Use Of Non-invasive Examination In Idiopathic Thrombocytopenic Purpura

Idiopathic thrombocytopenic purpura (ITP) is one of the most common acquired bleeding disorders of childhood. And it is an immune mediated disorder in which circulating antiplatelet antibodies target epitopes on the platelet membrane, especially glycoproteins IIb/IIIa and Ib. The antibody-coated platelets are subsequently destroyed by macrophages in the reticuloendothelial system. Under normal conditions, approximately one third of all platelets are contained in the spleen. The life span of a platelet is 9–10 days. Approximately 15,000–45,000 platelets/μL must be produced daily to maintain a steady state. Megakaryocytes, large multinucleated cells found in small numbers in the bone marrow, are responsible for platelet production. Megakaryocytes are derived from pluripotential stem cells influenced by growth factors (interleukin [IL]-3, IL-6, granulocyte-macrophage colony-stimulating factor, IL-11) and a specific thrombopoietin (c-Mpl ligand). Thrombopoietin (TPO) is the most important regulatory protein in the production of platelets. Megakaryocytes and platelets contain the receptor for TPO (c-Mpl). The TPO level increases as platelet count decreases and then decline as the megakaryocyte and platelet mass increases. Endogenous TPO stimulates not only the megakaryocyte growth but also cytoplasmic maturation and platelet release. In the absence of TPO, the megakaryocyte mass may be reduced by as much as 80%. Recombinant TPO can increase the megakaryocytes by Day 3 and the platelets by Day 5. Platelet production can increase six to eight fold within 10 days in response to TPO or to platelet destruction. reticulated platelets(RP)are regarded as the youngest in the circulation. Platelet maturity can be assessed by measuring RP. Platelet RNA is stained with thiazole orange and is analyzed via flow cytometry. Increased reticulated platelets indicate increased platelet production. Compared with normal children and children with leukemia and nutritional megaloblastic anemia, children with ITP had elevated reticulated platelet counts (P < 0.05). Measurement of reticulated platelets may therefore be helpful in assessing children with atypical presentations. Evaluation of a thrombocytopenic patient requires that the cause of the low platelet count is distinguished between defective production or increased utilization-destruction of platelets, a quantitative measurement of platelet production or survival is not routinely available. A simple test for identification of young platelets in peripheral blood, analogous to red blood cell reticulocytes, would solve this problem. Objective TO measure reticulated platelet percent and thrombopoietin in the patients with idiopathic thrombocytopenic purpura(ITP), acute lymphocytic leukemia(ALL),nutritional megaloblastic anemia(MA)and norman control.And to study the mechanisms of thrombocytopenia.To explore significance of reticulated platelet percent and thrombopoietin in the diagnosis of idiopathic thrombocytopenic purpura. Methods Reticulated platelet percent was analyzed via flow cytometry, plasma thrombopoietin was examined by ELISA, platelet and mean platelet volumes were measured by automized machine, megakaryocyte was counted through bone marrow staining. Results Reticulated platelet percent of idiopathic thrombocytopenic purpura patients'group were higher than any other groups, thrombopoietin of this group was close to control group,increased megakaryocytosis of this group was associated with larger mean platelet volumes and higher reticulated platelet percent. Conclusion Examination of reticulated platelet percent and thrombopoietin is helpful to classify patients with thrombocytopenia into different categories and may be of a value in the diagnosis of idiopathic thrombocytopenic purpura.