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‐Pr^M

Abstract

A kappa-monotypic IgM high titer cold agglutinin reacting like anti-Pr at low, like anti-M at higher temperatures, is described. It recognizes tetra- and/or trisaccharides with immunodominant sialyl groups on glycophorins A, B, C like anti-Pr. Its affinity to the oligosaccharides is, however, approximately 10-fold increased when they are attached to the M-specific peptide backbone of glycophorin A. The antibody, termed anti-PrM, occurred in a blood group MN patient with chronic cold agglutinin disease and caused autoimmune hemolytic anemia.

Restriction in the repertoire of the immunoglobulin light chain subgroup in pathological cold agglutinins with anti‐Pr specificity

“…Anti‐Pr CAs may be further subdivided by their reactivity with chemically modified N ‐acetylneuraminic acid (Pr 1 , Pr 2 and Pr 3 ) and their reactivity with human (h) or dog (d) RBCs (Pr h and Pr d antigens) [11,13,14]. A certain subspecificity, termed anti‐Pr M , is characterized by serological reactivity, anti‐Pr‐like, at low temperatures (4 °C) and anti‐M‐like behaviour at higher temperatures [15]. The anti‐Pr M specificity reflects the close vicinity of Pr and M epitopes on the N‐terminal part of glycophorin A.…”

A new mechanism for immune destruction of red blood cells?

“…There are many publications concerning anti‐Pr in the literature; many of these were found in patients with CAS, but unfortunately, many of them concentrate on serologic and biochemical characteristics of the antibodies 10‐13 . Nevertheless, on reviewing the literature on association of anti‐Pr with HA, I found 27 reports with reasonable evidence for an associated HA 1‐3,7,9,14‐35 …”