• INCLUSION CRITERIA:

To be eligible for this protocol, participants must:

• Have a molecular diagnosis of HPS-1 or HPS-4
• Be 18-70 years of age
• Have the expectation to live more than 3 months, i.e., an FVC greater than or equal to 30% of predicted

• Have evidence of severe pulmonary fibrosis, i.e.:

  1. A FVC less than or equal to 45% of predicted
  2. Reduced exercise tolerance lasting longer than 1 week on the Dyspnea Perception Scale
  3. No evidence of improvement in pulmonary fibrosis within the past year, as defined by an FVC increase of 10% or a DLco increase of 15%.
• Be available, willing, and able to come to the NIH Clinical Center for admission every 3 months.

EXCLUSION CRITERIA:

• An explanation for interstitial lung disease other than HPS, including but not limited to radiation, sarcoidosis, hypersensitivity pneumonitis, bronchiolitis obliterans organizing pneumonia, cancer
• Pregnancy or lactation
• History of ethanol abuse or recreational drug use in the past two years
• History of human immunodeficiency virus (HIV) or chronic viral hepatitits infection
• Chronic use of high-dose steroids (greater than 10 mg prednisone/day) intended for ongoing treatment of their interstitial lung disease
• Use of any of the following within 28 days of enrollment: investigational therapy, cytotoxic/immunosuppressive agents other than corticosteroids, including but not limited to azathioprine, cyclosphosphamide, methotrexate, cyclosporine, colchicine, interferon gamma-1b, bosentan;
• Any severe medical complication including but not be limited to uncontrolled seizures, repeated transient ischemic attacks, severe ataxia, uncontrolled migraine headaches, diplopia, repeated episodes of syncope, an untreated psychiatric disorder, recent myocardial infarction (past 6 months), unstable angina, clinically relevant and untreated arrhythmias, uncontrolled hypotension or hypertension (systolic blood pressure less than 80 or greater than 180 mm Hg), myocarditis, severe congestive left sided heart failure, hepatomegaly not due to right heart failure, renal glomerular impairment (creatinine clearance less than 35 ml/min/1.73 m(2)), pancreatitis, toxic thyroiditis, life-threatening malignancy;
• Significant laboratory abnormalities, including but not limited to serum potassium less than 3.0 or greater than 5.4 mEq/L, SGPT greater than 100 U/L, CK greater than 700 U/L, hemoglobin less than 9.0 g/dL, platelets less than 70 k/mm(3), leukocyte count less than 2.0 k/microL;
• For women of child-bearing age, failure to have an effective method of birth control. Oral contraceptives will be considered inadequate without a second method due to risk of reduced efficacy of BCP while taking Zileuton.