Cellular-versus-humoral autoimmune responses to salivary gland in Sjögren's syndrome.

In Sjögren's syndrome (SS), the earliest glandular infiltration by lymphoid cells surrounds the salivary ducts, which are also the target of the organ-specific antisalivary duct (ASD) autoantibody found in some patients with this disorder. A sensitizing antigen localized in ductal epithelial cells may elicit both humoral and cellular immune responses. In a study using coded specimens from twenty-five patients with SS and eight with rheumatoid arthritis, sera were tested for ASD, and lip biopsies were graded for the degree of lymphoid infiltration and destruction of labial salivary glands. Significantly less cellular infiltration was found in SS patients who had ASD compared to those who lacked this antibody. In SS, the group of ASD-negative patients had greater gland destruction and more severe xerostomia. The possible role of ASD as a blocking antibody is suggested.