Is automated platelet counting still a problem in thrombocytopenic blood?
Palavras-chave:
Contagem, Plaquetas, Automação, Transfusão, PlaquetopeniaResumo
CONTEXTO: A contagem de plaquetas confiável é de grande importância para avaliar a necessidade da transfusão profilática em pacientes plaquetopênicos. OBJETIVO: Avaliar, em amostras plaquetopênicas, a precisão e exatidão da contagem de plaquetas em quatro contadores automáticos em comparação com método de referência de Brecher & Cronkite recomendado pelo Comitê Internacional de Estandardização em Hematologia. TIPO DE ESTUDO: Avaliação da contagem automatizada de plaquetas em pacientes trombocitopênicos. LOCAL: Hospital do Servidor Público Estadual (São Paulo - SP). Instituto Adolfo Lutz. PARTICIPANTES: 43 pacientes trombocitopênicos com contagens de plaquetas inferiores a 30.000/µL. VARIAVEIS ESTUDADAS: Método de Brecher & Cronkite como padrão de referência e quatro contadores automáticos. RESULTADOS: Os contadores automáticos ADVIA-120 (Bayer), Coulter STKS, H1 System (Technicom-Bayer) e Coulter T-890 demonstraram boa precisão e exatidão em amostras plaquetopênicas obtidas em laboratório de hematologia a partir de amostras normais. Apenas o ADVIA-120, que utiliza dois princípios de contagem (volume e índice de refração), demonstrou boa correlação com o método de referência recomendado pelo Comitê Internacional de Estandardização em Hematologia (ICSH, 1984/1988) para as amostras dos pacientes trombocitopênicos (r = 0,947). Entretanto, todos os aparelhos pediram nova contagem de plaquetas (flags) para as amostras trombocitopênicas. CONCLUSÃO: A utilização do método de referência de Brecher Cronkite deve ser uma conduta rotineira e indispensável em todos pacientes trombocitopênicos com contagens abaixo de 30,000 plaq /µl obtidas em contadores que utilizam-se apenas do volume como princípio de contagem.
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Referências
- Ross DW, Bentley SA. Evaluation of an automated hematology system (Technicon H-1). Arch Pathol Lab Med 1986;110(9):803-8.
- Cornbleet PJ, Myrick D, Judkins S, Levy R. Evaluation of the CELL-DYN 3000 differential. Am J Clin Pathol 1992;98(6):603-14.
- Arkin CF. Quality control and standardization in the hematology laboratory. In: Bick RL, editor. Hematology: clinical and labo- ratory practice. St Louis: Mosby; 1993.p.17-37.
- Dickerhoff R, Von Ruecker A. Enumeration of platelets by multiparameter flow cytometry using platelet-specific antibod- ies and fluorescent reference particles. Clin Lab Haematol 1995;17(2):163-72.
- Jones RG, Faust AM, Matthews RA. Quality team approach in evaluating three automated hematology analyzers with five-part differential capability. Am J Clin Pathol 1995;103(2):159-66.
- Ault KA. Platelet counting: Is there room for improvement? Lab Hematol 1996;2:139-43.
- Mayer K, Chin B, Magnes J, Thaler HT, Lotspeich C, Baisley A. Automated platelet counters: a comparative evaluation of latest instrumentation. Am J Clin Pathol 1980;74(2):135-50.
- Ross DW, Ayscue L, Gulley M. Automated platelet counts: accuracy, precision, and range. Am J Clin Pathol 1980;74(2):151-6.
- Kjeldsberg CR. Principles of hematologic examination. In: Lee GR, Bithell TC, Foerster J, et al., editors. Wintrobe’s Clinical Hematology. 9th ed. Philadelphia: Lea & Febiger; 1993.p.11-12.
- Kunicka JE, Fischer G, Murphy J, Zelmanovic D. Improved platelet counting using two-dimensional laser light scatter. Am J Clin Pathol 2000;114:283-9.
