Inflammatory status might direct ILC and NK cells to IL-17 expressing ILC3 and NK subsets in Behcet's disease.

Innate lymphoid cells (ILCs) are lymphoid cells that have important effector and regulatory functions in innate immunity and tissue remodeling. Uncontrolled activation and proliferation of ILCs can contribute to inflammatory autoimmune diseases. Behcet's disease (BD) is a complex systemic inflammatory disorder of unknown etiology. It has been shown that natural killer (NK) cells may play an immunoregulatory role in BD, however the role of ILCs is unknown. In this study, the levels and functions of ILCs and NK cell subsets in BD patients were investigated. Cell surface and cytotoxic granules (perforin and granzyme) expression of NK cells and ILCs were evaluated and labeled according to whole blood lysing protocol in peripheral blood samples obtained from the patients and healthy subjects. Cytokine levels of NK cells were investigated in stimulated peripheral blood mononuclear cells. All data were analyzed by flow cytometry. Total ILC and ILC3+ cells were increased in active BD patients compared to inactive BD patients and healthy subjects. There was no significant difference between the patients and healthy subjects regarding NK cell surface and intracellular molecule expression. Although, an increase in IFN-γ and IL-17, and a decrease in IL-4 levels were observed in CD56dim NK cell subset of BD patients. Recent studies showed increased neutrophilic infiltration and IL-17 secreting Th17 cells in BD patients. It is known that ILC3+cells are similar to Th17 subset regarding their cytokine profile and transcription factor expression patterns. Results of current study may suggest that inflammatory microenvironment in BD patients might direct ILC cells to differentiate into ILC3+ subset, and IL-17 released by NK cells might have a role in neutrophilic infiltration.

Vascular involvement in Behçet's disease: a retrospective analysis of 2319 cases.

BACKGROUND: Vascular lesions can be the presenting sign of Behçet's disease (BD) preceding classical symptoms. The aim of this study was to evaluate the prevalence and types of vascular involvement in BD. METHODS: Among 2319 patients diagnosed with BD according to the criteria of the International Study Group for BD, 332 patients (279 male, 53 female) with vascular involvement were included in this study. RESULTS: Prevalence of vascular involvement was 14.3%. Vascular involvement was found to be more common in males (P<0.001, male:female ratio 5.26:1). Mean age at onset of vascular involvement was 30.58+/-7.88. Vascular lesion was the presenting sign of BD in 50 patients (2.1%), whereas in 109 patients (4.7%) it started together with other clinical symptoms at the age of diagnosis. Superficial vein thrombophlebitis (SVT) was the most common vascular symptom (53.3%) followed by deep vein thrombosis (DVT) (29.8%). Arterial lesions were rare (3.6%). Of the patients 13.3% had more than one type of vascular involvement. Lower extremities were the most frequent localization in patients with SVT, whereas the femoral vein was mainly involved in patients with DVT and the pulmonary artery was mainly involved in the patients with arterial lesions. CONCLUSION: In countries like Turkey where BD is more frequent, young male patients presenting with vascular involvement should be evaluated for BD.