Subject characteristics and results of quantification of activin-A, activin-A receptor type IIA (Act-RIIA), activin-like kinase (ALK)-4 and airway angiogenesis in all groups examined
| Healthy controls | Mild/moderate asthmatics | Severe asthmatics | |
| Subjects | 16 | 19 | 22 |
| Age years | 46.5 (38.7–56.7) | 43.0 (38–61) | 50.5 (39.4–59) |
| Male/female | 10/6 | 6/13 | 3/19 |
| Asthma duration years | NA | 30 (2–63) | 34 (12–63) |
| BMI kg·m-2 | 26.7 (24.4–28.8) | 27.3 (23.4–29.9) | 29.3 (25.0–31.6) |
| FEV1 % pred | 92.0 (85.3–103.1) | 82.2 (68.0–89.8)* | 67.2 (52.8–79.4)**, *** |
| Atopy | 0 | 11 | 17 |
| IgE IU·mL−1 | 33 (19.5–43.7) | 73 (31–168) | 120 (63–366)**, *** |
| LABA | 16 | 22 | |
| LTRA | 4 | ||
| ICS μg·day−1# | NA | 600±55 | 1800±89 |
| OCS mg·day−1¶ | NA | NA | 12 (9±1) |
| Activin-A levels pg·mL−1 | |||
| Serum | 103 (63–169) | 265 (110–367) | 206 (123–342) |
| BALF | 334 (102–391) | 517 (370–612) | 499 (343–569) |
| Airway epithelial cells % of total epithelial cells | |||
| Activin-A+ | 4 (2–19.2) | 55 (32–68) | 45.5 (25.7–68) |
| Act-RIIA+ | 64 (48–75) | 29 (10–38.5) | 18 (4–34) |
| ALK-4+ | 58.5 (43.2–75.5) | 51 (42–69.5) | 39 (21–49) |
| Airway subepithelial cells·mm−2 | |||
| Activin-A+ | 10 (4–27.1) | 140 (56–257) | 293 (182–555) |
| Act-RIIA+ | 240 (193–305) | 137 (18.5–175.5) | 44 (0–132) |
| ALK-4+ | 203 (139–333) | 120 (69–160) | 89 (12–170) |
| Angiogenesis vessels·mm−2 | 80.5 (59.7–99.7) | 158.0 (98–220) | 207.5 (151.3–300.5) |
Data are presented as n, median (interquartile range) or mean±sem, unless otherwise stated. BMI: body mass index; FEV1: forced expiratory volume in 1 s; LABA: long-acting β2 agonists; LTRA: leukotriene receptor antagonists; ICS: inhaled corticosteroids; OCS: oral corticosteroids; BALF: bronchoalveolar lavage fluid; NA: not applicable. #: beclometasone dipropionate chlorofluorocarbon equivalent dosage; ¶: prednisolone equivalent dosage. *: p<0.05 compared to healthy controls; **: p<0.01 compared to mild/moderate asthmatics; ***: p<0.001 compared to healthy controls.