This study will collect tissue specimens from healthy subjects and from patients with hereditary forms of pulmonary fibrosis (lung scarring) to learn about substances in the blood, urine, or lung that might change as a result of this disease. Cells and fluid from the blood, urine, and lung will be analyzed for measurements of genetic material and proteins.

Healthy volunteers, patients with Hermansky-Pudlak syndrome or familial pulmonary fibrosis, and relatives of patients with hereditary pulmonary fibrosis who are 18 years of age or older may be eligible for this study.

Participants are admitted to the hospital for 3 to 7 days for the following tests and procedures:

• Blood and urine tests, including blood tests for hepatitis B, hepatitis C, and HIV. No more than 250 milliliters (about 1 cup) of blood is drawn.
• Electrocardiogram (EKG) to examine heart function.
• Chest x-ray and computed tomography (CT) scan of the chest. CT scanning combines x-rays and computers to show the location, nature, and extent of diseases or abnormalities inside the body. It can be done from different angles to provide three-dimensional pictures of the part of the body being studied and allows the doctor to view body organs in small sections. The subject lies on a table in the scanner for the imaging test.
• Arterial blood gases. Blood is drawn from a small needle placed in an artery in the forearm while the subject is resting and immediately after exercising.
• Pulmonary function (breathing) tests. To measure lung function, the subject breathes deeply and holds the breath. A medication called albuterol may be given to dilate the airways.
• Exercise test. The subject rides a stationary bicycle or walks briskly on a treadmill while heart and lung function are measured. Arterial blood gases are measured at the end of the test.
• Fiberoptic bronchoscopy with lavage (washing) and bronchial brushing. Subjects undergo these tests to collect fluid and cells from the lungs.

Subjects undergo these tests to determine their level of lung inflammation. Before the procedures begin, the subject's mouth, nose and throat are numbed with an anesthetic. Drugs are given to reduce mouth secretions, coughing and wheezing. A pain reliever and sedative may also be given. A thin tube (bronchoscope) is passed through the nose or mouth into the bronchi (large breathing tubes) of the lungs. A salt-water solution is infused and then suctioned out. A small brush may be passed through the tube to brush an area of the airway wall to collect some cells. Then the bronchoscope is removed and the procedure is finished. Oxygen is administered and an EKG monitors heart function throughout the procedure. The procedure takes 20 to 40 minutes. Patients are observed overnight in the hospital. Patients with Hermansky-Pudlak syndrome may receive the drug desmopressin before the procedure to reduce the chance of bleeding.

• Lung biopsy. Healthy subjects do not undergo this surgical procedure. It may be done in some patients to establish a diagnosis. A small amount of lung tissue is removed for diagnostic and pathologic tests. Patients with Hermansky-Pudlak syndrome may receive desmopressin or a platelet transfusion, or both, before the procedure to reduce the chance of bleeding.
• Genetic evaluation. A blood sample is drawn to obtain DNA for testing to look for genes related to the development of pulmonary fibrosis or excessive scarring.