Dichotomy of Local Th1- and Systemic Th2/Th3-Dependent Types of Immune Response in Rheumatoid Arthritis

Abstract

Biomarkers of activity of rheumatoid arthritis were analyzed in the blood serum and synovial fluid of affected joints in 84 patients. Significant differences between the serum and synovial fluid levels were revealed for 10 of 17 analyzed biomarkers; the levels of IgM and proinflammatory cytokines TNFα, IL-1β, IFNγ, and IL-6 were higher in the synovial fluid. The concentration of IL-10 in the synovial fluid was also elevated. In the peripheral blood, the content of antinuclear antibodies, circulating immune complexes, and cytokines IL-4 and TGF-β was elevated. These findings attest to the development of local Th1 type immune response in affected joints paralleled by compensatory elevation of immunosuppressive cytokine IL-10 and systemic Th2/Th3 type immune response (judging from peripheral blood parameters) in patients with rheumatoid arthritis.