Platelet Dysfunction- What a Physician

Platelet functional disorders are on the increase. The basic platelet functions are a continuous process starting when the vessel wall is injured. The three phases are 1 Initiation 2 Extension and 3 consolidation After these phases, a stable platelet plug is formed. Disorders of platelet function arise due to hereditary and acquired defects in the various steps of these functional phases. Acquired platelet dysfunctions are much more common than hereditary disorders. The usual causes are drugs especially anti platelet drugs, uremia, liver diseases, diabetes mellitus, cardiac bypass, hematological disorders like MDS, AML, paraproteinemias and myeloproliferative disorders. Common hereditary disorders are Bernard-Soulier syndrome, Glansmann thrombasthenia and storage pool disorders. Advanced investigations like platelet aggregation studies and flow cytometry are necessary for accurate diagnosis of hereditary platelet disorders. Treatment of these disorders is mainly symptomatic. Platelet transfusions are life saving in hereditary disorders but may induce antibodies if repeatedly used. For acquired disorders the offending drugs should be stopped. The diseases responsible for the platelet dysfunction should be effectively treated. Symptomatic treatment with red cell transfusion and platelet transfusion should be given. In future one may see a significant improvement in early diagnosis and medical management of inherited platelet disorders with improvement in platelet function measurements and proteomic (study of protein and their structure) approaches. IntroductIon Platelet disorders are very common in clinical practice. Quantitative platelet abnormalities (various causes of thrombocytopenia) are much more common than qualitative abnormalities (platelet functional abnormalities). Sometimes they can co exist. Basic understanding of the platelet functions is necessary to understand and evaluate the disorders of platelet dysfunction. When there is a blood vessel injury the circulating platelets interact with a number of components of extra cellular matrix particularly collagen. This will lead to a series of receptor ligand interactions finally leading to the formation of a stable platelet plug or thrombosis. These interactions are a continuous process and consist of three phases.