Review

There have been many recent potential useful additions to our existing portfolio of platelet function tests. In particular, the development of reliable, sophisticated, but simple to use, whole blood tests (e.g. CSA, PFA-100, Hemodyne, etc.) that mirror physiological conditions provides the ability to screen potential samples rapidly before our existing tests are utilized. These tests should provide us with a rapid, but reliable, means of assessing whether there is a primary haemostatic defect. The in vivo bleeding time may therefore be potentially replaced by simple in vitro tests. Many of the instruments (e.g. Ultegra, PFA-100, CSA, Hemodyne and TEG) have been or will be utilized as point-of-care instruments for assessing bleeding risk or monitoring anti-GpIIb/IIIa or anti-platelet therapy. For the first time therefore, simple platelet function testing may not require the specialized pathology laboratory and will increase cost effectiveness. Flow cytometry now offers a powerful approach to studying a number of different platelet activation markers and will increasingly reveal the true clinical picture of platelet activation in various disorders. Clinically useful flow cytometric assays will also have the potential of being fully automated within existing cell counters. Also, many of the new tests will be able to predict whether certain types of patients exhibit a prothrombotic tendency. For the first time, we will be able to reliably and accurately assess both platelet hypofunction and hyperfunction. With the advent of the millenium, we can now look forward to a completely new approach to both the diagnosis and management of patients with the full spectrum of platelet disorders.