Immunological Identification of the Pathological Cold Auto-Antibodies of Acquired Haemolytic Anaemia as β2-M Globulin.

Cold antibodies were separated from the sera of six patients suffering from the cold-haemagglutinin syndrome and from one patient with acquired haemolytic anaemia secondayr to lymphosarcoma by dissociation of the specific antigen-antibody complexes. The eluted antibodies were studied (a) by immuno-electrophoresis along with the parent sera against horse anti-human serum and (b) by double diffusion in agar gel along with electrophoretically separated ‘γ₁ globulin’† against anti-19S ‘γ-globulin’ rabbit sera. The protein forming the cold antibody was localized in the β₂-M position on immuno-electrophoresis in each instance. It was found by double diffusion in agar gel to be immunologically identical with the protein forming the abnormal ‘γ_l-globulin’ electrophoretic peak in the parent serum. The results of these experiments indicate that the cold antibodies derived from patients with the cold-antibody type of acquired haemolytic anaemia are macro-molecular globulins. [ABSTRACT FROM AUTHOR]