WHO/DIL/LAB/99.1 Rev.2 Original :ENGLISH Distr.:GENERAL WORLD HEALTH ORGANIZATION USE OF ANTICOAGULANTS IN DIAGNOSTIC LABORATORY INVESTIGATIONS 2002 WHO/DIL/LAB/99.1 Rev.2 Page 2 © World Health Organization This document is not a formal publication of the World Health Organization (WHO), but all rights are reserved by the Organization. The document may, however, be freely reviewed, abstracted, reproduced or translated, in part or in whole, but not for sale or for use in conjunction with commercial purposes. The views expressed by named authors are solely the responsibility of those authors. WHO/DIL/LAB/99.1 Rev.2 Original :ENGLISH Distr.:GENERAL USE OF ANTICOAGULANTS IN DIAGNOSTIC LABORATORY INVESTIGATIONS & Stability of blood, plasma and serum samples Contributors: G. Banfi, Milan, Italy H. Kitta, Usingen, Germany K. Bauer, Vienna, Austria D. Klahr, Tuttlingen, Germany W.Brand, Nümbrecht, Germany D. Kolpe, Nümbrecht-Elsenroth, Germany M.Buchberger, Kremsmünster, Austria J. Kukuk, Limburg, Germany A. Deom, Geneva, Switzerland T. Kunert-Latus, Leuven, Belgium W.Ehret, Augsburg, Germany* M.Lammers, Marburg, Germany W.D. Engel, Mannheim, Germany E.A. Leppänen, Helsinki, Finland F. da Fonseca-Wollheim, Berlin, Germany* P. Mikulcik, Fernwald, Germany C.G. Fraser, Dundee, Scotland S. Narayanan, New York, USA V.J. Friemert, Deisenhofen, Germany M. Neumaier, Hamburg, Germany S. Golf, Giessen, Germany M.A. Peça Amaral Gomes, Lisbon, Portugal H.Gross, Hanau, Germany R. Probst, Munich, Germany W.G. Guder, München ,Germany** Y. Schmitt Darmstadt, Germany* G. Gunzer, Clare, Ireland O. Sonntag, Neckargemünd, Germany P. Hagemann, Zürich, Switzerland G. Töpfer, Görlitz, Germany* W. Heil, Wuppertal, Germany* R. Weisheit, Penzberg, Germany J. Henny, Nancy, France H. Wisser, Stuttgart, Germany* R. Hinzmann, Krefeld Germany B. Zawta, Mannheim, Germany* P. Hyltoft Persen, Odense, Denmark R. Zinck Mannheim, Germany G. Hoffmann, Grafrath, Germany ------------------------------------------- A. Kallner, Stockholm, Sweden * Member of working group A. Karallus, Heidelberg, Germany ** Chairman of working group WHO/DIL/LAB/99.1 Rev.2 Page 4 WHO/DIL/LAB/99.1 Rev. 2 Page 2 The WHO document "Use of Anticoagulants in Diagnostic Laboratory Investigations" (WHO/DIL/LAB/99.1 Rev. 1) received a surprising resonance and experts around the world provided many additional observations. This information has been included in the 2nd revision of the document. The document provides an extensive summary of observations on the effects of anticoagulants in blood, plasma and serum. Information on the effects of haemolysis, hyperbilirubinaemia and hyperlipoproteinaemia on measurement procedures has been added. WHO is grateful for the efforts made by the group of experts in collecting all the information necessary for this revised version. Geneva, 15 January 2002 WHO/DIL/LAB/99.1 Rev.2 Page 3 Contents 1 Serum, Plasma or Whole Blood? Which Anticoagulants to Use? 5 1.1 Definitions.............................................................................................................................................5 1.1.1 Whole blood............................................................................................................................5 1.1.2 Plasma ......................................................................................................................................5 1.1.3 Serum........................................................................................................................................5 1.1.4 Anticoagulants ........................................................................................................................5 1.2 Plasma or serum?..................................................................................................................................6 1.2.1 Advantages of using plasma .................................................................................................6 1.2.2 Disadvantages of plasma over serum..................................................................................6 1.2.3 Analytical samples in the serological diagnosis of infectious diseases ........................7 1.3 Recommendations................................................................................................................................7 1.3.1 Sample collection and transport time ..................................................................................7 1.3.2 Centrifugation.........................................................................................................................7 1.3.3 Storage .....................................................................................................................................8 1.3.4 Evaluation of new analytical procedures ...........................................................................8 2 The Optimal Sample Volume 8 2.1 Definition...............................................................................................................................................8 2.2 Recommendations................................................................................................................................9 2.2.1 Measures which can help to reduce the required blood volume.....................................9 2.2.2 Documentation........................................................................................................................9 3 Analyte Stability in Sample Matrix 9 3.1 Stability and Instability .....................................................................................................................10 3.2 Quality assurance of the time delay during the pre-analytical phase........................................10 3.2.1 Transport time .......................................................................................................................10 3.2.2 Pre-analytical time in the laboratory.................................................................................10 3.2.3 Documentation......................................................................................................................10 3.2.4 Actions to be taken when the maximum permissible pre-analytical times are exceeded ................................................................................................................................10 4 The Haemolytic, Icteric and Lipaemic Sample 11 4.1 Definition of a clinically relevant interference..............................................................................11 4.2 General recommendations................................................................................................................11 4.2.1 Documentation of interferences.........................................................................................11 4.2.2 Detection of a potentially interfering property and handling of sample and request............................................................................................................................12 4.2.3 Reporting results ..................................................................................................................12 4.3 The haemolytic sample and the effect of therapeutic haemoglobin derivatives......................12 4.3.1 Haemolysis ............................................................................................................................12 4.3.2 Haemoglobin based oxygen carriers used as blood substitutes ...................................12 WHO/DIL/LAB/99.1 Rev. 2 Page 4 4.3.3 Detection and measurement of haemoglobin in serum or plasma ...............................13 4.3.4 Distinction between in-vivo haemolysis and in-vitro haemolysis .............................13 4.3.5 Mechanisms of interference by haemolysis .....................................................................13 4.3.6 Means to avoid haemolysis and its interferences ...........................................................14 4.3.7 Reaction upon the receipt of haemolytic samples ..........................................................14 4.4 The Lipaemic Sample ........................................................................................................................15 4.4.1 Definition...............................................................................................................................15 4.4.2 Causes of lipaemia (turbidity)............................................................................................15 4.4.3 Identification and quantification of lipaemia...................................................................15 4.4.4 Mechanisms of the interference by lipaemia on analytical methods ..........................15 4.4.5 Means to avoid lipaemia and interferences caused by turbidity ..................................16 4.4.6 Recommendation..................................................................................................................17 4.4.7 Test of interference by lipaemia.........................................................................................17 4.5 The icteric sample ..............................................................................................................................17 4.5.1 Appearance of different bilirubin species ........................................................................17 4.5.2 Mechanisms of bilirubin interference...............................................................................17 4.5.3 Detection