Serum proteins in human squamous epithelium

Abstract

A new immunoperoxidase staining technique of high specificity (the labeled antigen method) was used for the detection of serum proteins in the epithelium of human skin and mucous membranes. The majority of specimens contain cells showing strong diffuse intracellular staining. These cells usually lie in the upper mid-zone of the epithelium and are often charaterized by vacuolated or pyknotic nuclei. Double immunoenzymatic labeling (using alkaline phosphatase and peroxidase) showed that the different proteins are usually present in the same cells. A less frequent pattern of staining took the form of delicate strands of intercellular Ig[immunoglobin]G. Samples from a wide range of skin diseases were studied, but no clear relationship between positive epithelial staining and disease states was apparent. Serum proteins may enter epithelial cells by passive diffusion and attention is drawn to other instances (e.g., in the CNS and lymphoid tissue) where similar phenomena were observed by immunoenzymatic staining techniques.