The role of B-1 lymphocytes in antitumor immunity in patients with gastric cancer

Introduction. B1-lymphocytes are a subpopulation of B-cells, the proportion of which in the spleen accounts for 5 % of the total number of B-cells. B1-lymphocytes predominantly secrete IgM, which plays an important role in the induction of tumor cell apoptosis. Splenec tomy for the purpose of adequate lymph node dissection in gastric cancer causes marked and prolonged immunological disorders. It primarily affects the B1a-lymphocyte subpopulation, which provides a thymus-independent immune response.

Objective. To study the features of the B-cell component of immunity in patients with gastric cancer.

Materials and methods. The subpopulation composition of B-lymphocytes of peripheral blood of gastric cancer patients undergoing sur gical treatment using flow cytometry (Facs Can, Lysys II and FacsCanto II programs, Facs Diva program) was analyzed. Cells were stained simultaneously with three monoclonal antibodies labeled with different fluorochromes.

Results. The data obtained demonstrate a violation of the composition of B-cell subpopulations. In the group of patients with standard D2 lymph node dissection and splenectomy at the preoperative stage and three months after surgery, a significant correlation was found between the relative number of B lymphocytes (p = 0.018), CD5 + B lymphocytes (p = 0.012) and the number of CD19 + CD38 + cells (p = 0.035). In addition, after surgical treatment, the percentage of CD5 + B-lymphocytes increased significantly from 12.9 to 21.8 %, while the total number of CD19 + lymphocytes and CD19 + CD21 + cells decreased.