Viral infections in patients with an acute exacerbation of idiopathic interstitial pneumonia

Abstract

Background: Patients with slowly progressive idiopathic interstitial pneumonia, including idiopathic pulmonary fibrosis, often deteriorate, thus suggesting that the clinical course may be unpredictable. Such episodes are termed acute exacerbation of idiopathic interstitial pneumonia. The etiology of an acute exacerbation of idiopathic interstitial pneumonia is unknown. In this study, we tested the hypothesis that an acute exacerbation of idiopathic interstitial pneumonia is induced by respiratory viral infections.

Methods: Bronchoalveolar lavage fluid obtained from patients with an acute exacerbation of idiopathic interstitial pneumonia was tested for viral nucleic acid using polymerase chain reaction.

Results: Only 1 of the 14 patients with an acute exacerbation of idiopathic interstitial pneumonia exhibited evidence of respiratory syncytial virus B, and 2 patients exhibited evidence of cytomegalovirus. Seven patients fulfilled the diagnostic criteria of idiopathic pulmonary fibrosis.

Conclusions: Most cases with an acute exacerbation of idiopathic interstitial pneumonia are not caused by a viral infection.

Keywords: Acute exacerbation; BAL; BALF; CMV; DNA; IIP; IL; IPF; Idiopathic interstitial pneumonia; Idiopathic pulmonary fibrosis; PCR; RNA; RT; Sd; Viral infection; bronchoalveolar lavage; bronchoalveolar lavage fluid; cytomegalovirus; deoxyribonucleic acid; idiopathic interstitial pneumonia; interleukin; interstitial pulmonary fibrosis; polymerase chain reaction; reverse transcriptase; ribonucleic acid; standard deviation.