The first example of anti-Doa, reactive with 64% of the
Caucasian population, was reported by Swanson et al. in 1965. It was not until 1972 that
Molthan et al. reported the antithetical antibody anti-Dob.
Thus, the Dombrock blood group system was defined and was estimated to be the fifth most
useful blood group marker in Caucasians. However, limited examples of both antibodies
greatly restricted broad investigations. Dombrock system antigens Doa
and Dob appear to be poor stimulis and most examples of both
antibodies rarely are found as a single specificity in a serum; and when detected, are
notorious for disappearing in vivo. Antibodies within this system have been
associated with weak to moderate transfusion reactions, but not with clinically defined
cases of hemolytic disease of the newborn.
The Dombrock system remained a simple two allele system until 1992, when Banks et
al. reported that the red cells of the rare Gy(a-) Hy(a-) Jo(a-) individuals were also
Do(a-b-). Consequently, these three high incidences blood factors were included within the
system. Interestingly, it had already been known that all Gy(a-) red cells lacked both Hya
and Joa antigens and that Hy(a-) red cells lacked Joa
antigens. Ironically, Swanson reported the first examples of both anti-Doa (in
1965) and anti-Gya (1967) but as anti-Dob
was, at that time, yet to be discovered any association with Doa
and Gya could not be deduced.
These blood group antigens are carried on a glycosylphosphatidylinositol (GPI)-linked
glycoprotein, but as of this date this system has not been associated with a defined