Epstein-Barr virus DNA in bronchoalveolar lavage fluid from patients with idiopathic pulmonary fibrosis

Background: Idiopathic pulmonary fibrosis is the most common idiopathic interstitial pneumonia. The human herpesviruses and especially Epstein-Barr virus have been implicated in the etiology of idiopathic pulmonary fibrosis in a number of studies. Aim: The aim of this study was to investigate the potential association between idiopathic pulmonary fibrosis and Epstein-Barr virus. Methods: Bronchoalveolar lavage fluid and sera were collected from 63 patients out of whom 17 suffered of idiopathic pulmonary fibrosis and 46 of other interstitial lung diseases. Sera from 50 healthy, age-matched individuals were also collected. Antibodies to the early, nuclear, and capsid antigens of Epstein-Barr virus were determined by enzyme immunoassay and indirect immunofluorescence. Additionally polymerase chain reaction was performed in bronchoalveolar lavage fluid in order to investigate the presence of Epstein-Barr virus DNA. Positive polymerase chain reaction results were confirmed by nucleotide sequencing. Results: Statistically significant differences were observed in the frequency of IgA antibodies to viral capsid antigen among patients with idiopathic pulmonary fibrosis, patients with other interstitial lung diseases and healthy controls (60%, 24.4% and 22% respectively, p = 0.013). Epstein-Barr virus DNA was detected in the bronchoalveolar lavage fluid of 3 patients with idiopathic pulmonary fibrosis but in none of the patients with other diseases (p = 0,024). Conclusions: The results of this study support the association between IPF and EBV, at least in some cases, and provide evidence that BALF is an alternative for the detection of viral DNA in patients with IPF. However further investigation is required concerning the etiology of idiopathic pulmonary fibrosis.