Summary
Platelet aggregometry is often used to help diagnose storage pool disease (SPD-reduced
amounts of granule nucleotides) and release defects (abnormal release of granule nucleotides).
The general assumption that normal aggregation patterns are sufficient to rule out
the diagnosis of one of these disorders has been invalidated by the recent publication
of two papers describing patients with clinical bleeding, prolonged bleeding times
and normal aggregation patterns in spite of defective release. The lumiaggregometer
provides a tool for measuring platelet release and aggregation simultaneously. This
paper presents a standardized, reproducible method for the use of the lumiaggregometer
based on a “standard curve”. Data obtained during the development of the procedure
are presented including normal ranges of release at different concentrations of agonists,
release measured in intrinsic disorders as well as in patients on aspirin, and values
for release relative to varying platelet counts. A monoclonal antibody (anti-p24/CD9;
MAb7) which activates platelets similarly to thrombin and may be a useful reagent
for distinguishing SPD and release defects is also introduced.
