Levels of BTLA,carriers in terms of CD127 and FOXP3 Treg Cells, BTLA (CD272), osteoprotegerin and sCTLA in Behcet's disease investigation

Behçet?s disease (BD) is a chronic, inflammatory vasculitis characterized by recurrent attacks of oral and genital ulcerations, ocular and skin lesions, arthritic and neurologic involvement. The intermittent nature of the disease and lack of consistent response to the therapy make the etiopathogenesis difficult to define.One important component of peripheral tolerance is represented by lymphocytes with regulatory functions, including CD4+CD25+Foxp3+ regulatory T cells (Tregs). CTLA-4 was determined a molecule CTLA-4 that inhibited lymphocyte activation. sCTLA is form of CTLA-4 that secreted into the extracellular space and described as a functional marker of Treg cells. B and T lymphocyte attenuator (BTLA, CD272) is a lymphoid specific cell surface receptor that is expressed by B cells, T cells, dendritic cells (DC), macrophages, and NK cells and participate in inhibitory signaling. Osteoprotegerin (OPG) and its ligand (RANKL) have a key role in controlling the orderly development and function of the immune system.In this study it was aimed to research whether CD4+CD25+Foxp3+ regulatory T cells (Tregs), sCTLA, BTLA and osteoprotegerin have a role on Behçet?s disease. The study is partly as an autoimmune disease; Behcet's disease was aimed at defining the role of inhibitory receptors. CD4+CD25+ Foxp3+ regulatory T cells, sCTLA, BTLA, OPG levels in twenthy-five patients with Behcet?s and twelwe healthy controls, matched for age and sex, were included in this study. Twenthy-five BD patients with ocular complications (9 with active ocular attack and 2 with inflammatory arthritis) and 5 patients with mucocutaneous lesions (2 in active period) were studied. A total of 25 patients (14 females, 11 males) Behçet?s disease whose ages mean (active BD : %38.23 ± 5.44 ,remmission BD : 36.92 ± 4.22) and their diagnosis years mean (active BD: 4.39 ± 1.29, remmission BD : 8.13 ± 2.04) were evaluated. All patients fulfilled the criteria defined by the International Study Group for diagnosis of Behçet?s disease. Disease activity was evaluated according to the published criteria. Twenty healthy volunteers matched for age and sex (9 men and 11 women; mean 29.56 ± 2.97 years) were included as control subjects, none of them had evidence of acute infection or chronic disease (e.g., other autoimmune or atopic disorders).Venous blood samples (2 ml) were collected aseptically into tubes with anti-coagulant (EDTA). We first analyzed the proportions of CD4+CD25+ cells in the peripheral blood of 25 patients with BD by using flow cytometry. Serum levels of OPG and sCTLA were determined by ELISA .As a result the proportions of CD4+CD25+ T cells in BD (median: 5.34 ± 0.65) were significantly higher than those in healthy controls (median:2.70 ± 0.20) . Concurrently BD patients (active and remision) had significantly higher CD4+CD25+FoxP3+ cells, as compared to healthy controls( BD median :3.96±0.59 , healthy controls median:1.38±0.25). However there was no differences in the Treg cells between active and remission BD. BD patients had significantly higher CD4+CD272+ T cells, as compared with healthy controls (p<0.001).But there was no difference between active and remission patient (p>0.05). OPG'in serum levels in patients with BD compared to healthy control group was found to be significantly higher (813.76 ± 10.14 vs 604.22 ± 33.57 pg/mL, P< 0.01). There was no difference between sCTLA-4 serum levels in Behcet?s patients (0.236 ± 0.12 ng/ml) and healthy controls (0.228 ± 0.07 ng/ml) (p>0.05). But Behcet's patients with active Behcet's disease and in remission sCTLA-4 found a significant difference between serum levels ( aktif BH: 0.064±0.14 remisyon BH:0.332 ± 0.91 ).Thus studied parameters may be concluded responsible for immune dysregulations in Behçet's disease.Key Word: Behçet?s disease, Treg cells, Foxp3, sCTLA, BTLA, Osteopotegerin