Studies on Anti-Mi^a and the MiIII Complex

Abstract

Some Ms/Ms Milll red cells react weakly with rabbit anti-N but not with human anti-N sera. Specificities of different anti-Mi^a within the Miltenberger complex have been defined by absorbtion studies with different Mi classes.

Serological Activity of Low Frequency Antigens of the MNSs System and Reappraisal of the Miltenberger Complex

“…There are no biochemical data to show that Mi(a+) cells of Mi classes I, II, III, IV, VI and pos sibly V [14] have a shared abnormal a-or 8-component. Anti-Mi3 sera are thought to be polyspecific with both separable and cross-reactive antibodies [7,8], and this het erogeneity has been confirmed by showing that some determinants are trypsin sensitive whilst others are not. By considering the determinants rather than the 'type sera', the complex is simplified (table V).…”

MNS Blood Group System

“…GP.Mur and GP.Bun are always inherited with s. In people of European origin GP.Mur may be inherited with Ns or with Ms , the former being more frequent than the latter [289] . GP.Mur and GP.Bun phenotypes are associated with an elevated expression of ' N ' , the trypsin -resistant N antigen carried on GPB [129,226,289,297,317,318] . GP.Bun is generally inherited with Ms [297] .…”

“…Anti -Mur is a fairly common separable component of anti -' Mi a ' sera, though it also occurs alone [289,317,318,330,331] . Antibodies to GP.Mur red cells (probably mainly anti -Mur, but often called anti -' Mi a ' ) have been responsible for immediate and delayed HTRs [332,333] and severe HDFN [333 -335] (reviewed in [336] ).…”

“…Anti -Vw occurs in mixtures of antibodies to low frequency MNS antigens (as a component of anti -' Mi a ' ) [317] or by itself [288,296] , where it has been responsible for severe HDFN [351,355 -357] and for severe, acute HTRs [358,359] (although this is disputed in one case [360] ) (reviewed in [336] ). Anti -Vw is not uncommon in the sera of healthy individuals, with about 1% of normal sera containing anti -Vw [16,291,293] .…”

“…Although anti -Mi a was the antibody that originally defi ned the phenotypes of the Miltenberger subsystem, it was subsequently considered to represent mixtures of antibodies to low frequency antigens, especially anti -Vw, -Mur, -Hut, and -MUT [120,285,317] . Production of two murine monoclonal anti -Mi a , however, demonstrated that anti -Mi a could exist as a separate entity [343,344] .…”