This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
[{'content': 'Which of the following is true regarding Von Willebrand disease? \nSelect and explain. \nA. Type 1 & 3 are associated with quantitative defects in vWF, B. Normal platelet count, C. Desmopressin stimulates release of VWF, D. All of the above.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ref. Robbins Pathology. 9th edition. Page. 667\n\xa0\nVon Willebrand’s factor is a\xa0glycoprotein\xa0made in\xa0epithelial cells\xa0and megakaryocytes which:\n\nActs as a\xa0bridging molecule\xa0between\xa0platelets\xa0and the\xa0sub-endothelium\nHelps platelets bind to each other\nIs a\xa0carrier of factor VIII,\xa0helping to prevent its breakdown in the circulation\xa0\n\n\xa0\nTypes of Von Willebrand’s disease:\n\nType 1\n\nDecreased quantity\xa0of VWF\xa0\nMild to moderate bleeding\n\n\nType 2\xa0(several subtypes exist)\xa0\n\t\nQualitative defect\xa0- abnormal types of VWF\xa0\n\n\nType 3\xa0\n\nTrace of VWF\nAutosomal recessive\xa0\nSevere bleeding disorder\n\n\n\nPresentation\xa0includes\n\nProlonged bleeding\xa0after injury\xa0\nEasy bruising\nProlonged epistaxis\xa0\nMenorrhagia\xa0\nOral bleeding (eg after tooth extraction)\xa0\n\nInvestigation\xa0\n\nVWF antigen level\n\nAt least 2 occasions\xa0\nWill be low or normal in Von Willebrand’s disease\xa0\nNote it is elevated by exercise and hyperthyroidism\nIt is decreased by hypothyroidism\xa0\n\n\nVon Willebrand factor ristocetin cofactor activity\nPT, platelet count and fibrinogen levels are usually normal\naPPT\xa0usually\xa0prolonged\n\nTreatment\xa0\n\nDesmopressin\xa0(DDAVP)\xa0\n\n\t\nIncreases factor VIII and VWF\xa0\nUseful in type 1, variably useful in type 2, not useful in type 3\n\n\nTranexamic acid\xa0\n\nAn antifibrinolytic agent\xa0\nUseful in management of epistaxis and menorrhagia\xa0\nAvoid in patients with history of thromboembolic disease or current upper urinary tract bleeding\n\n\nVWF/factor VIII concentrate', 'role': 'assistant'}]