Abstract
Fibronectin (FN) levels in plasma of patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), scleroderma, dermato-/polymyositis (DM/PM) and mixed connective tissue disease (MCTD), and FN levels in synovial fluid of patients with RA and osteoarthritis (OA) were measured by radioimmuno-inhibition assay. The mean FN level in plasma of SLE patients was higher than that of normal controls (603±104μg/ml vs 339±28μg/ml, p<0.01). In active SLE group, the mean FN level was higher than that of inactive group (764±135μg/ml vs 377±82μg/ml, p<0.01). The mean FN level in plasma of RA patients (469±43μg/ml) was higher than that of normal controls (p<0.01). In RA, plasma FN level did not correlate with the clinical activity. The mean FN level in synovial fluid of RA patients (1, 148±224μg/ml) was higher than that of osteoarthritis patients (548±60μg/ml, p<0.01) and that of plasma of RA patients (p<0.01). In RA, a significant correlation between the FN level in plasma and that in synovial fluid was observed. The mean FN level in plasma from patients with PSS (483±92μg/ml) and MCTD (1, 240±480μg/ml) were higher than that of normal controls, but the FN of DM patients was in the normal range (293±72μg/ml). These results suggest the quantitation of FN in plasma and synovial fluid is useful for the evaluation of the pathophysiology of collagen diseases.
