Department of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, No. 1 Shuai Fu Yuan, Dongcheng District, Beijing, 100730, China.
Peking University Institute of Haematology, Peking University People's Hospital, No. 11 Xizhimen South Street, Beijing, 100044, China.
BMC Pulm Med. 2021 Mar 16;21(1):88. doi: 10.1186/s12890-021-01451-4.
Patients with interstitial lung disease (ILD) are occasionally positive for anti-neutrophil cytoplasmic antibodies (ANCAs). Differences between ILDs secondary to microscopic polyangiitis (MPA) and isolated ANCA-positive idiopathic interstitial pneumonia (IIP) remain unclear. The aim of this study was to explore the differences in clinical features and outcomes between MPA-associated ILDs and isolated ANCA-positive IIPs.
We reviewed 1338 ILDs patients with available ANCA results and retrospectively analysed 80 patients who were ANCA-positive. MPA-associated ILDs (MPA-ILDs group) and isolated ANCA-positive IIPs (ANCA-IIPs group) were compared.
Among 80 patients with ANCA-positive ILDs, 31 (38.75%) had MPA-ILDs, and 49 (61.25%) had isolated ANCA-positive IIPs. Compared with ANCA-IIPs group, patients in MPA-ILDs group had a higher proportion of fever (p = 0.006) and higher neutrophil count (p = 0.011), erythrocyte sedimentation rate (ESR) (p < 0.001) and C-reactive protein (CRP) (p = 0.005). Multivariable analysis showed that ESR level was an independent risk factor for mortality in all 80 ANCA-positive ILDs patients (HR 1.028, p = 0.001). Survival in MPA-ILDs group was lower than that in ANCA-IIPs group, and further stratified analysis revealed that ANCA-IIPs patients with elevated ESR or CRP had a worse prognosis than those with normal inflammation markers, with 5-year cumulative survival rates of 60.00%, 86.90% and 100.00% in MPA-ILDs and ANCA-IIPs with and without elevated inflammation markers, respectively.
Among patients with ANCA-positive ILDs, the prognoses of ANCA-IIPs with normal inflammation markers, ANCA-IIPs with elevated inflammation markers and MPA-ILDs were sequentially poorer. Therefore, stratified treatment should be considered in the management of ILDs patients positive for ANCAs.
间质性肺疾病（ILD）患者偶尔会出现抗中性粒细胞胞浆抗体（ANCAs）阳性。显微镜下多血管炎（MPA）继发的ILD 与单纯 ANCAs 阳性特发性间质性肺炎（IIP）之间的差异仍不清楚。本研究旨在探讨 MPA 相关 ILD 和单纯 ANCAs 阳性特发性间质性肺炎之间的临床特征和结局差异。
我们回顾性分析了 1338 例可检测到 ANCAs 结果的 ILD 患者，其中 80 例 ANCAs 阳性。比较抗中性粒细胞胞浆抗体阳性的显微镜下多血管炎相关间质性肺疾病（MPA-ILDs 组）和单纯 ANCAs 阳性特发性间质性肺炎（ANCA-IIPs 组）。
在 80 例 ANCAs 阳性的 ILD 患者中，31 例（38.75%）为 MPA-ILDs，49 例（61.25%）为单纯 ANCAs 阳性特发性间质性肺炎。与 ANCA-IIPs 组相比，MPA-ILDs 组发热（p=0.006）、中性粒细胞计数（p=0.011）、红细胞沉降率（ESR）（p<0.001）和 C 反应蛋白（CRP）（p=0.005）更高。多变量分析显示，ESR 水平是所有 80 例 ANCAs 阳性 ILD 患者死亡的独立危险因素（HR 1.028，p=0.001）。MPA-ILDs 组的生存率低于 ANCA-IIPs 组，进一步分层分析显示，ESR 或 CRP 升高的 ANCA-IIPs 患者预后比炎症标志物正常的患者差，5 年累积生存率分别为 MPA-ILDs 组 60.00%、ANCA-IIPs 组炎症标志物正常 86.90%、炎症标志物升高 100.00%。
在 ANCAs 阳性的 ILD 患者中，炎症标志物正常的 ANCAs 阳性特发性间质性肺炎、炎症标志物升高的 ANCAs 阳性特发性间质性肺炎和 MPA-ILD 的预后依次更差。因此，在 ANCAs 阳性的 ILD 患者管理中应考虑分层治疗。
