Clinical features and outcome of acute exacerbation in connective tissue disease-associated interstitial lung disease: A single-center study from India

Background: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is associated with high mortality, but there is limited clinical data on AE of interstitial lung disease (ILD) in connective tissue disease-associated ILD (CTD ILD). The present study was conducted to provide prevalence and clinical features of AE, as well as various risk factors associated with mortality among AE CTD ILD patients. Methods: Between May 2013 and April 2018, 15 patients who developed AE among 105 consecutive patients with CTD with chronic ILD were included. AE was defined using the criteria recently proposed by the IPF net, with slight modification for adaptation to CVD-IP6 (collagen vascular disease-associated interstitial pneumonia), and patients having CTD with AE met all the criteria. Results: Fifteen patients with mean age of 45.8 ± 13.9 years developed AE; the most common subgroup (n = 5, 33%) was systemic sclerosis. The mean duration (months) between diagnosis of ILD and AE was 56.5 ± 38.0 with mean follow-up duration of 24 ± 18.1 months. The baseline arterial oxygen pressure (PaO₂) was 81.7 ± 8.1 mm Hg and mean forced vital capacity (%) was 57.9 ± 8.9. Five patients requiring mechanical ventilation died. Patients with shorter duration (months) of disease between onset of ILD to AE had higher mortality, 40.4 ± 45.1 vs 64.6 ± 33.6. Those who had significantly lower baseline PaO₂ (mean ± SD), 72.6 ± 3.4 vs 86.2 ± 5.3 mm Hg (P =.002) had higher mortality. Conclusions: In our study, the majority of patients with AE CTD ILD had systemic sclerosis. Patients with lower baseline PaO₂ and those requiring mechanical ventilation had higher mortality.