IgA, IgG and IgM immunohistochemical staining in normal dog salivary glands and in cases of chronic sialadenitis.

As part of a study of normal and diseased dog salivary glands, a peroxidase-antiperoxidase immunohistochemical method was applied to study IgA, IgG and IgM staining in the major and minor salivary glands in normal dogs and in cases of sialadenitis. In normal glands, IgA was present in the plasma cells of the interlobular connective tissue and in secretory acinar epithelial cells; duct epithelium was also stained. IgG- and IgM-staining was confined to interstitial plasma cells; no epithelial staining was seen. In all glands, IgA-containing plasma cells were more numerous than those containing IgG or IgM. Larger numbers of cells containing each immunoglobulin were present in sublingual glands than in parotid, submandibular, zygomatic, palatine or tongue glands. In the submandibular glands in which there were signs of salivary gland inflammation, there were increased numbers of plasma cells containing each of the immunoglobulin isotypes but the proportion of different isotypes was unchanged.