To determine the involvement of CD40 in chronic activation of rheumatoid arthritis (RA) synovial monocytes.
CD40 expression on RA synovial monocytes was examined by immunostaining. Involvement of CD40 in tumor necrosis factor-alpha (TNF-alpha) secretion from RA synovial fluid mononuclear cells (SFMC) was examined by blocking with anti-CD40 antibody.
CD40 was expressed on RA synovial monocytes. TNF-alpha secretion from RA SFMC was enhanced by CD40 ligand stimulation. Spontaneous secretion of TNF-alpha from RA SFMC was inhibited by anti-CD40 antibody.
CD40 was involved in the activation of RA synovial monocytes that leads to TNF-alpha production.