Antibody to intermediate filaments of the cytoskleton in patients with Behçet's disease

Abstract

Antibodies to 10-nm intermediate filaments (anti-IF) were determined in the sera of 30 patients with Behçet's disease (BD), in addition to C-reactive protein and C9, and a attempt has been made to determine whether the presence of anti-IF indicate disease activity. The vimentin type of anti-IF was found to be positive in 14 out of 30 patients with BD (47%), whereas it was positive in 35% of the patients with rheumatoid arthritis (20 cases), 16% of the patients with systemic lupus erythematosus (19 cases) and in only 9% of the normal controls. The anti-IF were predominantly IgG class and the titers in BD were significantly higher than those in normal controls. Out of the 14 patients with anti-IF, 10 showed significantly increased levels of serum C9 and 8 showed increased levels of CRP activity. Only one patient showed increased C9, but was negative for anti-IF and CRP. The presence of anti-IF in the patients' sera was found to be a more sensitive indicator, though not specific, for the clinical assessment of disease activity.