Lungs of individuals with cystic fibrosis (CF) are frequently colonized with a number of bacterial pathogens. One of the most common organisms is Pseudomonas aeruginosa. Previous studies have shown the presence of the type III-secretion pathway within P. aeruginosa, implicating these cytotoxins as virulence factors for this organism. To evaluate further the effect of these cytotoxins on lung cells, we would like to collect plasma and tissue from individuals with CF. Because larger quantities of plasma than can safely be obtained by simple phlebotomy will be required, apheresis procedures performed in the Clinical Center Apheresis Unit will be used. To obtain lung cells from patients with CF infected with P. aeruginosa, tissue from explanted lungs will be collected in collaboration with INOVA Fairfax Hospital. We intend to look for expression of the type- III proteins of P. aeruginosa by measuring the immune response against components of the type- III pathway and their presence in lung cells.

• INCLUSION CRITERIA:

Individuals with CF with an identified mutation in the cystic fibrosis transmembrance regulator (CFTR) (i.e., any of the known variants of the CFTR gene, such as the change in F508 allele) who are between the ages of 18 years to 65 years will be included in the apheresis portion of the study. Patients will have been or will be genotyped under another protocol. Patients must be colonized or have a history of colonization with P. aeruginosa. Patients may have cultured other organisms (e.g., Burkholderia cepacia).

All patients undergoing lung transplantation will be included in the study. Based on data from various CF registries, the mean age for patients receiving transplant is 26 years with a range from 5 to 59 years. Any patient age 9 and over with CF undergoing transplantation will be eligible for the explantation portion of the study.

EXCLUSION CRITERIA:

There are no exclusion criteria for subjects in the transplant portion of the study.

Patients with CF will be excluded from the apheresis portion of the study if they are less than 18 years, weigh less than 40kg, or demonstrate:

1. Cardiovascular instability;
2. Severe anemia (hematocrit less than 28 percent, hemoglobin less than10gm/ml);
3. Thrombocytopenia (Platelets less than 50,000);
4. Inadequate venous access in the upper extremities (No central venous catheters will be used);
5. Severe coagulation disorder;
6. Positive serology for hepatitis B, C, or HIV;
7. Pregnancy;
8. Pulmonary hypertension;
9. Respiratory exacerbation requiring intravenous antibiotics;
10. Any other condition which the physician or Apheresis Unit staff considers a contraindication to the procedure.

Individuals who are unable to provide adequate consent/assent will be excluded from the study.