Time Required for Cortisone Acetate Therapy to Increase the Survival of IgG - Sensitized Erythrocytes
نویسنده
چکیده
tute two important therapeutic modalities in the treatment of autoimmune hemolytic anemia. Each of these may affect both the rate of synthesis of autoantibody and the clearance of antibody sensitized cells. The latter possibility has been examined in an experimental model which allows evaluation of the role of antibody and complement in the immune clearance of erythrocytes in molecular terms. The in vivo clearance of 51Cr-labeled guinea pig erythrocytes sensitized with purified rabbit IgG or IgM antibody to produce a known number of complement-fixing sites per cell was studied. Corticosteroid therapy increased the survival of both IgG and IgM sensitized erythrocytes by decreasing sequestration in the reticuloendothelial system (RES). 5 days of therapy prior to injection of antibody coated cells were required for a maximal effect. It appeared that the RES of cortisone-treated animals had a lowered sensitivity to erythrocytes coated with antibody and complement and the cells were removed as though they were coated with fewer complement sites/cell. The general pattern and kinetics of clearance and the localization of sequestered cells were not modified by corticosteroids. As the number of IgG Cl-fixing sites was increased, the difference betwen cortisone treated and control animals was less marked. Splenectomy led to an increased survival of IgG-coated cells and a sixfold increase in IgG Cl-fixing sites was necessary in order to obtain similar rates of clearance in splenectomized and control animals. The liver was responsible for this much less efficient clearance of cells in splenectomized animals; the clearance pattern was typical of that noted for IgG. No effect at all was noted on the clearance of IgAM sensitized cells in splenectomized
منابع مشابه
Role of antibody and complement in the immune clearance and destruction of erythrocytes. II. Molecular nature of IgG and IgM complement-fixing sites and effects of their interaction with serum.
A model for the immune clearance and destruction of homologous erythrocytes has been further explored. In this model, every IgM anti-erythrocyte antibody molecule in an antibody preparation was shown to fix Cl. About 2000 IgG antibody molecules were required to form a Cl-fixing site on the guinea pig erythrocyte surface. 60 IgM complement-fixing sites per erythrocyte were required for the immun...
متن کاملRole of antibody and complement in the immune clearance and destruction of erythrocytes. I. In vivo effects of IgG and IgM complement-fixing sites.
A model which permits evaluation in molecular terms of the role of antibody and of complement in the immune destruction of erythrocytes was established in the guinea pig. IgM and IgG immunoglobulins were isolated from rabbit anti-guinea pig erythrocyte antisera and were used to sensitize (51)Cr-labeled guinea pig erythrocytes. The average number of complement-fixing sites per erythrocyte formed...
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