Variability of peripheral blood lymphocyte subsets in ocular Behcet’s disease

Neroev V.V., Sorozhkina E.S., Balatskaya N.V., Davidova G.A., Lisitsyna T.A.

Moscow Helmholtz Research Institute of Eye Diseases
V.A. Nasonova Research Institute of Rheumatology

Behcet's disease (BD) is a systemic vasculitis of unknown etiology, characterized by a combination of auto-inflammatory and autoimmune processes and the involvement of immunocompetent cells of innate and acquired immunity, respectively. Eye damage in BD (BU) is relapsing and manifests mainly by panuveitis with occlusive retinal vasculitis. The aim of the study was to characterize the immune status of patients with BD, depending on the nature of the pathological process that affects the eye.

The study included 77 patients with BU: 26 active uveitis patients (UA), 51 with uveitis in remission (UR); 8 patients with BD without ocular manifestations (systemic manifestations only) comprised comparison group (CG); 50 healthy volunteers without ocular pathology made up the control group. Relative and absolute counts of T-, B-, and natural killer (NK) cell populations, including CD4 and CD8, were determined in peripheral blood samples by flow cytometry.

Highest CD45+ and CD3+ values were observed in UA patients (2.24±0.018×109/l; and 1.724±0.015×109/l respectively, p <0.05).

Increased relative amount of CD3+CD8+ was detected in 55% of patients with UR, in 50% with UA and in CG. An increase in the absolute number of these cells became a characteristic feature of the UA group, where this shift was detected in 57% of cases.

Minor subpopulation CD3+CD4+CD8+ tended to increase, reaching a maximum in CG (1.6±0.6% and 0.030±0.011 x109/l). A statistically significant decrease in NK (CD16+CD56+) was detected in the blood of all patients. The most pronounced deprivation was observed in CG (8.7±1% and 0.16±0.022 x109/l).

These results are important for understanding the pathogenesis of BD and its complications; the dynamics of changes in the amount of lymphocyte subsets in patients with BD can be of value in determining the risk groups for relapse and assessing the severity of the underlying ocular disease.