The purpose of this study is to: 1) to develop a method to quantify Epstein Barr Virus (EBV) load in lung tissue of humans and to determine whether EBV viral load is significantly higher in lung tissue from patients with idiopathic pulmonary fibrosis (IPF) than in control lung tissue; 2) to determine whether EBV localized to epithelial cells in IPF lungs and to relate epithelial positivity to tissue viral load; 3) to measure viral load in induced sputum from IPF subjects over time in order to determine whether periodic active herpes virus replication occurred in the respiratory tract; and 4) to compare longitudinal measures of viral load in induced sputum with simultaneously collected saliva in order to assess the clinical utility of the two approaches.

IPF is a progressive disease where there is no proven treatment, other than lung transplant. Doctors do not know what causes IPF. We think that IPF is caused by a viral infection, particularly herpes virus. The goal of this experiment is to build the case for a causal link between IPF and herpes virus. This information is important to help us develop new therapies to treat patients with IPF.

We will collect lung tissue at the time of lung transplant surgery from IPF patients and from organ donors as controls. Control lung tissue was collected if it was removed as a part of regular care or would otherwise be discarded. No extra tissue was taken solely for this research project.

We will also perform a prospective longitudinal study on IPF patients and their household partners. IPF subjects are included if they have no other pulmonary disease and the diagnosis of IPF is confirmed by lung biopsy or by clinical and chest CT findings. The control group will consist of subjects without respiratory symptoms or pulmonary diseases who are the household partner or spouse of an enrolled IPF subject and who accompanies the IPF patient to outpatient clinic visits. If there is no household partner, or if the partner is unwilling to participate, we will still enroll the IPF subject who qualifies for the study and is willing to participate. Saliva, induced sputum, and venous blood will be collected from IPF and control subjects after informed consent at each clinic visit. Visits usually are at approximately 3-4 month intervals over a one year period.

For the study on lung tissue, eligible subjects were IPF patients undergoing lung transplant surgery and from organ donors who died from non-pulmonary causes. For the study in clinic, subjects were IPF patients who had no other pulmonary disease other than IPF and the diagnosis of IPF was confirmed by lung biopsy or by clinical and chest CT findings. The control group consisted of subjects without respiratory symptoms or pulmonary diseases who were the household partner or spouse of an enrolled IPF subject and accompanied the IPF patient to outpatient clinic visits.

Exclusion Criteria:

• Failure of the patient to provide informed consent.

Patients with idiopathic pulmonary fibrosis (IPF) or controls with no underlying pulmonary disease