Tumour necrosis factor alpha and interleukin-2 in plasma from rheumatoid arthritis patients in relation to disease activity.

Tumour necrosis factor alpha (TNF alpha) and interleukin-2 (IL-2) are potential immunological mediators of pathogenetic changes in rheumatoid arthritis. We measured the concentrations of TNF alpha and IL-2 in plasma from 2 groups of patients suffering from rheumatoid arthritis (RA). One group had high and one had low disease activity. In addition, in connection with steroid treatment in the high disease activity group, TNF alpha was significantly increased in plasma from RA patients with high disease activity compared with those of low disease activity (p = 0.0009). Furthermore, TNF alpha decreased significantly in relation to steroid medication, parallel to clinical improvement (p = 0.016). All IL-2 concentration measurements were within the estimated normal range. The increased TNF alpha plasma levels in patients with rheumatoid arthritis with high disease activity, might result from activated white mononuclear cells in the inflamed joints. This might, in part, support the theory that TNF alpha is a possible mediator of pathogenetic changes known to occur in rheumatoid arthritis.