Chronic Cold Haemagglutinin Disease Due to an Anti-M-Like Autoantibody

Abstract

A case of chronic cold haemagglutinin disease due to an IgM monoclonal (kappa) autoantibody with anti-M-like specificity is described in a patient with the MN phenotype. The autoantibody was present in very high titre and active at body temperature, but haemolysis was only mild. The direct antiglobulin test was positive due to C(3)d on the patient’s red cells, and the autoantibody was able to bind complement to normal MM and MN cells with a marked dosage effect.

A Human Monoclonal IgM k Cold Agglutinin Recognizing Oligosaccharides with Immunodominant Sialyl Groups Preferentially at the Blood Group M‐Specific Peptide Backbone of Glycophorins: Anti‐PrM

“…Several cases of auto-anti-M have been described [8,[24][25][26][27][28][29][30][31][32][33]. From the data available from the literature, the i,mpression emerges that the auto-anti-M cases reported can be divided into two groups (table VI).…”

Two Blood Group M Epitopes Disclosed by Monoclonal Antibodies

“…Thus, the cross reactivity between M and N as originally described by Landsteiner and Levine may not necessarily portend the presence of con taminating antibody specificities in xeno geneic typing reagents. Relevant observa tions have been made with human autolo gous monoclonal anti-M where 'anti-Mlike' has been employed for terminology [50,51]. Unfortunately, all examples of anti-M are 'anti-M-like' since anti-M devoid of crossreactivity has not been observed and, indeed, considering the biochemical similar ity between M and N, might not be ex pected.…”