Human anti-alpha-enolase antibody in sera from patients with Behçet's disease and rheumatologic disorders.

Objective. α-Enolase is a target antigen of IgM-type anti-endothelial cell antibody in patients with Behcet's disease (BD). The objective of this study was to assess the reactivity of serum anti-α-enolase antibodies in BD and in other rheumatologic diseases, and to evaluate the clinical significance of serum anti-α-enolase antibodies in BD. Methods. Enzyme-linked immunosorbent assay (ELISA) and immunoblotting were used to examine serum samples from patients with BD (n= 100), systemic lupus erythematosus (SLE) (n=50), systemic sclerosis (n=21), rheumatoid arthritis (RA) (n=20), Takayasu's arteritis (n=20), dermatomyositis (n=17), mixed connective tissue disease (MCTD) (n=11), and samples from healthy volunteer donors (n=23). The medical records of patients with BD were reviewed to investigate their clinical characteristics. Results. Specific positive signals against recombinant human α-enolase were detected by IgM ELISA of serum samples from 56 of the 100 BD patients (56.0%), 24 of the 50 SLE patients (48.0%), 15 of the 21 systemic sclerosis patients (71.4%), 13 of the 20 RA patients (65.0%), 10 of the 20 Takayasu's arteritis patients (50.0%), 9 of the 17 dermatomyositis patients (52.9%), and 5 of the 11 MCTD patients (45.5%). The number of BD patients with vascular lesions was significantly higher in the anti-α-enolase antibody positive group than in the negative group (p=0.027). Conclusions. We demonstrated the reactivities of serum anti-α-enolase antibodies in BD and other rheumatologic diseases with moderate specificity and also found that serum anti-α-enolase antibodies in BD can be associated with vascular system involvement.