Distinct patterns of cytokine secretion characterize new onset synovitis versus chronic rheumatoid arthritis.

OBJECTIVE

To compare patterns of cytokine secretion in patients with new onset synovitis (< 1 yr duration, n = 14), chronic rheumatoid arthritis (RA) (n = 16), and healthy controls (n = 17).

METHODS

ELIspot assays were used to detect mononuclear cells in the peripheral blood (PMBC) and synovial fluid (SFMC) secretion the type 1 cytokines interleukin 2 (IL-2) and interferon-gamma (IFN-gamma), the type 2 cytokines IL-4, IL-6 and IL-10, and the inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha). Results were correlated with measures of disease activity.

RESULTS

Patients with new onset synovitis had increased (p < 0.05) numbers of PBMC secreting IL-2. The number of PBMC secreting IFN-gamma correlated with the joint score in the new onset synovitis population (p = 0.006). By comparison, patients with chronic RA had significantly increased numbers of PBMC secreting IL-6, IL-10, and TNF-alpha (p < 0.05). The production of these cytokines correlated with joint score in chronic RA (p = 0.008, 0.06, 0.001, respectively).

CONCLUSION

Patients with new onset synovitis have increased numbers of PBMC secreting IL-2 and IFN-gamma, while patients with chronic RA have increased numbers of PBMC secreting IL-6, IL-10, and TNF-alpha. Correlations between joint score and number of PBMC secreting cytokines suggest the number of PBMC secreting IFN-gamma is most relevant in new onset synovitis, while the number of PBMC secreting IL-6, IL-10, and TNF-alpha is of greater relevance in chronic RA.