每日一题_2023.08.11

A 3-year-old girl presented to the emergency department with a 1-day history of dark urine and jaundice after the development of an upper respiratory tract infection 1 week earlier. The physical examination was notable for pharyngeal erythema and exudates, conjunctival pallor, and scleral icterus. There was no hepatosplenomegaly, rash, or acrocyanosis. Laboratory studies showed a new anemia and findings consistent with hemolysis. A direct antiglobulin test was positive for C3d and weakly positive for IgG. A subsequent peripheral blood smear is shown. What is the most likely diagnosis?

患儿女，3岁，1周前出现上呼吸道感染，出现黑尿、黄疸1 d就诊于急诊科。值得注意的体格检查包括咽部红斑和渗出、结膜苍白和巩膜黄疸。患者无肝脾肿大、皮疹或肢端发绀。实验室检查显示新发贫血和符合溶血的表现。直接抗人球蛋白试验C3d阳性，IgG弱阳性。随后进行外周血涂片检查。最有可能的诊断是什么?

A. Cold agglutinin syndrome 冷凝凝集素综合征

B. G6PD Deficiency G6PD缺乏症

C. Hemolytic uremic syndrome 溶血性尿毒症综合征

D. Hereditary spherocytosis 遗传性球形红细胞增多症

E. Warm autoimmune hemolytic anemia 温性自身免疫性溶血性贫血

答案解析：

血涂片显示不同大小和形状的红细胞，包括网织红细胞和球形红细胞，以及红细胞凝集。冷凝集素滴度为1:1024。诊断为感染后冷凝集素综合征引起的自身免疫性溶血性贫血。肺炎支原体、eb病毒和其他常见呼吸道病毒的检测结果均为阴性。我们提供了支持性治疗，包括输血和避寒。3周随访时，患儿感觉良好，贫血减轻。

正确答案：A