患儿，女，10岁，因皮肤出血、血尿38 h，皮肤黄染、少尿6 h入院。入院体格检查：全身广泛皮下出血点，皮肤巩膜黄染。实验室检查示贫血，血小板减少，肾功能损伤及乳酸脱氢酶显著升高。初步诊断血栓性微血管病，非典型溶血尿毒综合征（atypical hemolytic uremic syndrome, aHUS）可能性大。入院9 h内（起病48 h内）即启动依库珠单抗治疗。首剂依库珠单抗输注后，患儿溶血迅速停止，且血小板、肾功能逐步恢复正常。全外显子测序检出CFHR1基因exon2及CFHR4基因exon1纯合缺失。aHUS起病急骤、进展迅猛，患儿出现血小板减少、微血管病溶血性贫血及急性肾损伤三联征时，应高度警惕aHUS；超早期（起病48 h内）应用依库珠单抗可快速阻断补体介导的血栓性微血管病进程，逆转器官损伤，改善远期预后。此外，补体相关基因检测对病因溯源及个体化依库珠单抗疗程制定具有重要意义。

A 10-year-old girl was admitted with a 38-hour history of widespread subcutaneous petechiae and hematuria and a 6-hour history of jaundice and oliguria. Physical examination revealed widespread subcutaneous petechiae and jaundice of the skin and sclera. Laboratory tests showed anemia, thrombocytopenia, acute kidney injury, and markedly elevated lactate dehydrogenase. Thrombotic microangiopathy was initially diagnosed, with a high suspicion of atypical hemolytic uremic syndrome (aHUS). Eculizumab was initiated within 9 hours of admission (within 48 hours of onset). After the first infusion, hemolysis rapidly ceased, and the platelet count and renal function gradually returned to normal. Whole-exome sequencing identified homozygous deletions of CFHR1 exon 2 and CFHR4 exon 1. aHUS typically has abrupt onset and rapid progression. Clinicians should maintain high suspicion for aHUS when the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury is present. Ultra-early eculizumab (within 48 hours of onset) rapidly blocks complement-mediated thrombotic microangiopathy, reverses organ injury, and improves long-term prognosis. Additionally, complement-related genetic testing is important for etiological clarification and individualized determination of eculizumab treatment duration.