Antibodies against hydroxyethylstarch produced in rabbits by immunization with a protein-hydroxyetylstarch conjugate.

Antibodies (ABS) against hydroxyethylstarch (HES) were raised in rabbits by immunization with HES-bovine serum albumin conjugate. ABS against HES were demonstrable by gel diffusion, passive hemagglutination (PH) and passive cutaneous anaphylaxis (PCA); specificity was confirmed by inhibition of PH and neutralization of PCA. No ABS against starch could be induced in comparative experiments. Non-immunogenicity of starch was attributed to its structural similarity with glycogen, widely distributed in animal species. Absence of cross-reactivity of anti-HES ABS with starch, amylopectin and glycogen and strong reactivity with 2-hydroxypropylstarch (DS = 0.65) and HES (DS = 0.7-1.2) indicate that hydroxyethyl substitution created antigenic determinants and conferred new immunochemical identity on the modified starch molecule. Anti-HES ABS represent specific analytical tools for the identification and quantitation of HES in biological material.