Summary
Platelet function testing is essential for the diagnosis of congenital/acquired bleeding
disorders and may be useful for the prediction of surgical bleeding. Nowadays there
is also much interest in monitoring the efficacy of anti-platelet therapy and measuring
platelet hyper-function. However, this often presents clinical laboratories with significant
challenges as platelet function tests are complex, poorly standardized, time consuming
and quality assurance is not straightforward. There are also few comprehensive modern
guidelines available and many recent published surveys have revealed poor standardization
between laboratories.
Up until the late 1980’s the traditional clinical platelet function tests that were
available were the bleeding time (BT), light transmission (LTA) and whole blood aggregometry
(WBA) and various biochemical assays. These were also usually performed within specialized
research and clinical laboratories. Since the last BCSH guidelines were published
in 1988 a variety of new platelet function tests have become available. These include
flow cytometry and an ever increasing choice of new commercial instruments. Although
the potential clinical utility of the new assays is emerging some have not yet entered
into routine clinical practice. It is encouraging that a number of standardization
committees (e. g. CLSI, BCSH and ISTH Platelet Physiology SSC) are now beginning to
produce new platelet function testing guidelines and this will hopefully improve clinical
practice, quality assurance and result in less variability between different laboratories.