The purpose of this study was to examine whether antibodies against CD4 are present in patients with primary Sjögren's syndrome, and to explore the possible correlation between these antibodies and the CD4+ T lymphocyte depletion that is seen in some Sjögren patients.
Sera from 214 patients with primary Sjögren's syndrome, 154 healthy blood donors, 38 age- and sex-matched controls without autoimmune disease, and 77 HIV-1-seropositive individuals were analysed by an enzyme-linked immunosorbent assay (ELISA) using recombinant soluble CD4 as the antigen.
Anti-CD4 antibodies were observed more frequently in patients with Sjögren's syndrome (12.6%) as compared with the control groups (0.6%) (P < 0.001), and at a level similar to that seen among the HIV-1 patients (13.0%). However, no correlation was found between the presence of anti-CD4 antibodies and CD4+ T lymphocytopenia in the Sjögren patients.
This is the first study that shows anti-CD4 antibodies in patients with primary Sjögren's syndrome. The significance of these antibodies in the immunopathogenesis of Sjögren's syndrome remains to be determined.