Clinical characteristics of connective tissue disease-related interstitial lung disease: an analysis of 186 cases

Abstract

Objective To analyze the clinical characteristics of connective tissue disease related interstitial lung disease (CTD-ILD). Methods The demographic data, clinical manifestations, blood gas analysis, lung function, chest high resolution CT (HRCT), histopathology of 186 patients with CTD-ILD admitted in Jinhua Central Hospital from January 2013 to December 2017 were retrospectively analyzed. Results In 186 patients with CTD-ILD,70 were males and 116 were females, with a mean age of 56.22±12.27. Among them, 61 cases were polymyositis/dermatomyositis (DM/PM)-ILD, 44 cases were rheumatoid arthritis (RA)-ILD, 26 cases were interstitial pneumonia with autoimmune features (IPAF), 16 cases were systemic sclerosis (SSc)-ILD, 14 cases were Sjogren syndrome (SS)-ILD, 11 cases were overlap syndrome (OS)-ILD, 7 cases were systemic lupus erythematosus (SLE)-ILD, 5 cases were undifferentiated connective tissue disease (UCTD)-ILD, and 2 cases were mixed connective tissue disease (MCTD)-ILD. The incidence of respiratory symptoms was higher than that of systemic symptoms, and the incidence of systemic symptoms was higher than that of skin symptoms. Cough was the most common symptom of respiratory system, and arthralgia was the most common symptom of systemic symptoms, accounting for 54.9% (101/186) and 48.9% (91/186) respectively. Blood gas analysis showed that hypoxemia accounted for 56.5% (83/147) and type Ⅰ respiratory failure accounted for 26.5% (39/147) . The proportion of restrictive ventilation dysfunction in pulmonary function tests was 70.9% (105/148) and the diffuse dysfunction was 81.1% (120/148) . The manifestations on HRCT were reticular linear shadow (44.1%), ground-glass opacity (54.3%), consolidation (23.1%), nodules shadow (20.9%) and cystic low density shadow (9.1%) . The histopathological diagnosis mainly was non-specific interstitial pneumonia (NSIP, 43.0%) and usual interstitial pneumonia (UIP,40.0%). Conclusion The arterial blood gas analysis, lung function and chest HRCT screening, and lung histopathological examination are important for early identification and diagnosis of CTD-ILD. Key words: Connective tissue diseases; Lung diseases, interstitial; Blood gas analysis