Is automated platelet counting still a problem in thrombocytopenic blood?
Keywords:
Platelet counting, Automatic counters, Transfusion, Thrombocytopenic patientsAbstract
CONTEXT: Reliable platelet counting is crucial for indicating prophylactic platelet transfusion in thrombocytopenic patients. OBJECTIVE: To evaluate the precision and accuracy of platelet counting for thrombocytopenic patients, using four different automated counters in comparison with the Brecher & Cronkite reference method recommended by the International Committee for Standardization in Hematology (ICSH). TYPE OF STUDY: Automated platelet counting assessment in thrombocytopenic patients. SETTING: Hematology Laboratory, Hospital do Servidor Público Estadual de São Paulo, and the Hematology Division of Instituto Adolfo Lutz, São Paulo, SP, Brazil. MAIN MEASUREMENTS: Brecher & Cronkite reference method and four different automated platelet counters. PARTICIPANTS: 43 thrombocytopenic patients with platelet counts of less than 30,000/µl RESULTS: The ADVIA-120 (Bayer), Coulter STKS, H1 System (Technicom-Bayer) and Coulter T-890 automatic instruments presented great precision and accuracy in relation to laboratory thrombocytopenic samples obtained by diluting blood from normal donors. However, when thrombocytopenic patients were investigated, all the counters except ADVIA (which is based on volume and refraction index) showed low accuracy when compared to the Brecher & Cronkite reference method (ICSH). The ADVIA counter showed high correlation (r = 0.947). However, all counters showed flags in thrombocytopenic samples. CONCLUSION: The Brecher & Cronkite reference method should always be indicated in thrombocytopenic patients for platelet counts below 30,000 plt /µl obtained in one dimensional counters.
Downloads
References
- 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.
