Viral infection does not affect lung disease

A study performed by researchers from the U.S., Korea and Japan has found that acute viral infection is not a primary reason of acute exacerbation of idiopathic pulmonary fibrosis (IPF), a progressive, deadly disease resultant in thickening and scarring of the lungs. Previous studies had recommended viral infection might cause exacerbation of IPF in a majority of patients who have the condition, which occurs most often in people between 50 and 70 years of age. "The etiology of acute exacerbation of IPF remainder unknown, and occult viral infection has been projected as one possible cause," said Harold Collard, MD, director of the Interstitial Lung Disease Program at the University of California, San Francisco.

"The results of this study recommend that the majority of cases of acute exacerbation of IPF are not due to viral infection." IPF is thought to result from an irregular fibroproliferative response in the lung. As lung tissue becomes stiff and thick, lung function and breathing are spoil. In some patients, these changes happen gradually over time, while in others the condition may cause acute periods of severe worsening. In this study, the researchers enrolled 43 patients with sharp exacerbation of IPF from two medical centers between 2006 and 2009. In addition, 69 patients with either constant IPF or acute lung injury (ALI) were enrolled from a single medical center as control subjects.

In all cases, bronchoscopy was complete as part of patients' clinical evaluations. Lung fluid and blood samples were together and analyzed using three separate, highly sensitive viral DNA detection techniques to test for the attendance of both known and unknown viruses. Results of these tests exposed evidence of viral infection in 33 per cent of the patients with exacerbation of idiopathic pulmonary fibrosis patients, only four of whom had proof of common respiratory viral infections. No viruses were sense in the lung fluid from stable patients.