Abstract
Diabetic retinopathy (DR) is the most significant and common cause of visual impairment in diabetes patients. The aim of the study was to enhance the understanding of the pathogenesis of DR associated with metabolic syndrome (MS) and elucidate the role of cellular and humoral immunity factors. The study included 130 patients. Group 1 comprised 70 patients diagnosed with DR and insulin-dependent type 2 diabetes against the background of MS. Group 2 included 60 patients diagnosed with DR and non-insulin-dependent type 2 diabetes associated with MS. The immunological analysis focused on evaluating subpopulations of blood lymphocytes using flow cytometry; systemic inflammation markers, such as CRP, specific IgA, IgM, and IgG, cytokines measured by ELISA. Significant changes in immune status were observed in patients with DR associated with MS, depending on diabetes compensation. In Group 1 patients with DR, more pronounced alterations in the T-cell immunity pathway were observed, including T-cell immunodeficiency accompanied by the activation of killer and B-cell immunity, compared to non-insulin-dependent patients. Both groups exhibited type IV hypersensitivity reactions. Elevated CRP level was detected only in insulin-dependent patients with DR. An analysis of the immune parameters indicated predominant activation of the specific humoral immunity pathway, suggesting chronicity of the condition. Non-insulin-dependent patients showed significant activation of mucosal humoral defenses and early humoral protective mechanisms. The data revealed more pronounced changes in specific humoral immunity markers, such as immunoglobulins, compared to systemic inflammation markers like CRP.