to 37C "in vitro".
h. A high incidence of anti-N-like antibodies has been encountered in patients
who have undergone renal dialysis. These have occurred in N-positive and N-negative
individuals. Failure of kidney grafts has been attributed to such cold agglutinins when a
cold donor kidney was transplanted.
i. Anti-S, anti-s, and anti-U are occasionally found in human serum, usually as
immune antibodies. They have each caused hemolytic transfusion reactions and
hemolytic disease of the newborn.
2-37. LUTHERAN BLOOD GROUP SYSTEM
a. Using anti-Lua and anti-Lub, four phenotypes have been described (see
Table 2-29. Phenotypes and frequencies of the Lutheran system in Whites.
NOTE: Insufficient data for reliable calculation of frequencies in Blacks.
b. Many high-incidence antigens are associated with the Lutheran system (for example,
Lu4, 5, 6, 7, 8, 11, 12, 13, 15). Any one of these may be missing from the cells of a rare
person whose other Lutheran antigens appear normal, thus rendering that individual
capable of forming the antibody directed against the high-incidence antigen that his
cells lack. Lu(a-b-) cells lack all these other high-incidence Lutheran system antigens
and the low-incidence antigens (for example, Lu9, 10, and 14) that have been discovered so far.