- Hanseler E, Fehr J, Keller H. Estimation of the lower limits of manual and automated platelet counting. Am J Clin Pathol 1996;105(6):782-7.
- Klee GG. Performance goals for internal quality control of multichannel haematology analysers. Clin Lab Haematol 1990;12(Suppl 1):65-74.
- Rowan RM. Platelet counting and the assessment of platelet function. In: Keopke JA, editor. Practical Laboratory Hematology. New York: Churchill Livingstone; 1991.p.157-70.
- Bode AP. The use of flow cytometry in the study of blood plate- lets. In: Riley RS, Mahin EJ, Ross W. Clinical applications of flow cytometry. New York: Igaku-Shoin; 1993.p.613-33.
- Stanworth SJ, Denton K, Monteath J, Patton WN. Automated counting of platelets on the Bayer ADVIA 120 analyser. Clin Lab Haematol 1999;21(2):113-7.
- Lawrence JB, Yomtovian RA, Dillman C, et al. Reliability of automated platelet counts: comparison with manual method and utility for prediction of clinical bleeding. Am J Hematol 1995;48(4):244-50.
- Gil-Fernández JJ, Alegre A, Fernández-Villalta MJ, et al. Clini- cal results of a stringent policy on prophylac-tic platelet trans- fusion: non-randomized comparative analysis in 190 bone mar- row transplant patients from a single institution. Bone Marrow Transplant 1996;18(5):931-5.
- Sherrill JS, Corash L, Shiffer C, et al. Newer approaches to platelet transfusion therapy. In: Transfusion Medicine Educa- tion program of The American Society of Hematology, Orlando, 1996. Proceedings. Philadelphia: ASH; 1996.p.119-31.
- Beutler E. Platelet transfusions: the 20,000/microL trigger. Blood 1993;81(6):1411-3.
- Finazzi G. Prophylactic platelet transfusion in acute leukemia: which threshold should be used. Haematologica 1998;83(11):961-2.
- Navarro JT, Hernández JA, Ribera JM, et al. Prophylactic platelet transfusion threshold during therapy for adult acute myeloid leukemia: 10,000/microL versus 20,000/microL. Haematologica 1998;83(11):998-1000.
- Gmür J, Burger J, Schanz U, Fehr J, Schaffner A. Safety of stringent prophylactic platelet transfusion policy for patients with acute leukemia. Lancet 1991;338(8777):1223-6.
- Consensus Development Conference. Platelet transfusion therapy. JAMA 1987;257(13):1777-80.
- Brecher G, Cronkite EP. Morphology and enumeration of hu- man blood platelets. J Appl Physiol 1950;3:365-77.
- Brecher G, Schneiderman MA, Cronkite EP. The reproducibil- ity and consistency of the platelet count. Am J Clin Pathol 1953;23:15-26.
- England JM, Rowan RM, van Assendelft OW, et al. Protocol for evaluation of automated blood cell counters. International Committee for Standardization in Haematology (ICSH). Clin Lab Haematol 1984;6(1):69-84.
- Platelet counting by the RBC/platelet ratio method: A refer- ence method. Am J Clin Pathol 2001;115(3):460-4.
- Tycko DH, Metz MH, Epstein EA, Grinbaum A. Flow- cytometric light scattering measurement of red blood cell vol- ume and hemoglobin concentration. J Applied Optics 1985;24:1355-65.
- Technicon H*1 System Information Bulletin. Technical Publica- tion N0 TN8-8588-22. Tarrytown, NY: Technicon Instrument Corp; December, 1988:3-4.
- Technicon H*1 System: Operator’s Guide. International Division ed. Tarrytown, NY: Technicon Instrument Corp; 1985: 2/56-57.
- Coulter STKS Analyser with reticulocyte analysis: product ref- erence manual n. 4237182B. Miami: Coulter; 1995.
- Coulter T Series with differential capabilities: product refer- ence manual n. 4235880C. Miami: Coulter; 1993.
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