To investigate the expression of CD4+CD25+ regulatory T cell (Treg) in labial gland (SG) of the patients with Sjögren's syndrome (SS).
Specimens of labial gland were obtained from 25 primary SS patients and 6 healthy controls during biopsy to be made into serial sections. Immunohistochemistry was used to examine the expression of CD25, CD4, CD8, CD68 and Foxp3.
Infiltration of a great amount of mononuclear cells and atrophy of part of the labial glands were seen in the specimens from SS patients. The percentage of CD4+ T cells in the infiltrating leucocytes of the SS patients was (44.2 +/- 20.5)%, significantly higher than that of the controls [(9.2 +/- 6.0)%, P < 0.01]. CD25 and Foxp3 were completely absent in the specimens from both the controls and SS patients.
CD4+CD25+ regulatory T cell lacks in the labial gland of SS patients. CD4+CD25+ regulatory T cells play a key role in the progression of SS.