The Presence of Autoantibodies Against Vascular and Nervous Tissue in Sera From Patients with Neuro-Behçet's Disease.

Introduction: Behçet's disease is a chronic inflammatory disease of unknown aetiology that affects multiple organ systems. Since the diagnosis of this disease mainly relies on clinical criteria, a diagnostic laboratory test is required especially for neuro-Behçet's patients without systemic involvement.

Method: In this study, we searched for the presence of autoantibodies against brain tissue, by means of indirect immunofluorescent staining technique in sera obtained from patients with neuro-Behçet's disease, based on reports that humoral immune dysregulation may play a role in susceptibility to Behçet's disease. After pre-absorbtion of sera with guinea pig liver powder to reduce nonspecific staining, serum samples were applied to mouse brain sections and immunoreactivity was detected with fluorescein (FITC)-conjugated goat antibody against human IgG.

Results: Ten sera from neuro-Behçet's patients and 10 age-matched control sera were screened for immunoreactivity. We detected specific immunoreactivity to both parenchymal and vascular brain structures in the patients' sera. Parenchymal vessel immunopositivity was detected in 8 of 10 patients, whereas only two of control sera showed no significant parenchymal vascular immunoreactivity (p=.025). In addition to vascular immunoreactivity, filamentous and reticular immunopositive structures were detected in brain sections of 5 out of 10 patients. No such immunoreactivity was detected in sections incubated with control sera (p=.016).

Conclusion: We detected a specific immunoreactivity against vascular and parenchymal filamentous structures in neuro-Behçet patients' sera. Humoral autoimmunity may play a role in the pathogenesis of neuro-Behçet's disease in addition to cellular immune response. Findings of this preliminary study will be evaluated with a large number of patients and controls, to determine whether it is the cause or the result and, further studies are underway to disclose the nature of epitope to which the immunoreactivity was directed against and to develop a diagnostic laboratory method for investigating central nervous system involvement in Behçet's patients.