| Characteristic | Control patients | CF patients |
| Subjects n | 24 | 31 |
| Age yrs | 8.9 (5.0–11.9) | 9.3 (4.8–16.6) |
| White blood cells ×103 cells·mL−1 | 262 (185–390) | 524 (287–2015)¶ |
| Neutrophils ×103 cells·mL−1 | 8.8 (3.8–36) | 230 (37–1401)¶ |
| Lymphocytes ×103 cells·mL−1 | 33 (11–86) | 24 (1–100) |
| Macrophages ×103 cells·mL−1 | 145 (93–270) | 239 (115–525) |
| Eosinophils ×103 cells·mL−1 | 0 (0–0) | 0 (0–0) |
| Epithelial cells ×103 cells·mL−1 | 0 (0–5.9) | 0 (0–0) |
| Urea mg·dL−1 | 0.35 (0.20–0.60) | 0.30 (0.30–0.50) |
| Albumin μg·mL−1 | 66 (34–168) | 49 (37–92) |
| Pseudomonas-positive BALF | 0/24 | 8/31 |
| Positive for other organisms# | 2/24 | 9/31 |
Data are presented as median (interquartile range) or n/N, unless otherwise stated. #: four CF patients were positive for Staphylococcus aureus, three for Alcaligenes xylosoxidans, two for Haemophilus influenzae (one of whom was also positive for S. aureus), and one for Mycobacterium avium; two control patients were positive for Streptococcus pneumoniae. ¶: α<0.05.