NEJM看图识病（176）：家族性冷纤维蛋白原血症

Familial Primary Cryofibrinogenemia

A 50-year-old woman presented with a history of painful lesions involving cold-exposed areas of skin, a condition that had worsened every fall and disappeared every spring since childhood. The physical examination revealed ulcers, livedo, and bluish-purple discolorations with crusts and scar tissue on the ears (Panel A), hips, knees, fingers, and toes (Panel B). Many other members of the patient's family reported having similar symptoms. Laboratory evaluation showed a plasma cryofibrinogen level of 850 mg per liter. Cryofibrinogenemia is diagnosed when plasma that is clear at 37°C (Panel C) develops a precipitate when it is cooled to 4°C (Panel D). Unlike cryoglobulins, this cryoprecipitate does not form in serum. Symptoms result from vascular occlusion in cold-exposed areas. The condition is most often associated with an underlying inflammatory disorder, infection, or cancer, but familial primary cases with an autosomal dominant inheritance pattern have been described. In this patient, dextran, stanozolol, and nifedipine were administered, but cold avoidance was the only effective treatment.

50岁女患，儿童时期即开始出现反复发作的皮肤暴露部位的痛性皮损，皮损在秋冬季加重，春季好转消失。查体 示耳朵、臀部、膝部、手指，手趾  皮肤溃疡、青紫、色素沉着伴皮肤硬化、结痂。患者其它家庭成员有类似症状。患者诊断为 冷纤维蛋白原血症，即血浆在37摄氏度时澄清，冷却至4摄氏度时可见沉淀物。不同于冷球蛋白血症，冷纤维蛋白原沉淀不出现于血清。临床症状主要表现为暴露于寒冷空气中的皮肤血管阻塞，至皮肤软组织坏死。

此现象可多与其它潜存的异常炎症状态相关，以及感染或肿瘤。但如果家庭成员多人发病，与常染色体显性遗传相关。

在此患者，予输注右旋糖酐、康力龙，硝苯地平治疗，避免寒冷暴露是唯一有效的措施。

注意血清和血浆的区别

血液经抗凝处理后的全部血液为全血；离心除去血细胞后所得到的淡黄色液体为血浆。如血液不经抗凝处理，让其自行凝固，则在抽血后的一段时间内，血液会自动在一系列凝血因子的作用下发生凝集，血液首先凝固成一个整体，再经过一段时间或用离心机离心，血液中凝固的部分会与一些清澈淡黄色的液体分离开，这些液体称为血清。血清与血浆从表面上看似乎没有什么不同，但其内在的主要区别是血清中不含纤维蛋白原，是未经抗凝处理过的血液凝固后得到的。

抽血做化验中常遇到某些化验要求用血清测定、用全血测定、用血浆测定，即是指血液标本的三种主要处理方式和要求。

1)        血清多用于血液生化、免疫等方面的测定；

2)        血浆多用于凝血等方面的测定；

3)        全血则多用在血细胞、血常规、血沉等方面的测定。

血液的抗凝处理需要抗凝剂，选用什么抗凝剂应根据具体的实验要求进行选择。