IMMUNOLOGICAL PROPERTIES OF TG CARBOHYDRATES - ENHANCEMENT OF TG IMMUNOREACTION BY REMOVAL OF SIALIC-ACID

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  • 1 January 1976
    • journal article
    • research article
    • Vol. 25  (2) , 234-243
Abstract
Immunoreaction od desialylated and native thyroglobulin was compared in the sera of patients with anti-thyroglobulin antibodies by radioimunoassay with 125I-labeled thyroglobulin. Two human thyroglobulins were iodinated in vivo and by lactoperoxidase. After desialylation enhancement of immunoreaction was observed in several sera ranging from marginal to more than 100%. The effect was not due to iodination since it was reproducible with desialylated thyroglobulin labeled in vivo. In 1 serum, a marked enhancement was only seen with 1 thyroglobulin suggesting that desialylation may unmask isoantigens of thyroglobulin. Glycopeptides prepared from human thyroglobulin inhibited the immunoreaction between native thyroglobulin and autoantisera. The results indicate that sialic acid masks antigenic determinants in human thyroglobulin, and that carbohydrates might be the determinants involved in the process of autoimmunization.