Evaluation of Immune Status Before and After Splenectomy in Immune Thrombocytopenia Patients

A total of 30 ITP patients will be enrolled in the study. These patients should fail to have sustained response to multiple first- and second-line treatments of ITP and agree to have splenectomy. Before splenectomy, these patients will be reassessed and still diagnosed with ITP.Their platelet level will be raised to a safe state before surgery, and the laparoscopic splenectomy will be performed in Tianjin People's Hospital. The investigators plan to take 20ml of peripheral blood (PB) of these patients at 6 time points, including 1 day before surgery, 1 week, 1 month, 3 months, 6 months, and 12 months after surgery, and take a small amount of spleen tissue during surgery. 18 age- and gender- matched healthy donor will also be enrolled as controls and taken 20ml of peripheral blood. The investigators also plan to take splenic tissue from 10 patients who have splenectomy due to Hereditary spherocytosis or trauma. And then the investigators will do the experiments step by step. 1, Isolation of peripheral blood and splenic mononuclear cells;2, Detection of the percentage of cell population;3, Activation and proliferation of B lymphocyte; 4, Activation and proliferation of T lymphocyte;5,Apoptosis of platelets by cytotoxic T cells;6,Phagocytosis of platelets by macrophages in spleen;7,Enzyme-linked immunosorbent assay (ELISA) for cytokines.