Platelet function testing: practice among UK National External Quality Assessment Scheme for Blood Coagulation participants, 2006

Abstract

The data confirmed the lack of standardisation in methodology employed in different centres. Updated guidelines and standardisation of platelet function assessment are required to facilitate comparability between centres.

96-well plate-based aggregometry

“…As well as requiring expensive and dedicated aggregometers, the technique is labour-intensive and requires specialist training of the individual running the tests. Furthermore, though there are clear International Society on Thrombosis and Haemostasis (ISTH) guidelines for the use of various platelet agonists and their concentrations, adherence to these guidelines is poor and varies with local practice and regulations (6,7). Taking together these variables in assay methodology result in data that is very hard to compare and/or share between different sites and operators.…”

New developments in laboratory diagnosis and monitoring

“…Furthermore, heterogeneity in the biology and laboratory manifestations of platelet function disorders poses additional challenges to standardizing the diagnostic testing [12][13][14][15]. Recent surveys, including the largest worldwide survey of clinical laboratories by the International Society on Thrombosis and Haemostasis [16], have been helpful to identify which aspects of commonly performed platelet function tests, such as light transmission aggregation (LTA), show the greatest deviation in practice [17][18][19]. The lack of standardization in testing has led a number of organizations to develop guidelines and recommendations, using expert opinion and/or systematic reviews of the literature [12,[20][21][22][23].…”

“…Presently, the most common type of diagnostic assay used to investigate a known or suspected platelet function disorder is an assessment of platelet aggregation function, often by LTA [12,16,17]. Although some laboratories perform Ôscreening testsÕ [such as the bleeding time and Platelet Function Analyzer-100 Ò (Siemens/Dade-behing, Marburg, Germany) closure time] [19], neither the bleeding time nor the closure time has sufficient sensitivity to rule out common platelet function disorders [23,25]. LTA has considerable diagnostic utility when performed by rigorously standardized procedures [25,26] with validated reference intervals [27] on samples from individuals referred for bleeding problems.…”

“…Some efforts have focused on defining common practices [16][17][18][19]24] and the heterogeneity in practice stimulated the development of published guidelines from organizations such as the International Society on Haemostasis and Thrombosis and the Clinical and Laboratory Standards Institute [22]. Presently, the most common type of diagnostic assay used to investigate a known or suspected platelet function disorder is an assessment of platelet aggregation function, often by LTA [12,16,17].…”

“…A number of organizations have led efforts to improve and standardize the laboratory assessment of platelet disorders [11,[17][18][19]22,24]. Some efforts have focused on defining common practices [16][17][18][19]24] and the heterogeneity in practice stimulated the development of published guidelines from organizations such as the International Society on Haemostasis and Thrombosis and the Clinical and Laboratory Standards Institute [22].…”