Objective: Acute exacerbation of diffuse parenchymal lung disease (DPLD) is a condition in which patients with usual interstitial pneumonia (UIP), and other forms of interstitial lung disease, develops rapid respiratory failure, accompanied by extensive radiological infiltrates, and had no evidence of infection. The pathologic features of this condition are usually diffuse alveolar damage (DAD) and the outcome is poor. Our study was to define the clinicopathologic features and outcome of acute exacerbation in 3 patients with UIP and 3 with nonspecific interstitial pneumonia (NSIP).
Method: The clinical data of the 6 patients from April 1999 to Jun 2007 were analyzed retrospectively.
Results: In the 6 patients, 2 were males. The median age was 51 yrs (29 -57 yrs). Three case had UIP [1 UIP/idiopathic pulmonary fibrosis (IPF), 1 UIP/dermatomyositis (DM), 1 UIP/UCTD], 2 had NSIP (1 idiopathic NSIP, 1 NSIP/DM), and 1 was diagnosed as DAD (the basic pathology was NSIP/DM) by autopsy. Four of the patients underwent video-assisted thoracoscopic surgery (VATS) for diagnosis, and 1 underwent CT-guided transthoracic needle biopsy. Two of them underwent surgical lung biopsy 1 week before acute exacerbation. Five cases had fever. Computed tomography data were available in all cases and showed the presence of extensive bilateral ground-glass opacities (5/6), sometimes accompanied by focal consolidation (2/6), superimposed on underlying fibrosis. The median oxygenation index was 200 (quartile range: 158-237) mm Hg (1 mm Hg = 0.133 kPa). Five patients were treated with corticosteroids, and in some combined with cyclophosphamide or intravenous immunoglobulin. Two patients survived the acute episode and were discharged from hospital. All 3 patients using mechanical ventilation died.
Conclusions: Both UIP and NSIP can develop acute exacerbations. The trigger of acute exacerbation was unclear, but in some cases it maybe related to VATS. The clinical features include rapid respiratory failure, accompanied by extensive radiological infiltrates. The fatality is high. Corticosteroids or intravenous immunoglobulin may be helpful in the treatment of the condition.