چکیده (انگلیسی):

Background: Interleukin (IL)-17A plays a pivotal role in the pathogenesis of rheumatoid arthritis (RA).
The expression of IL-17A in synovial mast cells (MCs) in RA and osteoarthritis (OA) has been reported, but
the frequencies of IL-17A expression in synovial MCs have varied. The aim of this study was to investigate
whether IL-17A expression is upregulated in human synovial MCs in RA and to elucidate the mechanism
of IL-17A expression in synovial MCs.
Methods: Synovial tissues were obtained from patients with RA or OA undergoing joint replacement
surgery, and synovial MCs were enzymatically dispersed. Synovium-derived cultured MCs were generated
by culturing synovial cells with stem cell factor. IL-17A expression was investigated using immunofluorescence
in synovial tissues. IL-17A mRNA expression and its production from MCs were examined
using RT-PCR and ELISA, respectively.
Results: The number of IL-17A-positive (þ) synovial MCs and the percentage of IL-17Aþ MCs among all the
IL-17Aþ cells from RA patients were not significantly increased compared with those from OA subjects.
The synovium-derived cultured MCs spontaneously released small amounts of IL-17A. Neither IgE- nor
IgG-dependent stimulation increased IL-17A production from the MCs. IL-33, tumor necrosis factor-a,
C5a, lipopolysaccharide or IL-23 plus IL-1b did not affect IL-17A production in MCs.
Conclusions: The synovial MCs are not a main source of IL-17A in RA.