
British Journal of Medical & Health Sciences (BJMHS) Vol. 2 Issue 4, April - 2020 Comparison Of Platelet Count By Automated And Manual Methods, A Study And Review Of Literature In A Medical College Hospital In Kashmir 1Dr Jangbhadur Singh Associate Professor, Pathology,2Sawaira Parvaiz Msc haematology Lab. Tec.3Dr Afiya Shafi, 4Dr Nadia Jeelani,5Dr Mabruka Jeelani SKIMS Medical College . Srinagar, Kashmir, India. Abstract to 8 cuµ in volume. Normally, platelets are of several shapes viz. Spherical or rod shaped and become oval Introduction: Estimation of platelet counts is of or disc shaped when inactivated, arising from the prime importance in clinical practice as well as in fragmentation of megakaryocytes. Megakaryocytes certain diseases.Automated analysers commonly are giant cells in the bone marrow, form platelets by used for platelet analysis may produce erroneous pinching off and extruding pieces of cytoplasm. results in presence of particles or light scatter like fragmented red blood cells and giant platelets and platelet clumps, so alternative methods like using chamber counting and peripheral blood smear examination can be used for validation. Aims and Objectives: Comparison of platelet counts by three methods: 1. Automatic analyser. 2. Manual platelet count using counting chamber and 3. Traditional method , counting average platelets per ten high power fields[100X] and multiplying the same by 15000. Methods: Four hundred Ethylene Diamine tetra-acetic Acid (ED TA) samples were analysed over a period of six months .Statistical analysis was done by using microsoft software. Descriptive statistics like mean and percentage were used for data interpretation. Sensitivity and specificity of the manual methods was compared with that of automated analyzesr. Results: The mean platelet count by Hemostasis, the process of stopping bleeding, is automated method was 1.70/µl. The mean platelet the primary function of platelets. To accomplish this, count by Neubauer chamber is 1.77/µl and mean platelets contain lysosomes (chemicals capable of platelet count by PBF was 1.81/µl. The P value for breaking down other substances), clotting factors, and automated versus Neubauer chamber was 0.57 and a growth factor that stimulates healing. Traveling in for automated method versus PBF was 0.87 the circulation, platelets join with other blood Suggesting that there was no significant variation in components to limit blood loss. Platelets may also the platelet count between the manual methods when help maintain the integrity of the vascular lining and compared with automated analyzer. Conclusion stimulate proliferation of vascular smooth muscle. :Platelet count by manual method using chamber for counting as well as by traditional method using Blood coagulation is a complex process. Activated peripheral blood smears for platelet counting are by factors at the site of an injured blood vessel, validated as alternative and reliable methods of platelets aggregate (collect) to form a plug, change platelet counting. shape, discharge their granules, and initiate the generation of thrombin, an enzyme that converts Keywords—Platelet count; automated analyser; fibrinogen to fibrin. Thrombin causes them to become peripheral blood smear; thrombocytes, sticky and adhere irreversibly to each other, as well as I. INTRODUCTION to the break in the vessel wall. The granules attract more platelets, and thrombin begins formation of a Platelets or thrombocytes are the formed elements true clot with a net of fibrin. of blood. Platelets are small colorless, non nucleated and moderately refractive bodies, these formed Platelets, besides being acute phase reactants, are also influenced by the patient`s health and elements of blood are considered to be the fragments [1, 2]. of cytoplasm. Platelets are 2 to 4 µ in diameter and 7 nutritional status Sometimes the platelets have www.jmhsci.org BJMHS450083 177 British Journal of Medical & Health Sciences (BJMHS) Vol. 2 Issue 4, April - 2020 dumbbell shape, comma shape, cigar shape or any normal or prolonged bleeding time but defective clot other unusual shape. Inactivated platelets are without retraction. processes or filopodia and the activated platelets Giulio Bizzozero, an Italian pathologist is credited develop processes or filopodia. Platelet is constituted with identifying platelets as an important component of by cell membrane, microtubules, and cytoplasm. blood and their essential involvement in the Platelets are inactive and execute their actions mechanism of blood clotting at the end of the only when activated. Activated platelets immediately nineteenth century [3]. It is a well known fact that an release many substances. This process is known as accurate and reproducible platelet counts are of platelet release reaction. Platelets