The role of infections in Behçet disease and neuro-Behçet syndrome

•Polyclonal immune activation in individuals with BD or NBS•Raised sera IL-8 levels in individuals with BD or NBS even under treatment•No specific virus effect•No differences in sera IgG or cytokines values for individuals with BD or NBS

Infections are considered an environmental trigger for exacerbations of immune-mediated diseases.We aimed to establish if common viral infections could be identified as a precipitant of Behçet disease (BD) with or without neurological involvement and to assess the variability of the immune response to common viruses. We also investigated whether cytokines and chemokines could be markers of neurological involvement. Finally, we explored if anti-basal ganglia antibodies (ABGAs) would be associated with neurological involvement in BD. Our study included 14 individuals with BD with neurological involvement (neuroBehçet syndrome — NBS), 16 individuals with BD without neurological involvement and 18 healthy controls (HC).Overall we found a tendency for increased levels of anti-viral IgG antibody levels in BD, more evident in NBS patients versus HC. Epstein–Barr viral-capsid antigen IgG titres were increased in NBS patients versus other BD patients (p = 0.032). Anti-measles antibody titres induced by vaccination were similarly elevated. ABGAs were not detected in the serum of our cohort. Raised levels of serum IL-8 in some BD patients did not reflect clinical activity or severity.In conclusion, there was evidence for a polyclonal immune activation rather than a specific virus effect in the sera of individuals with BD or NBS.