Primary Sjögren's syndrome (pSS) is an autoimmune disease affecting exocrine glands. Both autoreactive T cells and B cells are involved in the development of pSS, but their exact contribution to the pathogenesis is not clear. Here, we aimed to investigate the association of B-cell activating factor (BAFF) and interleukin (IL)-17A with subphenotypes of pSS.
Peripheral blood samples were collected from 31 pSS patients and 28 healthy controls. The serum levels of BAFF and IL-17A were quantified by sandwich ELISA.
The increased circulating BAFF levels are associated with higher immunoglobulin G (IgG) levels (P = 0.0167) and anti-Ro/SS antigen A autoantibody (P = 0.032), while the elevated circulating levels of IL-17A are associated with lower C3 levels (P = 0.0213) and higher focus score of salivary gland tissue (P = 0.002).
Our results show that BAFF and IL-17A are associated with different subphenotypes of pSS, suggesting both humoral and cellular immune response are involved in the pathogenesis of pSS.