Relationship between α1‐antitrypsin inactivation and tumor necrosis factor α concentration in the synovial fluid of patients with rheumatoid arthritis

Abstract

Objective. To examine the relationship between α₁‐antitrypsin (α₁AT) specific activity and tumor necrosis factor α (TNFα) concentration in synovial fluid from 48 patients with rheumatoid arthritis. Methods. The specific activity of α₁AT was calculated from the measurement of α₁AT concentration (by rocket immunoelectrophoresis) and elastase inhibitory capacity. TNFα was detected by enzyme‐linked immuno‐sorbent assay. Results. TNFα concentrations correlated with the extent of α₁AT inactivation. Conclusion. Our findings are consistent with a role of elastase in TNFα release within the inflamed joint.