Evaluation of subpopulations of T lymphocytes in psoriasis patients during therapy

The immune cells and cytokines are involved in the initiation and development of psoriatic inflammation. Nonetheless, the role of T-cell subpopulations in psoriasis is not fully understood. Our work presents the results of a study to determine the level, phenotype, and clinical significance of certain subpopulations of peripheral T cells of patients with psoriasis during therapies. We observed 68 patients with psoriasis (30 men and 36 women) who were divided into two groups depending of the treatment (selective phototherapy and selective phototherapy plus methotrexate). Healthy volunteers (10 men and 12 women) were included as the control group. Subpopulations of T cells (CD3⁺, CD4⁺, CD8⁺, Treg) were determined using flow cytometry. Interleukins levels (IL-1β, IL-2, IL-6, TNFα, IFNγ) were analyzed using an enzyme-linked immunosorbent assay. Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) were used for treatment efficacy assessment. A moderate correlation was observed between PASI and Treg (R = -0.38), CD3⁺ (R = -0.30), CD4⁺ (R = -0.32), and CD8⁺ (R = 0.42). A significant correlation was noted between DLQI and Treg (R = -0.38), CD3⁺ (R = -0.30), CD4⁺ (R = -0.35), and CD8⁺ (R = 0.35), thereby indicating a tendency to restore the balance of lymphocyte subpopulations during therapy. This tendency was most pronounced in the group treated using methotrexate and selective phototherapy.