In this chapter, the principles and selleck chemicals practise of

standardization as applied to assays of coagulation factors are described, with particular emphasis on factor VIII assays, inhibitor assays, and assays for bypassing agents; assays of factor IX, von Willebrand factor (VWF), and factors of the rarer coagulation deficiencies are also considered. “
“Summary.  Inherited diseases of the megakaryocyte lineage give rise to bleeding when platelets fail to fulfill their hemostatic function upon vessel injury. Platelet defects extend from the absence or malfunctioning of adhesion (GPIb-IX-V, Bernard–Soulier syndrome) or aggregation receptors (integrin αIIbβ3, Glanzmann thrombasthenia) to

defects of primary receptors for soluble agonists, secretion from storage organelles, activation pathways and the generation of procoagulant HKI-272 price activity. In disorders such as the Chediak–Higashi, Hermansky–Pudlak, Wiskott–Aldrich and Scott syndromes the molecular lesion extends to other cells. In familial thrombocytopenia (FT), platelets are produced in insufficient numbers to assure hemostasis. Some FT affect platelet morphology and give rise to the ‘giant platelet’ syndromes (e.g. MYH9-related diseases) with changes in megakaryocyte maturation within the bone marrow and premature release of platelets. Diseases of platelet production may also affect other cells and in some cases interfere with development and/or functioning of major organs. Diagnosis of platelet disorders requires platelet function testing, studies often aided by the quantitative analysis of receptors by flow cytometry and fluorescence and electron microscopy. New generation DNA-based procedures including whole exome sequencing offer an exciting new perspective. Transfusion of platelets remains the most common treatment of severe bleeding, management with desmopressin is often used

for mild disorders. Substitute Methisazone therapies are available including rFVIIa and the potential use of thrombopoietin analogues for FT. Stem cell or bone marrow transplanation has been successful for several diseases while gene therapy shows promise in the Wiskott–Aldrich syndrome. This review will discuss the molecular basis, diagnosis and treatment of inherited platelet disorders (IPDs) where abnormalities of platelet function and production give rise to largely mucocutaneous bleeding syndromes of variable intensity [1–5]. The characterization of IPDs has led to novel insights into the complex biology of megakaryopoiesis and platelet production and identified functionally important platelet receptors and intracellular signaling events that have pioneered current antithrombotic therapy.