are responsible for utmost importance in day-to-day clinical practice formation of intrinsic prothrombin activator. This aiding not only in diagnosis but also in the treatment substance is responsible for the onset of blood and prognostication of a wide variety of diseases [4]. clotting. In the blood clot, blood cells including Severe thrombocytopenia can present as internal and platelets are entrapped in between the fibrin threads. external bleeding which maybe fatal and require Cytoplasm of platelets contains the contractile emergency platelet transfusion. At the other extreme, proteins, namely actin, myosin and thrombosthenin, thrombocytosis can cause thrombotic events [5]· In which are responsible for clot retraction. Platelets infections like malaria and dengue-with accelerate the heamostasis. Platelets secrete 5-HT thrombocytopenic patients facing the potential risk of which causes the constriction of blood vessels. Due to bleeding-an accurate count is imperative. Platelet adhesive property, the platelets seal the damage in count is also one of the parameters to assess the blood vessel like capillaries. By formation of severity of dengue [6]. It is also important to temporary plug, the platelets seal the damage in blood prognosticate patients undergoing cytotoxic therapy vessels. Platelet-derived growth factor formed in for hematological malignancies. Studies have shown cytoplasm of platelets is useful for the repair of the that platelet count is often reduced than normal in endothelium and other structures of the ruptured patients of Nonalcoholic fatty liver disease (NAFLD), blood vessels. thereby providing a supportive indicator in addition to liver biopsy in these patients. At present, platelet Platelet disorders occur because of pathological count is also used for prognostication of fibrosis and variation in platelet count and dysfunction of platelets. [7]. cirrhosis of the liver Various principles of doing Platelet disorders are: Thrombocytopenia, automated platelet counts are impedance, optical thrombocytosis, thrombocythemia, Glanzmann’s scattering, optical fluorescence, and immunologic flow thrombasthenia. cytometry. The manual phase contrast microscopy Thrombocytopenia is the decrease in platelet method, although considered the gold standard was count. It leads to thrombocytopenic purpura ; it is a abandoned as it was time-consuming and not precise disorder characterized by prolonged bleeding time. at low counts. However, clotting time is normal. Characteristic Immunological flow reference method also known feature of this disease is spontaneous bleeding under as the RBC platelet ratio method replaced the manual the skin from ruptured capillaries. It causes small tiny phase contrast microscopy method as the hemorrhagic spots in many areas of the body. The international decade, which has led to greater hemorrhagic spots under the skin are called purpuric precision in platelet counting and has resulted in its spots (purple colour patch like appearance). That is [8]. extensive use in laboratories worldwide. A few why this disease is called purpura. Thrombocytopenia limitations of estimating platelet counts on Leishman is caused due to many conditions like acute infections, stain smears are improper staining and stain artifacts. acute leukemia, aplastic and pernicious anemia, [9] To overcome this, study by Uma Shankar et al has chickenpox, smallpox, splenomegaly, scarlet fever, shown that even the unstained peripheral smears typhoid, tuberculosis, purpura, Gaucher’s disease. prepared from fresh blood can be used to evaluate a Thrombocytosis is the increase in platelet count. platelet counts. However micro platelets are difficult to Thrombocytosis can occur due to conditions like appreciate and large platelets resemble WBCs on allergic conditions, asphyxia, hemorrhage, bone unstained smears which must be considered [10]. A fractures, surgical operations, splenectomy, rheumatic major factor contributing to the accuracy of platelet fever, and trauma. counts is the duration of sample storage post collection. The standard guidelines state that Thrombocythemia is the condition with persistent processing of hematological samples should be done and abnormal increase in platelet count. within six to eight hours of collection, to avoid Thrombocythemia occurs due to many conditions like variations and errors in reporting the different carcinoma, chronic leukemia, Hodgkin’s disease. hematological parameters [9, 11]. A study by Jain et al Glanzmann’s thrombasthenia is an inherited has shown that platelet counts done on automated hemorrhagic disorder caused by structural or analyzer s showed an unacceptable bias even within functional abnormality of platelets. It leads to less than
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