Fidler Lee M, Kandel Sonja, Fisher Jolene H, Mittoo Shikha, Shapera Shane
University Health Network, Department of Medicine, Division of Respirology, Toronto, Ontario, Canada.
Sunnybrook Health Sciences Centre, Department of Medicine, Division of Respirology, Toronto, Ontario, Canada.
Sarcoidosis Vasc Diffuse Lung Dis. 2021;38(2):e2021015. doi: 10.36141/svdld.v38i2.10971. Epub 2021 Jun 28.
Interstitial lung disease (ILD) is an established manifestation of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Autoimmune serologic screening is recommended by international consensus guidelines during the evaluation of idiopathic ILD, but ANCA testing only on a case-by-case basis.
We aimed to evaluate the role of ANCA screening in patients with idiopathic ILD.
We performed a retrospective review of patients seen between September 2015 and April 2017 in the ILD clinic at Toronto General Hospital. Patients referred with confirmed or suspected connective tissue disease were excluded. Patient demographics, symptoms, chest imaging, and pulmonary function testing was collected. We performed descriptive statistics based on the presence of ANCAs and estimated operating characteristics for ANCA screening.
In total, 360 patients with idiopathic ILD were reviewed, 159 met study inclusion criteria and 4 (2.5%) tested positive for ANCAs. Two patients (1.2%) had elevated myeloperoxidase-ANCAs (MPO-ANCA) and 2 (1.2%) had elevated proteinase-3-ANCAs (PR3-ANCA). There were no significant associations between patient demographics and ANCAs. One patient (0.6%) with PR3-ANCAs was diagnosed with vasculitis following rheumatologic evaluation. Despite negative ANCA testing, 1 patient (0.6%) was diagnosed with vasculitis following rheumatologic evaluation. The sensitivity and specificity of ANCA screening for vasculitis in patients with ILD was calculated as 50% (95% CI, 1.3%-98.7%) and 98% (95%CI, 4.4-155.5) respectively. Negative and positive likelihood ratios were 0.5 (95%CI 0.1-2.0) and 26.2 (95%CI 4.4-155.5) respectively.
ANCA screening in patients with idiopathic ILD rarely yields positive results. These results support an individualized approach to ANCA testing as opposed to widespread screening.
间质性肺病（ILD）是抗中性粒细胞胞浆抗体（ANCA）相关血管炎的一种既定表现。国际共识指南建议在特发性ILD评估期间进行自身免疫血清学筛查，但ANCA检测仅逐例进行。
我们旨在评估ANCA筛查在特发性ILD患者中的作用。
我们对2015年9月至2017年4月在多伦多综合医院ILD诊所就诊的患者进行了回顾性研究。排除确诊或疑似结缔组织病的患者。收集患者的人口统计学资料、症状、胸部影像学和肺功能检查结果。我们根据ANCA的存在情况进行描述性统计，并估计ANCA筛查的操作特征。
总共对360例特发性ILD患者进行了评估，159例符合研究纳入标准，4例（2.5%）ANCA检测呈阳性。2例患者（1.2%）髓过氧化物酶-ANCA（MPO-ANCA）升高，2例（1.2%）蛋白酶-3-ANCA（PR3-ANCA）升高。患者人口统计学资料与ANCA之间无显著关联。1例PR3-ANCA阳性患者经风湿病学评估后被诊断为血管炎。尽管ANCA检测为阴性，但1例患者（0.6%）经风湿病学评估后被诊断为血管炎。ILD患者中ANCA筛查对血管炎的敏感性和特异性分别计算为50%（95%CI，1.3%-98.7%）和98%（95%CI，4.4-155.5）。阴性和阳性似然比分别为0.5（95%CI 0.1-2.0）和26.2（95%CI 4.4-155.5）。
特发性ILD患者的ANCA筛查很少产生阳性结果。这些结果支持采用个体化的ANCA检测方法，而不是广泛筛查。
