Tumour necrosis factor soluble receptors behave as acute phase reactants following surgery in patients with rheumatoid arthritis, chronic osteomyelitis and osteoarthritis

Abstract

Tumour necrosis factor-alpha (TNF-α) is involved in diverse biological processes including immune and inflammatory reactions and the response to surgical stress. Two soluble TNF receptor protein fragments, TNF-sR55 (from the p55 kD TNF receptor) and TNF-sR75 (from the p75 kD TNF receptor), are released by cells during inflammation and may modulate the effects of TNF-α. We have studied the kinetics of secretion of TNF-α, TNF-sR55 and TNF-sR75 in the sera of patients with rheumatoid arthritis (RA) and control subjects with osteoarthritis (OA) or chronic osteomyelitis (OM) before and after major surgery. Significantly higher pre-operative levels of TNF-sR55 and TNF-sR75 were found in RA and OM as compared with OA (P < 0.02). Following surgery, TNF-sR55 increased within 24 h in RA, OM and OA (P < 0.05), whereas TNF-sR75 increased significantly only in OM and OA patients (P < 0.05). By contrast, no TNF-α was detectable before and after surgery in any of the subjects, but this may have been due to impaired detection (by ELISA) of TNF-α when it is bound to TNF-sR. These findings suggest that TNF-sR55 and TNF-sR75 may be further markers of the host's reaction to inflammatory insults. They may also play a role in modulating the immune and inflammatory reactions by inhibiting the systemic effects of TNF-α.