Background Several investigations of synovial fluid (SF) and membrane derived T cells show a predominant Th1 response with high IFN-gamma production from rheumatoid arthritis (RA), and a predominant Th2 response with high IL-4 and IL-10 production in T cells from spondyloarthropathy (SpA) joints.
Objectives To investigate the concentrations of IFN-gamma, TNF-alpha, IL-4, IL-10, the Th1 propagating cytokines IL-12 and IL-18, and the monokine IL-1 in sera and synovial fluids from RA and SpA patients.
Methods Patients were selected according to the ACR classification criteria for RA (n = 13), and the ESSG classification criteria for SpA (n = 14). Cytokine concentrations were measured using commercial ELISA kits. Results are expressed as mean ± standard deviation, significance was calculated using the Mann-Whitney U-test for untailed groups. Sera from 8 healthy donors served as controls.
Results IFN-gamma concentrations were significantly lower (4,3 ± 2,6 pg/ml), but IL-18 (78,8 ± 29,3 pg/ml), TNF-alpha (105,4 ± 40,9 pg/ml), and IL-10 (100,1 ± 69,7 pg/ml) concentrations were significantly higher in RA than in SpA-SF (IFN-gamma 12,9 ± 10,4 pg/ml, p = 0,009, IL-18 55,1 ± 44,1 pg/ml, p = 0,038, TNF-alpha 74,1 ± 85,0 pg/ml, p = 0,044, IL-10 14,1 ± 19,9, p < 0,0001). IL-4 and IL-12 concentrations were rather low in RA- and SpA-SF. Serum concentrations of all investigated cytokines in RA and SpA differed – if at all -only marginally from the situation in healthy donors.
Conclusion Synovial fluid concentrations of the Th1 and Th2 cytokines in RA and SpA do not generally reflect the state of Th1/Th2 balance at the single cell level. There is strong evidence for substantially higher amounts of IL-10 in RA than SpA synovium, reflecting strong antiiflammatory processes are present in RA synovium. The observed Th1/Th2 balances in both investigated diseases are not explained by the corresponding IL-12 and IL-18 SF concentrations.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.