Increased senescent CD8+ T cells in the peripheral blood mononuclear cells of Behçet's disease patients

Behçet's disease (BD) is a chronic inflammatory disease characterized by recurrent mucocutaneous, ocular, and skin lesions. Immunosenescence is associated with increased susceptibility to infection and chronic low grade inflammation. This study aimed to investigate the differences in the frequencies of immunosenescent cells in the peripheral blood mononuclear cells (PBMCs) of patients with BD. PBMCs were isolated from age-matched patients with active BD (n = 19), inactive BD (n = 20), disease controls (DCs, n = 15) and healthy controls (HCs, n = 15). The frequencies of senescent CD4+ T cells (CD3+ CD4+ CD27- CD28- cells), CD8+ T cells (CD3+ CD8+ CD27- CD28- cells) and B cells (CD19+ CD27- IgD- cells) were analyzed using flow cytometry. Senescence-associated β galactosidase activity was also measured in CD8+ T cells using flow cytometry with 5-dodecanoylaminofluorescein di-β-D-galactopyranoside. Frequencies of senescent CD4+ and CD19+ cells were not significantly different between the groups. The frequency of senescent CD8+ T cells was significantly higher in active BD than in DCs and HCs. C-reactive protein and erythrocyte sedimentation rate levels, which indicate disease activity, did not correlate with increased frequencies of immunosenescent cells. Steroid treatment, specific organ involvement, and HLA-B51 status did not have a significant influence on the frequencies of immunosenescent cells. Frequencies of senescence-associated β galactosidase+ CD8+ T cells were significantly higher in active BD and inactive BD compared to DCs and HCs. There was an increased frequency of senescent CD8+ T cells in the PBMCs of patients with BD.