Effect of pore size of porous bead carriers immobilizing antibody on IgE absorption.

Immunoglobulin E (IgE) adsorption was studied using antihuman IgE antibody immobilized on alkylamine glass carriers with different pore sizes (Controlled Pore Glass [CPG]) to determine the effect of pore size on IgE absorption in therapeutic immuno-adsorbents. With a series of CPGs whose pore sizes were in the range of 170 to 1400 A, CPGs possessing pore sizes larger than 500 A had higher IgE absorption. A CPG (500-A pore size) with the spacer arm 20 A long did not give better IgE removal than CPG without the spacer arm, since the spacer prevented the immobilization of a sufficient amount of the antibody on the carrier because of steric hindrance. However, the antibodies, once immobilized on CPG with the spacer arm, bound the same amount of IgE molecules (antigens) as those immobilized on CPG without the spacer arm.