Análise comparativa das metodologias de contagem manual e automatizada de plaquetas em plaquetopenias

Abstract

Introduction: Platelets are fragments of blood cells produced in the bone marrow, megakaryocytes, precursor cells of the myeloid lineage. The main role of platelets in the human body is the formation of hemostatic tampon in response to vascular injury.The decrease in platelets results from different pathophysiological processes, and may be related to bone marrow failure or peripheral platelet destruction. The exam for identification of thrombocytopenia is the hemogram, usually by means of automated haematological analyzers. However, there are disadvantages in the automation method that can not be disregarded. Among them, highlights the factthat it is not possible to observe changes that may cause interference in the results.Thrombocytopenia usually leads to an imbalance in the initial phase of the hemostatic system, which can lead to bleeding. To reverse this condition, the most commonly used therapy in these patients is platelet transfusion. However, platelet concentrate indications should take into account the rational use of blood components due to the risks inherent to the transfusion and the difficult maintenance of the stock because of its short shelf life. For this reason, platelet count for hemostasis defect identification is essential, and it is extremely important to obtain reliable results. Objectives: To evaluate the effectiveness of using the manual platelet counting method considering the correlation with the automated counting, noting the discrepancies in the results obtained and possible therapeutic consequences in patients with thrombocytopenia treated at the Instituto de Base de Brasília. Method: 227 patients were analyzed with platelet counts below 100,000 / μL. The samples were simultaneously submitted to manual counting and counting automated by the Cell Dyn Ruby apparatus. Results: The statistical analysis indicated a regular concordance between the two methods, showing that there is a moderate variability when comparing the two counting methods. Conclusion: The manual methodology can be used in a complementary way to the automated platelet count, and the morphological analysis is fundamental in cases of thrombocytopenia, in order to identify changes that may influence the final result and to add useful information to the diagnosis.