Discussion On Changes In Immunity-related Indexes Of Idiopathic Thrombocytopenic Purpura And The Clinical Significance

Objective: (1)To test the expression of anti-GPIIb/Ⅲa and anti-GPIb/Ⅸspecific autoantibodies and changes in T lymphocyte subsets in patients with ITP(idiopathic thrombocytopenic purpura) and to analyze the correlation between the specific autoantibodies and the platelet count, discussing the role played by the related factors in pathogenesis of ITP. (2) To test the changes of concentration of TPO in the serum and the percentage of reticulated platelet of peripheral blood in patients with ITP, analyze the correlation between their changes and the platelet count and discuss their role in diagnosis and pathogeny of ITP.Method: (1)Expression of anti-GPIIb/Ⅲa and anti-GPIb/Ⅸspecific autoantibodies and changes in T lymphocyte subsets in 52 patients with ITP and 24 healthy controls were tested with monoclonal antibody immobilization of platelet antigens assay (modified MAIPA) and flow cytometry(FCM) respectively. (2) The changes of concentration of TPO in the serum and the percentage of reticulated platelet of peripheral blood in 50 patients with ITP and 30 healthy controls were tested by means of enzyme-linked immunosorbent assay (ELISA) and FCM respectively. At the same time, PLT (platelet count) was detected with hemocytoanalyser and megakaryocyte number of bone marrow was counted by hand.Result: (1)Platelet count (37.15±22.4)×109/L in patients with ITP was much less than that in healthy controls(223.17±43.6)×109/L (P<0.05); autoantibodies optical densities of anti-GPIIb/Ⅲa and anti-GPIb/Ⅸ[(0.43±0.06),(0.40±0.04) respectively] were all much higher than that in healthy controls[(0.34±0.02),(0.32±0.02)respectively] (P<0.05); there was an inverse correlation between the platelet count and the expression of each autoantibody in patients with ITP; correlation coefficient were respectively r=0.30 and r =0.31(P<0.05);in terms of changes in T lymphocyte subsets, the percentage of CD3 + T Lymphocyte(60.06±12.08)% in patients with ITP was obviously lower than that in healthy controls (69.89±5.56)% (P<0.05);the percentage of CD4+ T Lymphocyte (27.74±9.67)% was lower than that in healthy controls (35.87±4.07)% (P<0.05);and the ratio of CD4+/ CD8+ in patients with ITP (1.11±0.34)% was obviously lower than that in healthy controls (1.64±0.32)% (P<0.05);but the percentage of CD8+ T Lymphocyte (31.12±12.49)% was much higher (22.53±4.12)% than that in healthy controls (P<0.05);(2)The concentration of TPO in the serum (77.73±40.4) pg/ml of patients with ITP was higher compared with that in healthy controls (75.69±37.5) pg/ml (P>0.05), no significance of difference and no obvious correlation between the concentration of TPO in the serum and the platelet count and megakaryocyte count of bone marrow respectively(P<0.05). Reticulated platelet percentage (28.11±14.08)% in patients with ITP is obviously higher than that in healthy controls (8.19±2.46)% with significance of difference (P<0.05). There was inverse correlation between reticulated platelet percentage in patients with ITP and their platelet count. The correlation coefficient is r=-0.416 (P<0.05).Conclusion: (1) Expression of anti-platelet (GPⅡb/Ⅲa and GPIb/Ⅸ) specific autoantibodies could be used as one of the lab indexes for diagnosing ITP and has a certain clinical value in the diagnosis of ITP. (2) There was an inverse correlation between the platelet count and the optical density (A) of each specific autoantibody in patients with ITP, which indicates the increase of anti-platelet specific autoantibody maybe the main reason of accelerating the destruction of the platelets. (3) Pathogenesis of ITP involves the disequilibrium of proportion of T lyphocyte subsets and the disorder of their function:disequilibrium of immune adjustment of T lyphocyte made Th cell insufficient and Ts/Tc cell excessive relatively, which caused immunity injure of cells. (4) The disorder of T lyphocyte subsets played a critical role in the pathogenesis of ITP. To regulate the balance of T lymphocyte subsets may be a new approach to the treatment of autoimmune diseases such as ITP. (5) There is no significance of difference between the concentration of TPO in the serum in patients with ITP and that in healthy controls. The test of the concentration of TPO in the serum has important significance for the study of regulation mechanism of the platelet generation and the diagnosis of ITP. But the changes of the concentration of TPO, its regulatory mechanism and the exact clinical significance need to be studied further. (6) Reticulated platelet percentage in the peripheral blood of patients with ITP is obviously higher than that in healthy controls and there was inverse correlation between it and the platelet count. Therefore, reticulated platelet percentage can be an indicator of predicting the recovery state of the platelets in the treatment of ITP patients and has the importance clinical significance in differentiating and diagnosing diseases caused by the decrease of platelets.