Epithelial Transport Receptor

Secretory Component Glycoprotein is an epithelial transport receptor for polymeric IgA and IgM. Antibody to secretory component has been shown to be useful for identifying glandular carcinomas. Defects in Secretory Component Glycoprotein are the cause of lipoid proteinosis (LiP), also known as lipoid proteinosis of Urbach and Wiethe or hyalinosis cutis et mucosae. LiP is a rare autosomal recessive disorder characterized by generalized thickening of skin, mucosae and certain viscera. Classical features include beaded eyelid papules and laryngeal infiltration leading to hoarseness. Histologically, there is widespread deposition of hyaline material and disruption/reduplication of basement membrane.