DETECTION OF INCREASED LEVELS OF CIRCULATING INTERCELLULAR-ADHESION MOLECULE-1 IN SOME PATIENTS WITH RHEUMATOID-ARTHRITIS BUT NOT IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS - LACK OF CORRELATION WITH LEVELS OF CIRCULATING VASCULAR CELL-ADHESION MOLECULE-1

Objective. To compare the levels of circulating intercellular adhesion molecule 1 (cICAM-1) and vascular cell adhesion molecule I (cVCAM-1) in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Methods. Levels of cICAM-1 and cVCAM-1 were measured in both plasma and synovial fluid using monoclonal antibody sandwich enzyme-linked immunoassays. Results. Levels of both cICAM-1 and cVCAM-1 were significantly increased (P < 0.001) in RA patients compared with normal controls. In contrast, only cVCAM-1, and not cICAM-1, was increased in patients with SLE. Levels of cICAM-1 and cVCAM-1 were significantly elevated in synovial fluid compared with plasma in paired samples from patients with RA. There was no correlation between levels of cICAM-1 and levels of cVCAM-1, in either plasma or synovial fluid. Whereas levels of cVCAM-1 correlated significantly with the erythrocyte sedimentation rate (ESR) and C-reactive protein level in RA patients and with the ESR in SLE patients, no significant correlations were found between cICAM-1 and either of these indices of disease activity. Conclusion. These observations indicate that levels of cICAM-1 and cVCAM-1 reflect separate pathophysiologic processes. Both may be useful markers for the diagnosis and management of patients with rheumatic diseases.