[Clinical features and survival analysis of microscopic polyangiitis-associated interstitial lung disease:a retrospective study of 28 patients].

Objective: To explore the clinical features, laboratory examination and imaging features of microscopic polyangiitis (MPA)-associated interstitial lung disease (ILD), and to perform survival analysis. Methods: The records of 28 patients with MPA-ILD who were treated at the Affiliated Hospital of Medical School of Ningbo University were reviewed retrospectively from August 2014 to November 2021. The patients' clinical features, laboratory parameters, pulmonary function test, echocardiography, chest CT scan findings and therapeutic regimen were analyzed, and the relevant data were statistically analyzed. Results: There were 18 males and 10 females, with an average age of (70.1±9.3) years. Among them, 13 patients had a history of smoking. The main clinical manifestations were cough (14/28), fever (12/28), chest tightness, shortness of breath (12/28) and hemoptysis (3/28). Sixteen patients had renal involvement, and 78.57% (22/28) and 89.28% (25/28) of the patients had elevated C-reactive protein (CRP) and ESR respectively. Sixteen (16/28) patients had increased rheumatoid factor (RF), and the positive rate of myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) was 82.12% (23/28). 96.43% (27/28) of ILDs were diagnosed before or at the same time as MPA. The chest radiological pattern was mainly usual interstitial pneumonia (UIP) or UIP-like (15/28), followed by nonspecific interstitial pneumonia (NSIP) (8/28). Compared with non-UIP-like patients, UIP or UIP-like patients were older (P=0.018), and had higher serum LDH level (P=0.041), but serum creatinine level was significantly lower (P=0.041). Univariate and multivariate survival analysis showed that inappropriate treatment (HR=9.81, 95%CI: 1.68-57.29, P=0.011) and elevated serum LDH (HR=4.11, 95%CI: 0.99-17.00, P=0.051) were independent risk factors for shortened survival of MPA-ILD, while elevated RF (HR=0.22, 95%CI: 0.06-0.91, P=0.037) was a protective factor for prolonged survival. Conclusions: MPA-ILD patients had fewer systemic vasculitis symptoms. Most of the ILD patients were diagnosed before or at the same time as MPA. The chest radiological pattern was mainly UIP or UIP-like, followed by NSIP. Early use of glucocorticoids combined with immunosuppressant or rituximab could improve the survival rate of MPA-ILD. The elevated serum LDH was an independent risk factor for shortened survival of MPA-ILD, while elevated RF was a protective factor for prolonged survival.目的： 探讨显微镜下多血管炎相关间质性肺疾病（MPA-ILD）临床、实验室检查及影像学特征并进行生存分析。 方法： 回顾性分析2014年8月至2021年11月在宁波大学医学院附属医院确诊的28例MPA-ILD患者的临床资料，28例中男18例，女10例，年龄为（70.1±9.3）岁，总结本组患者的临床表现、实验室检查、肺功能、心脏彩超、胸部CT及治疗方案等，并对相关数据进行统计学分析。 结果： 本组患者中13例存在吸烟史，临床主要表现为咳嗽（14/28），发热（12/28），胸闷气促（12/28）及咯血（3/28），16例存在肾脏累及，多数患者存在C反应蛋白（22/28）和红细胞沉降率（25/28）升高，16例存在类风湿因子（RF）增高，23例髓过氧化物酶（MPO）-ANCA阳性。27例患者在MPA诊断之前发现ILD或与MPA同时诊断ILD，胸部CT模式主要为UIP型或UIP样（15/28），其次为NSIP型（8/28）。UIP型或UIP样患者较非UIP样患者年龄更大（P=0.018），血LDH更高（P=0.041），但血肌酐却明显较低（P=0.041）。通过单因素和多因素生存分析显示未正规治疗（HR=9.81，95%CI：1.68~57.29，P=0.011）及血LDH升高（HR=4.11，95%CI：0.99~17.00，P=0.051）是MPA-ILD生存期缩短的独立危险因素，而RF升高（HR=0.22，95%CI：0.06~0.91，P=0.037）是生存期延长的保护因素。 结论： MPA-ILD全身血管炎症状较少，绝大部分ILD在MPA诊断之前出现或与MPA同时诊断，影像表现主要为UIP型或UIP样，其次为NSIP型，尽早使用激素联合免疫抑制剂或激素联合利妥昔单抗能够提高MPA-ILD生存率，血LDH升高是MPA-ILD生存期缩短的独立危险因素，而RF升高则是生存期延长的保护因素。.