Clinical features and outcome of acute exacerbation of interstitial pneumonia associated with connective tissue disease.

Acute exacerbation (AE) of interstitial lung disease is reported to be developed in not only idiopathic pulmonary fibrosis but also connective tissue disease-associated interstitial pneumonia (CTD-IP). As the significance of AE of CTD-IP has not been so widely recognized, its clinical feature is not fully elucidated. In the present study, we investigated the incidence, clinical features and outcome of AE of CTD-IP. We retrospectively reviewed admitted cases in our department with medical record from 2011 to 2015. Among 155 patients with CTD-IP, 10 (6.5%) cases developed AE (6 rheumatoid arthritis, 2 polymyositis/dermatomyositis, 1 systemic lupus erythematosus, 1 Sjögren syndrome), and one died of AE within 30 days. Median survival time after the onset of AE was 169 days in all 10 patients. The treatment with immunosuppressant just before AE onset might improve the prognosis of AE. The median survival time after the onset of AE was significantly longer in patients showing good response to corticosteroid compared with those with poor response to corticosteroid (805 days and 45 days, respectively) (p<0.05), suggesting that there are some cases in CTD-IP, showing the good response to corticosteroid even when AE was complicated.