Induced sputum cell profiles in lung transplant recipients with or without chronic rejection: correlation with lung function

BACKGROUND Sputum induction is a non-invasive procedure for measuring inflammatory processes of the lower respiratory tract. The aim of this study was to establish sputum cell counts and differentials in patients after lung transplantation (LTx), with or without chronic transplant rejection. METHODS Sputum induction was performed in 41 LTx patients (25 single LTx (sLTx), 16 double LTx (dLTx) and 15 healthy non-smoking volunteers. Sputum was processed according to standard protocols. Total cell count was calculated as mean (SE) cells × 106/ml sputum and cell differential (%) was evaluated after staining. Cellular profiles were correlated with lung function. RESULTS Total sputum cell counts were increased in sLTx (9 (1.9) cells × 106/ml, p=0.01) and dLTx patients (7.2 (1.5) × 106/ml, p=0.01) compared with healthy controls (2.6 (0.6) × 106/ml). There was also a marked sputum neutrophilia in both patient groups (59 (6)% and 62 (6)%, respectively, p