Platelet survival (PS) time has been studied in patients in a variety of clinical circumstances associated with abnormal numbers of platelets, suspected thrombotic process, or after platelet suppressing drug administration.In conditions with thrombocytopenia, PS may differentiate decreased platelet production (ineffective thrombopoiesis or megakaryocyte hypoplasia) where PS is normal from increased destruction of platelets where PS is shortened. Increased destruction may arise from: extrinsic mechanisms, e.g. immunologic (ITP-SLE-drug reactions) or abnormal surface (diseased endothelium or foreign surface) are associated with short PS, often to extreme degrees; intrinsic platelet defect (Wiskott-Aldrich Syndrome), where autologous PS is shortened and isologous PS is normal.In thrombotic disorders, PS is shortened during active thrombosis and may be chronically shortened in conditions with recurrent thrombosis (homocystinemia, atheroslcerosis, valvular heart disease). The test may prove useful in prognosis (e.g. valvular heart disease patients with shortened platelet survival may have higher risk of embolic events than with normal PS).Only a few platelet suppressing drugs (including sulfinpyrazone and dipyridamole) affect a shortened platelet survival time. These reduce thrombosis in patients with prosthetic heart valves and silastic AV shunts, suggesting PS may identify useful drugs.Thus, PS may differentiate disease conditions associated with abnormal platelets, predict the course of patients at high risk of thrombotic complications, and identify clinically useful platelet suppressing drugs, or serve as a monitor for measuring effects of drug treatment.
Platelet Survival Measurement - Clinical Results.
