Participants will have a medical history and physical examination, plus standard tests for diagnosing and treating their specific disorder. Tests may include routine blood and urine studies, X-rays or other imaging studies, allergy skin tests and lung function tests. Blood samples may be collected for research on immune system cells and other substances involved in immune function. Generally, about 2 to 6 tablespoons will be drawn at a time, but no more than 16 ounces will be collected over a 6-week period.