Presence of neutrophil extracellular traps in superficial venous thrombosis of Behçet's disease.

Behçet's disease (BD) has a heterogeneous spectrum of disease manifestations featuring the involvement of different organs and can be characterized with different symptoms depending on the clinical department in charge. We retrospectively reviewed BD patients seen at our hospital and investigated the presence of neutrophils producing neutrophil extracellular traps (NET) in those patients. Immunolabeling of myeloperoxidase and histone citrullination proteins was performed on skin biopsies from three BD patients who had skin biopsy-proven superficial vein thrombophlebitis in their erythema nodosum-like lesions. We observed a higher proportion of female patients and a higher incidence of acne-like eruptions among BD patients seen at our dermatology department, while there was a higher incidence of ocular and gastrointestinal involvement among BD patients treated in other departments. We suggest that sex statistical trends could lead to the co-development of different manifestations and may help clinicians choose the best therapeutic approaches, tailoring them to the specific phenotype of the patient rather than one based on single disease manifestations. NET were found in neutrophils of panniculitis concurrent with superficial vein thrombophlebitis. We suggest that the pathogenesis of BD-related thrombosis could be associated with neutrophil activation and NET are released in the panniculitis of affected skin lesions, erythema nodosum-like lesions.