Gallant Tara L, Zheng Emily, Hobbs Alicia M, Becka Alexander J, Bertsch Ruth A
College of Medicine, California Northstate University College of Medicine, Elk Grove, USA.
Family Medicine, Kaiser Permanente, Sacramento, USA.
Cureus. 2023 Jul 24;15(7):e42410. doi: 10.7759/cureus.42410. eCollection 2023 Jul.
Thrombotic microangiopathy (TMA) is a range of diseases characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ injury. Complement-mediated TMA is a rare, life-threatening subtype of TMA that occurs due to the uncontrolled activation of the alternative complement pathway in the absence of normal regulation, often resulting from deficiencies of various regulatory proteins. Anti-glomerular basement membrane (anti-GBM) disease, previously known as Goodpasture syndrome, is a life-threatening form of vasculitis in which immunoglobulin G autoantibodies bind to the alpha-3 chain of type IV collagen in alveolar and glomerular basement membranes. We present the case of a patient with a history of antiphospholipid syndrome who was diagnosed with complement-mediated TMA during hospital admission for elevated anti-GBM antibody titers discovered during an outpatient evaluation for elevated creatinine levels. Upon admission, treatment was started for presumed anti-GBM disease, including high-dose intravenous methylprednisolone injections and multiple plasmapheresis sessions. However, renal biopsy results showed no evidence of anti-GBM disease, but rather evidence of TMA. Subsequent laboratory studies revealed decreased complement levels, suggestive of a diagnosis of complement-mediated TMA. The patient was started on rituximab and eculizumab infusions, and she was discharged in stable condition after a 15-day hospitalization with outpatient appointments scheduled for genetic testing and further infusions. This case illustrates the importance of recognizing the key clinical and diagnostic features of complement-mediated TMA to promptly initiate appropriate therapy.
血栓性微血管病（TMA）是一系列以血小板减少、微血管病性溶血性贫血和器官损伤为特征的疾病。补体介导的TMA是TMA的一种罕见的、危及生命的亚型，它是由于替代补体途径在缺乏正常调节的情况下不受控制地激活而发生的，通常是由各种调节蛋白的缺陷引起的。抗肾小球基底膜（anti-GBM）病，以前称为Goodpasture综合征，是一种危及生命的血管炎形式，其中免疫球蛋白G自身抗体与肺泡和肾小球基底膜中的IV型胶原α-3链结合。我们报告一例有抗磷脂综合征病史的患者，该患者在因门诊评估肌酐水平升高而发现抗GBM抗体滴度升高住院期间被诊断为补体介导的TMA。入院时，针对疑似抗GBM病开始治疗，包括大剂量静脉注射甲基泼尼松龙和多次血浆置换。然而，肾活检结果显示无抗GBM病证据，而是TMA证据。随后的实验室检查显示补体水平降低，提示诊断为补体介导的TMA。该患者开始接受利妥昔单抗和依库珠单抗输注，住院15天后病情稳定出院，并安排了门诊基因检测和进一步输注。本病例说明了认识补体介导的TMA的关键临床和诊断特征以迅速启动适当治疗的重要性。
