ABSTRACT
OBJECTIVE: To evaluate cytokine production and cellular proliferation index (CPI) in peripheral blood mononuclear cells (PBMC) of patients with ankylosing spondylitis (AS), and their association with clinical variables. METHODS: In a cross sectional study we compared the production of tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), and IL-10 and CPI in response to phytohemagglutinin (PHA) in PBMC of 27 patients with AS and 24 healthy controls. We also assessed clinical characteristics including disease activity index (BASDAI) and functional index (BASFI). RESULTS: Levels of IL-1beta were higher in patients with AS (median 242 pg/ml) than in controls (median 65 pg/ml); p = 0.002. No differences were observed in median levels of TNF-alpha or IL-10 between AS and controls. Patients had a reduction in CPI (1.2 in AS vs 1.8 in controls; p < 0.001). A positive correlation was observed between IL-10 production and age (rho = 0.34, p = 0.01). A borderline negative correlation was observed between CPI and age (rho = -0.26, p = 0.07). CONCLUSION: Patients with AS had high production of IL-1beta compared with controls and a poor response in CPI. These findings may explain the lack of response for microbial antigens mediated by the innate immune response.
