The objective of this study is to determine the presence of bacterial species, and the immunologic and molecular mechanisms of granuloma formation that might be involved in the pathogenesis of sarcoidosis. The investigators will collect peripheral blood and bronchoalveolar lavage fluid samples to isolate bacterial DNA and blood monocytes and lymphocytes. Specimens will be obtained from patients with sarcoidosis, with non-sarcoid lung disease, and healthy volunteers to directly compare the bacterial species present and the characteristics of cells thought to be involved in granuloma formation.

Inclusion Criteria:

• Clinical diagnosis of sarcoidosis (30 subjects) or
• Clinical diagnosis of non-sarcoid interstitial lung disease (10 subjects) or
• Age-matched controls (30 subjects)
• Ability to provide informed consent

Exclusion Criteria:

• Any disease condition (such as anemia, unstable cardiac disease, etc.) that in the opinion of the subject's primary physician would put the patient at risk of harm from having 60 cc of blood drawn or for undergoing bronchoscopy for this study.
• Patients who are undergoing bronchoscopy for presumed infection.
• Pregnant women, women who may be pregnant, and women who are breastfeeding.
• Patients who have undergone lung transplantation.
• Persons who are unable or unwilling to undergo bronchoscopy, including those unable to be accompanied by a designated driver to the procedure.
• Persons who have taken antibiotics in the 90 days prior to consent.
• Known HIV, HCV, alcohol, or other substance abuse history.

Potential subjects will be patients with sarcoidosis (involving any organ system), with non-sarcoid interstitial lung disease, and healthy controls.