Evaluation of plasma cytokine protein array profile: the highlighted PDGF-BB in rheumatoid arthritis.

Objectives: The cytokines play critical roles in the complex pathogenesis of rheumatoid arthritis (RA), but the specific cytokines are still in need of being discovered. This multi-stage study was performed to identify novel RA cytokines in plasma and further understand the pathological mechanism of the identified cytokines.

Method: The plasma cytokine protein profile was evaluated by using Human Cytokine Antibody Array 440 in 18 subjects (RA: healthy control = 9:9). Then, enzyme-linked immunosorbent assay (ELISA) was used to validate the highlighted cytokines in 80 subjects (RA: healthy control = 40:40). Further functional experiments on fibroblast-like synoviocytes were performed to identify the pathological mechanisms of the highlighted cytokines for RA.

Results: A total of seven significant cytokines have differential expressions between RA patients and controls (fold change (FC) > 2, P value < 0.05). The difference in plasma for the highlighted platelet-derived growth factor (PDGF)-BB was validated in an independent validation sample (P = 0.005). Further, the PDGF-BB obviously promotes cell proliferation of MH7A cell, probably by inhibiting cell apoptosis and accelerating the cell cycle. The PDGF-BB can also promote MH7A cell migration.

Conclusions: This study evaluated the plasma cytokine protein array profile associated with RA and highlighted the importance of PDGF-BB. PDGF-BB has an important role in RA-FLS proliferation and migration. These results suggest that PDGF-BB might contribute to occurrence and development of RA. Key Points • The levels of plasma cytokines were systemically tested using Human Cytokine Antibody Arrays. • The expression difference of PDGF-BB was validated in an independent sample. • PDGF-BB obviously promotes cell proliferation and migration in RA-FLS.