Thajudeen B, Sussman A, Bracamonte E
Division of Nephrology, University of Arizona, Tucson, Ariz., USA.
Division of Pathology, University of Arizona, Tucson, Ariz., USA.
Case Rep Nephrol Urol. 2013 Dec 14;3(2):139-46. doi: 10.1159/000357520. eCollection 2013 Jul.
Atypical hemolytic uremic syndrome (aHUS) is a rare thrombotic microangiopathy (TMA) characterized by the triad of hemolytic anemia, thrombocytopenia, and acute renal failure. Eculizumab, a monoclonal complement C5 antibody which prevents the induction of the terminal complement cascade, has recently emerged as a therapeutic option for aHUS. We report a case of aHUS successfully treated with eculizumab. A 51-year-old male was admitted to the hospital following a mechanical fall. His past medical history was significant for rheumatic valve disease and mitral valve replacement; he was on warfarin for anticoagulation. A computed tomography scan of the head revealed a right-sided subdural hematoma due to coagulopathy resulting from a supratherapeutic international normalized ratio (INR). Following treatment with prothrombin complex concentrate to reverse the INR, urine output dropped and his serum creatinine subsequently increased to 247.52 μmol/l from the admission value of 70.72 μmol/l. Laboratory evaluation was remarkable for hemolytic anemia, thrombocytopenia, elevated lactate dehydrogenase (LDH), low haptoglobin, and low complement C3. A renal biopsy was consistent with TMA, favoring a diagnosis of aHUS. Treatment with eculizumab was initiated which resulted in the stabilization of his hemoglobin, platelets, and LDH. Hemodialysis was terminated after 2.5 months due to improvement in urine output and solute clearance. The interaction between thrombin and complement pathway might be responsible for the pathogenesis of aHUS in this case. Eculizumab is an effective therapeutic agent in the treatment of aHUS. Early targeting of the complement system may modify disease progression and thus treat aHUS more effectively.
非典型溶血性尿毒症综合征（aHUS）是一种罕见的血栓性微血管病（TMA），其特征为溶血性贫血、血小板减少和急性肾衰竭三联征。依库珠单抗是一种单克隆补体C5抗体，可阻止终末补体级联反应的诱导，最近已成为aHUS的一种治疗选择。我们报告一例用依库珠单抗成功治疗的aHUS病例。一名51岁男性因机械性跌倒入院。他既往有风湿性瓣膜病和二尖瓣置换病史；正在服用华法林进行抗凝治疗。头部计算机断层扫描显示，由于国际标准化比值（INR）超治疗范围导致凝血障碍，出现右侧硬膜下血肿。在用凝血酶原复合物浓缩物治疗以纠正INR后，尿量减少，血清肌酐随后从入院时的70.72μmol/l升至247.52μmol/l。实验室检查结果显示有溶血性贫血、血小板减少、乳酸脱氢酶（LDH）升高、触珠蛋白降低和补体C3降低。肾活检符合TMA，支持aHUS的诊断。开始用依库珠单抗治疗，结果其血红蛋白、血小板和LDH稳定。由于尿量和溶质清除率改善，2.5个月后停止血液透析。在该病例中，凝血酶与补体途径之间的相互作用可能是aHUS发病机制的原因。依库珠单抗是治疗aHUS的有效治疗药物。早期靶向补体系统可能改变疾病进程，从而更有效地治疗aHUS。
