Patient characteristics
| Study cohort 1 (off PPI)# | Study cohort 2 (on PPI)¶ | |||
| BOS 0 | BOS 0p | BOS ≥1 | BOS 0+ BOS 0p§ BOS ≥1ƒ | |
| Subjects | 25 | 9 | 11 | |
| Male/female | 19/6 | 3/6 | 7/4 | 10/8 |
| Age yrs | 51±11 | 53±11 | 46±13 | 53±13 |
| CF/other## | 4/21 | 2/7 | 1/10 | 2/16 |
| SSLTx/SLTx/HLTx | 19/5/1 | 3/5/1 | 8/1/2 | 11/6/1 |
| Weeks after LTx | 114±69 | 130±54 | 227±124 | 112±60 |
| Patients with a history of AR ≥2 episodes | 4 | 2 | 5 | 4 |
| Patients colonised at study day | 4 | 1 | 3 | 4 |
| CMV donor/receptor 1/2/3¶¶ | 7/9/9 | 5/2/2 | 4/3/4 | 13/2/3 |
Data are presented as n or mean±sd. PPI: proton pump inhibitor; BOS: bronchiolitis obliterans syndrome; BOS 0: no BOS; BOS 0p: probable BOS; BOS≥1: BOS grade 1 or higher; CF: cystic fibrosis; SSLTx: double lung transplantation; SLTx: single lung transplantation; HLTx: heart–lung transplantation; AR: acute rejection; CMV: cytomegalovirus. #: n = 45; ¶: n = 18; +: n = 10; §: n = 2; ƒ: n = 6; ##: other diagnoses in study cohort 1 include chronic obstructive pulmonary disease (COPD; n = 15), CF (n = 7), pulmonary fibrosis (n = 6), primary pulmonary hypertension (n = 5), bronchiectasis (n = 3), lymphangioleiomyomatosis (LAM; n = 1), sarcoidosis (n = 1), pulmonary fibrosis due to congenital dyskeratosis (n = 1), hypersensitivity pneumonitis (n = 2), α1-antitrypsin deficiency emphysema (n = 2) and Williams–Campbell syndrome (n = 1). Other diagnoses in study cohort 2 include COPD (n = 8), CF (n = 2), pulmonary fibrosis (n = 3), primary pulmonary hypertension (n = 1), bronchiectasis (n = 1), LAM (n = 1), obliterative bronchiolitis (induced by a viral infection during childhood; n = 1) and histiocytosis X (n = 1). ¶¶: CMV status of the LTx donor (D) and receptor (R) are as follows: 1) D+/R+ or D-/R+, 2) D-/R-, and 3) D+/R-.