Characteristics of Immunomorphological Processes in the Spleen of Patients with Immune Thrombocytopenia
The aim of the study was to characterize the immunomorphological processes in the spleen of patients with immune thrombocytopenia depending on the form of the disease and the response to splenectomy. Material and methods. The study included the spleens of 50 patients with immune thrombocytopenia, including 32 women (64%) and 18 men (35%). The median age was 38.0 (22.8; 52.0) years. Depending on the form of the disease, all patients with immune thrombocytopenia were divided into three groups: first diagnosed disease (n=12); persistent form (n=20); and chronic form (n=18). All cases of immune thrombocytopenia were divided into two subgroups: 1 (n=32) - patients who were in remission after splenectomy; 2 (n=18) - people with refractory disease after splenectomy The comparison group was represented by spleens autopsy material of 20 people who had no history of blood system and liver diseases, or other pathology. The median age was 39 (27; 65) years. Histological, immunohistochemical, and morphometric methods were used to study the size of the red and white spleen pulps, as well as their cellular composition. Results. In patients with immune thrombocytopenia who responded to splenectomy, the spleen morphology was characterized as corresponding to stages I-II of the immune response. In the subgroup with a refractory course of the disease and in patients with a persistent form, the condition of the spleen corresponded to stages II-III of the immune response, which indicated a longer or aggressive course of the disease. Reducing the size of the periarterial lymphoid muffs, regardless of the response to splenectomy in relation to the comparison group (p<0.05), reflects the pathogenesis of the disease and presents the effect of immunosuppressive therapy on T-cell area of white pulp. Changes in the cell composition of the spleen in patients with immune thrombocytopenia were characterized by an increase in the relative and absolute number of B and T lymphocytes in the white and red pulps, macrophages (CD68<sup>+</sup>) and dendritic cells (CD35<sup>+</sup>, S100<sup>+</sup>). An increase in the content of lymphoid elements expressing CD4<sup>+</sup> in white and red pulps, as well as CD8<sup>+</sup> T-lymphocytes in the red pulp indicates a multifactorial development of autoimmune disorders in this disease. A significant increase in the number of cytotoxic CD8<sup>+</sup> T cells and CD68<sup>+</sup> macrophages in the red pulp in patients with refractory course of immune thrombocytopenia compared to those who responded to splenectomy (p<0.05) indicates that cytotoxic T-lymphocytes along with macrophages are actively involved in the destruction of platelets in patients resistant to the surgical treatment of the disease. Morphometric criteria for unfavorable prognosis of immune thrombocytopenia after splenectomy were determined.