HL-A, ABO, and Rh antigens, as well as different kinds of humoral and
cell-mediated immune responses, were determined in 133 volunteers. These were selected
from 463 subjects immunized with Rh(o)(D), or staphylococcus, or pertussis antigens according
to their low and high immune responsiveness. HL-A and blood group antigens
were correlated by a computer program to categorized immune parameters (low, medium,
high values). The latter were correlated with each other. The only notable association of
the immune parameters with HL-A antigens was found between HL-A 3 and 7 and
spontaneous lymphocytotoxic activity in mouse fibroblast monolayer. A striking correlation
was, however, found between Rh antigens and a number of antibacterial antibody
levels and parameters of cell-mediated immune responses. These correlations indicate
that Rh(o)(D)-positive subjects had rather high ‘natural’ antibody levels and PHA-reactive
lymphocytes. The latter were stimulated, however, only with high doses of PHA (PHA
hyposensitivity) and they lacked spontaneous lymphocytotoxic activity. A reverse correlation
was found in Rh(o)(D)-negative subjects, the ability to produce anti-Rh(o)(D) antibodies
being negatively associated with the level of some antibacterial antibodies. Natural antibody,
immunoglobulin level and lymphocyte activity were significantly lower in males.
Correlation was seldom found between categorized values of the individual immune
parameters such as antibacterial antibodies, immunoglobulins, complement, and cellmediated
immunity factors. Negative correlations were obtained between PHA hyposensitivity
and a low antibacterial antibody level, and a positive one between IgA, complement
level and lymphocyte stimulation. These results the Rh system may be associated
with a gene or genes involved in immune response regulation.