The number and subgroups of lymphocytes in valve tissue of rheumatic heart disease combined with diabetes mellitus

: Objective To investigate the effect of diabetes mellitus on lymphocytes in rheumatic heart valve tissue and its mechanism. Methods Valve tissues of 40 patients undergoing heart valve replacement were collected, including 20 patients in rheumatic heart disease group (without diabetes) and 20 patients in diabetic group (rheumatic heart disease combined with diabetes). In addition, 20 cases of valve tissue from control group were collected. HE staining was used to observe the damage of valve tissue and the area of collagen degeneration. CD4+ T cells, CD8+ T cells, B cells and plasma cells were detected by immunohistochemical staining. Flow cytometry was used to detect the proportion of regulatory T cells (Tregs) in peripheral blood. Results Compared with the rheumatic heart disease group, the damage of valve tissue in the diabetic group was further aggravated, the number of infiltrating inflammatory cells increased, and the area of collagen degeneration was enlarged. Compared with the control group, the number of T cells, CD4+ T cells, CD8+ T cells, B cells and plasma cells in valve tissue of patients with rheumatic heart disease increased significantly. Diabetes mellitus further increased the number of T cells, CD4+ T cells, B cells and plasma cells in valve tissue, but had no significant effect on CD8+ T cells. The proportion of Tregs in the peripheral blood of patients with rheumatic heart disease was significantly reduced. Diabetes mellitus could further reduce the proportion of Tregs. Conclusion The number of T cells, CD4+T cells, B cells and plasma cells in heart valves of rheumatic heart disease patients with diabetes mellitus go up significantly, and Treg ratio goes down.