Platelet aggregation

Abstract

Platelet aggregometry is an important technique for assessing platelet function for diagnostic and research purposes. Platelet aggregometry remains the most important, established platelet function test for evaluating platelet function for diagnostic purposes. Light transmittance platelet aggregometry and whole blood aggregometry are more popular methods for testing platelet aggregation responses than flow cytometry and platelet counting methods. In recent years, there have been considerable efforts to improve and standardize the assessment of platelet function by aggregometry. The focus has been on light transmittance platelet aggregometry as there are many more publications on this method, and more information on how the test performs for the diagnosis of bleeding disorders. Guidelines are now available on when and how to perform aggregometry (including choices of agonists, and final agonist concentrations), and how to interpret the test findings for diagnostic purposes. This chapter focuses on the principles and uses of aggregometry, with emphasis on using the test for diagnosing platelet function disorders, with proper quality control of all steps from sample procurement, processing, analysis to interpretation and reporting. Examples are provided of abnormal aggregation responses due to a variety of clinical conditions, including rare and more common platelet function disorders that impair aggregation responses. Interesting data continues to emerge on the causes of common platelet function disorders that impair aggregation responses, a number of which reflect mutations in genes encoding transcription factors that are important for generating normal, functional platelets.