Serum Interleukin-33 in Behcet's Disease: Its Relation to Disease Activity and Clinical Manifestations

Behcet's disease (BD) is a chronic systemic inflammatory disorder characterized by a ‎‎course of remissions and exacerbations of unpredictable frequency and duration‎. Pro-‎inflammatory cytokines seem to be responsible for the enhanced inflammatory ‎‎response in BD.

This study aimed to investigate serum levels of IL-33 in patients with Behcet's disease (BD) and their relationship to disease activity and clinical manifestations. Thirty patients with BD were enrolled and subjected to assessment of disease activity according to Behcet's Disease Current Activity Form (BDCAF) score. Serum IL-33 levels were determined using Enzyme-Linked-Immunosorbent Assay (ELISA). Thirty age and sex matched rheumatoid arthritis patients and thirty healthy volunteers were included in this study as control groups. Serum IL-33 level was 132.5±19 pg\ml, 101.2±20.1 pg\ml and 31.5±10.5 pg\ml in RA, BD and healthy control groups respectively. IL-33 was significantly higher in BD patients (101.2±20.1pg/ml) as compared to healthy controls (31.5±10.5 pg/ml) but lower than rheumatoid arthritis patients (132.5±19.1 pg/ml). Levels of IL-33 were significantly increased in BD patients with skin lesions (Erythema nodosum & Acneiform lesions) and ocular lesions (retinal vasculitis) (P<0.05), and a positive correlation was found between BDCAF score and IL-33serum levels (r=0.9, P<0.001). In conclusions, serum IL-33 level is elevated in active BD patients with skin and ocular affection and correlates with disease activity.