Abstract
Introduction: The aim of this study was to investigate cytokine profiles in patients with both rheumatoid arthritis (RA) and bronchial asthma (BA). METHODS: We studied 25 patients with RA, 25 with BA, and 25 with both RA and BA (BARA). A respiratory questionnaire was completed by all the patients, they underwent spirometry, and their production patterns of selected T helper (Th)1, Th2, and Th17 cytokines were assessed. RESULTS: BA patients had spirometry findings similar to BARA patients, while RA patients had normal spirometry. BA patients produced significantly higher levels of interleukin (IL)-5 (p = 0.03) and IL-10 (p = 0.03) than patients with RA. Median levels of IL-17A and IL-17F and interferon (IFN)-γ were higher (p = 0.001, 0.004, and 0.04) in RA patients than in BA patients. No differences were seen in the levels of cytokines produced by BA patients compared to BARA patients. IL-4 and IL-10 levels were higher (p = 0.04 and 0.03) in BARA patients than in RA patients, while levels of IL-17A and IFN-γ were higher (p = 0.037 and 0.009, respectively) in RA patients than in BARA patients. Ratios of Th1/Th2 and Th17/Th2 cytokines in most combinations were different between RA and BA, and between RA and BARA, but were similar in BA and BARA. CONCLUSIONS: Patients with both BA and RA have a Th2-dominant cytokine profile unlike patients with RA alone. These observations contribute to a better understanding of the immunopathogenesis of these diseases and to the management of patients using cytokine-based therapies.
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