Interstitial Lung Disease in Patients with Mixed Connective Tissue Disease: A Retrospective Study

Xueyan Shan,1,2 Yongpeng Ge3 1Department of Rheumatology, Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China; 2Postgraduate School, Beijing University of Chinese Medicine, Beijing, People’s Republic of China; 3Department of Rheumatology, The Key Laboratory of Myositis, China-Japan Friendship Hospital, Beijing, People’s Republic of ChinaCorrespondence: Yongpeng Ge, Department of Rheumatology, The Key Laboratory of Myositis, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, People’s Republic of China, Email gyp2016@163.comObjective: To investigate the clinical features, severity and prognosis of interstitial lung disease (ILD) in patients with mixed connective tissue disease (MCTD).Methods: We performed a retrospective study on clinical data of MCTD patients admitted to China-Japan Friendship Hospital between October 2012 and October 2022. Data including long-term follow-up were retrieved from medical records. We compared MCTD patients with and without ILD in terms of clinical features, laboratory and imaging findings, severity and treatment response.Results: A total of 59 patients were included, with a mean age of 46 years, among which 91.5% (n = 54) were females. Symptoms of pulmonary involvement were present in 44 patients (74.6%, 95% CI: 62.3– 84.9%). Based on lung high-resolution computed tomography (HRCT), ILD was diagnosed in 39 (66.1%) patients, among which 31 (79.5%) showed nonspecific interstitial pneumonia (NSIP) as the radiological pattern, 21 (53.9%) showed a reticulation pattern, while 24 (61.5%) showed ground glass opacity (GGO). Eight (13.6%) patients had pulmonary arterial hypertension (PAH), and 7 (11.9%) had pleural effusions. Based on pulmonary function tests (PFTs), 27 patients were divided into the mild 13 (48.1%) and moderate 14 (51.9%) groups. Multivariate analysis showed that gastroesophageal reflux (GER; OR=5.28, p=0.010) and cough (OR=4.61, p=