Haematologia 6. (1972)
1972 / 3. szám - Puskás, É. - Ferencz, É. G. - Szelényi, J. G. - Hasitz, M. - Medgyesi, G. A. - Gergely, J.: Non-specific attachment of IgG to erythrocytes
Haematologia 6 (3), pp. 275 — 2S3 (1972) Non-Specific Attachment of IgG to Erythrocytes Éva Puskás, Éva G. Ferencz, Judith G. Szelényi, Mária Hasitz, G. A. Medgyesi, J. Gergely National Institute of Haematology and Blood Transfusion, Budapest, Hungary (Received May 23, 1971) The non-homogeneous character of the IgG red blood cell interaction has been shown. At least two types of IgG-binding were found; a looser, Fc-dependent one, and a firm one. The presence of IgG-membrane complexes in the eluate of erythrocytes, and that of IgG in erythrocyte membrane preparations and the induction of antibodies with anti-IgG activity by immunization with erythrocyte membrane have proved the intensive interaction of IgG molecules with the red blood cell membrane. The altered antigenicity of the IgG molecules fixed to the erythrocyte membrane points to structural changes in the IgG as a consequence of the interaction. The non-specific or “non-antibody type” binding of IgG to the red blood cell surface is a well-known phenomenon [1 — 11]. The type of this interaction, however, is not characterized equivocally. Two types of IgG fixation were found by Pirofsky et al. [2]: a looser and a firmer one which differ in their release and exchange ratios. The non-specific interaction between red blood cells and IgG molecules is considerably influenced by the ionic strength of the medium. The binding of IgG molecules to erythrocytes is enhanced in isotonic solutions of low ionic strength [4, 12]. IgG fixation was found to be influenced by the presence of polyvalent ions [11]. Structural properties of IgG molecules may also have a role in the interaction. Fidalgo and Najjar et al. isolated molecules with “erythrophilic” property, i.e. a high affinity to red blood cells [13 — 15]. Our previous investigations proved the higher binding capacity of papain resistant IgG molecules to erythrocytes in comparison with the papain sensitive population [9—11]. The aim of the present investigations was a further characterization of the non-specific interaction between red blood cells and IgG molecules. Material and Methods IgG was prepared from sera of healthy donors by the DEAE-Sephadex batch technique [16]. Fab, Fc and F(ab’)2 fragments of IgG molecules were prepared from papain or pepsin-digested IgG preparations by chromatography. Purity of the preparations was controlled by immunoelectrophoresis. Erythrocytes prepared from fresh human blood were washed three times with physiological saline solution. Fixation of the IgG to red blood cells as well as the elution of the non-specifically bound IgG molecules was performed as Haematologia 6, 1972