Li Xiao-Li, Xu Peng-Cheng, Chen Tong, Yan Tie-Kun, Jiang Jian-Qing, Jia Jun-Ya, Wei Li, Shang Wen-Ya, Hu Shui-Yi
Department of Nephrology Department of Hematology, Tianjin Medical University General Hospital, Tianjin, China.
Medicine (Baltimore). 2017 Dec;96(51):e9128. doi: 10.1097/MD.0000000000009128.
The relationship between antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) and ANCA-negative vasculitis has not been elucidated.
A 64-year-old female with edema and proteinuria was admitted. A kidney biopsy indicated focal proliferative nephritis with crescents in 25% of glomeruli. Serum ANCA was negative. Eighteen months later, systemic symptoms emerged and acute kidney injury occurred. Serum ANCA against myeloperoxidase (MPO) turned positive. Repeated kidney biopsy showed more severe lesion than last time. Immunoglobulin (Ig)G was purified from serum obtained before the first kidney biopsy. Weak ANCA which could not be detected in serum was found in IgG.
MPO-ANCA-associated AAV developed from ANCA-negative renal-limited AAV.
The patient was treated with glucocorticoid.
The serum creatinine decreased to 2.17 mg/dL a week later. MPO-ANCA turned negative when re-examined 3 weeks later. No relapse has been observed during follow-up for 6 months.
This is the first reported case about the spontaneous transformation from ANCA-negative renal-limited AAV to ANCA-positive systemic vasculitis. There might be a slow process of epitope spreading in the pathogenesis of disease. Physicians should try their best to detect the ANCA in the diagnose and treatment of ANCA-negative AAV.
抗中性粒细胞胞浆抗体（ANCA）相关性血管炎（AAV）与ANCA阴性血管炎之间的关系尚未阐明。
一名64岁女性因水肿和蛋白尿入院。肾活检显示局灶增生性肾炎，25%的肾小球有新月体形成。血清ANCA阴性。18个月后，出现全身症状并发生急性肾损伤。抗髓过氧化物酶（MPO）血清ANCA转为阳性。重复肾活检显示病变比上次更严重。从首次肾活检前获取的血清中纯化出免疫球蛋白（Ig）G。在IgG中发现了血清中无法检测到的弱阳性ANCA。
由ANCA阴性的肾脏局限性AAV发展为MPO-ANCA相关性AAV。
患者接受糖皮质激素治疗。
一周后血清肌酐降至2.17mg/dL。3周后复查时MPO-ANCA转阴。随访6个月期间未观察到复发。
这是首例关于从ANCA阴性的肾脏局限性AAV自发转变为ANCA阳性的系统性血管炎的报道病例。在疾病发病机制中可能存在一个缓慢的表位扩展过程。医生在诊断和治疗ANCA阴性AAV时应尽力检测ANCA。
