Anti-alpha-enolase antibodies in Behçet's disease: a marker of mucocutaneous and articular disease activity?

Objective. To assess IgM anti-alphaenolase antibodies (AAEA) in systemic Behget's disease (BD) and its possible association with clinical manifestations and disease activity. Methods. Ninety-seven consecutively selected BD patients were compared to 36 enteropathic spondyloarthritis (ESpA) [24 Crohn's disease (CD) and 12 ulcerative colitis (UC)] patients and 87 healthy controls. 1gM AAEA was detected by immunoblotting. Disease activity was assessed by standardised indexes, Brazilian BD Current Activity Form (BR-BDCAF) for BD and HarveyBradshaw Index (HBI) for CD and UC patients. A second evaluation was performed in BD patients (n=56), regarding IgM AAEA presence, disease activity scores and C-reactive protein (CRP). Results. Higher IgM AAEA prevalence was found in 97 BD (17.7%) compared to ESpA (2.8%) and healthy controls (2.3%), p< O. O01. IgM AAEA frequency was higher in active BD compared to inactive BD (30.2% vs. 7.4%, p=O. O06), a finding confirmed in the second cross-sectional evaluation of 56 of these BD patients (45.5% vs. 13.3%, p=O. 02). Mean BR-BDCAF scores were higher in IgM AAEA positive group on both evaluations (9.1 + 5.4 vs. 4.9 + 4.9, p=O. O02; 5.0 + 4.9 vs. 2.2 + 2.9, p=O. 01, respectively). BD patients with mucocutaneous and articular symptoms presented higher IgM AAEA positivity in the first and second evaluations (64.7% vs. 27.5%, p=O. O05; 36.4% vs. 7.1%, p=0.039 respectively). Conclusions. Our data support the notion that alpha-enolase is a target antigen in BD, particularly associated with disease activity, mucocutaneous and articular involvement. In addition, IgM AAEA may distinguish BD from ESpA, especially in patients with high disease activity.