Trivioli Giorgio, Gopaluni Seerapani, Urban Maria L, Gianfreda Davide, Cassia Matthias A, Vercelloni Paolo G, Calatroni Marta, Bettiol Alessandra, Esposito Pasquale, Murtas Corrado, Alberici Federico, Maritati Federica, Manenti Lucio, Palmisano Alessandra, Emmi Giacomo, Romagnani Paola, Moroni Gabriella, Gregorini Gina, Sinico Renato A, Jayne David R W, Vaglio Augusto
Department of Biomedical Experimental and Clinical Sciences "Mario Serio", University of Firenze, and Nephrology Unit, Meyer Children's Hospital, Firenze, Italy.
Department of Medicine, University of Cambridge, Cambridge, UK.
Clin Kidney J. 2020 Sep 6;14(1):332-340. doi: 10.1093/ckj/sfaa139. eCollection 2021 Jan.
Although rapidly progressive glomerulonephritis is the main renal phenotype of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), slow renal disease progression is sometimes observed. These forms have been rarely discussed; we analysed their prevalence, clinico-pathological characteristics and outcome.
We screened patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis followed at seven referral centres and selected those with estimated glomerular filtration rate (eGFR) reduction <50% over a 6-month period preceding diagnosis. Data regarding patient features and response to treatment were retrieved.
Of 856 patients, 41 (5%) had slowly progressive renal AAV. All had MPA and all but one was P-ANCA/myeloperoxidase (MPO) ANCA-positive. At diagnosis, the median age was 70 years [interquartile range (IQR) 64-78] and extra-renal manifestations were absent or subclinical (interstitial lung lesions in 10, 24%). The median (IQR) eGFR was 23 mL/min/1.73 m (15-35); six patients (15%) had started renal replacement therapy (RRT). All had proteinuria (median 1180 mg/24 h, IQR 670-2600) and micro-haematuria. Main histologic findings were extracapillary proliferation at chronic stages and glomerulosclerosis; following Berden's classification, 6/28 biopsies (21%) were 'focal', 1/28 (4%) 'crescentic', 9/28 (32%) 'mixed' and 12/28 (43%) 'sclerotic'. At last follow-up (median 32 months, IQR 12-52), 20/34 patients (59%) treated with immunosuppression had eGFR improvement >25% as compared with diagnosis, while 4/34 (12%) had started RRT.
AAV may present with slow renal disease progression; this subset is hallmarked by advanced age at diagnosis, positive MPO-ANCA, subclinical interstitial lung lesions and chronic damage at kidney biopsy. Partial renal recovery may occur following immunosuppression.
尽管快速进展性肾小球肾炎是抗中性粒细胞胞浆抗体（ANCA）相关血管炎（AAV）的主要肾脏表型，但有时也会观察到肾脏疾病进展缓慢的情况。这些类型很少被讨论；我们分析了它们的患病率、临床病理特征及预后。
我们在七个转诊中心筛查了显微镜下多血管炎（MPA）和肉芽肿性多血管炎患者，并选择了在诊断前6个月内估计肾小球滤过率（eGFR）降低<50%的患者。收集了患者特征及治疗反应的数据。
856例患者中，41例（5%）患有缓慢进展性肾脏AAV。所有患者均为MPA，除1例患者外均为P-ANCA/髓过氧化物酶（MPO）ANCA阳性。诊断时，中位年龄为70岁[四分位间距（IQR）64-78]，无肾外表现或为亚临床症状（10例有间质性肺病变，占24%）。中位（IQR）eGFR为23 mL/min/1.73 m²（15-35）；6例患者（15%）已开始肾脏替代治疗（RRT）。所有患者均有蛋白尿（中位值1180 mg/24 h，IQR 670-2600）和镜下血尿。主要组织学表现为慢性期的毛细血管外增生和肾小球硬化；按照伯登分类，28例活检中有6例（21%）为“局灶性”，1/28（4%）为“新月形”，9/28（32%）为“混合型”,12/28（43%）为“硬化型”。在最后一次随访时（中位时间32个月，IQR 12-52），34例接受免疫抑制治疗的患者中有20例（59%）与诊断时相比eGFR改善>25%，而4例（12%）已开始RRT。
AAV可能表现为肾脏疾病缓慢进展；这一亚组的特点是诊断时年龄较大、MPO-ANCA阳性、亚临床间质性肺病变以及肾活检显示慢性损伤。免疫抑制治疗后肾脏功能可能部分恢复。
