A3型题患者女性，50岁。间歇性牙龈出血1年。体检：双下肢可见散在的出血点及紫癜，肝、脾不大。血红蛋白120g／L，红细胞40×10<img border="0" alt="" src="http://img.weimei168.com/uploads/upimg/20221202/11545033_0.gif">／L，白细胞5．5×10<img border="0" alt="" src="http://img.weimei168.com/uploads/upimg/20221202/11545033_0_1.gif">／L，分类正常，血小板15×10<img border="0" alt="" src="http://img.weimei168.com/uploads/upimg/20221202/11545033_0_2.gif">／L。为确诊首先应进行