Clinical Features and Outcome of Acute Exacerbation of Interstitial Pneumonia: Collagen Vascular Diseases-Related versus Idiopathic

Background: Relatively little is known about acute exacerbation (AE) of interstitial pneumonia associated with collagen vascular diseases (CVD-IPs). Objectives: This study was aimed at clarifying clinical characteristics and outcome in AE of CVD-IPs, compared with those of idiopathic interstitial pneumonias (IIPs). Methods: We retrospectively reviewed 112 admission cases with suspected AE of CVD-IPs or IIPs during 2003-2009. IIPs were diagnosed with idiopathic pulmonary fibrosis (IPF) or non-IPF, mostly based on radiologic findings. Of these, 15 AEs of CVD-IPs (6 rheumatoid arthritis, 6 dermatomyositis and 3 systemic sclerosis) and 47 AEs of IIPs (13 IPF and 34 non-IPF) were included. Results: The clinical characteristics in AE of CVD-IPs were similar to those of IIPs, except for younger age (63.3 +/- 6.8 vs. 73.8 +/- 9.1 years; p = 0.0001) and higher PaO(2)/FiO(2) at the onset of AE (205 +/- 81.2 vs. 145 +/- 53.8 mm Hg; p = 0.002) in the former. Dermatomyositis-related interstitial pneumonia (IP) showed a relatively indolent onset and was often associated with worsening control of the underlying disease, whereas AE of other CVD-IPs resembled that of IIPs. 90-day mortality of 33% in AE of CVD-IPs was similar to that of IIPs (44%; p = 0.44) or non-IPF (34%; p = 0.94), but was significantly better than that of IPF (69%; p = 0.04). Conclusion: Clinical features and outcome in AE of CVD-IPs were similar, if not identical, to those of IIPs, having a significant impact on the clinical course. AE of advanced IPF with typical radiologic features seems to have higher mortality compared with other forms of IP. Copyright (C) 2011 S. Karger AG, Basel