To the Editor:
Worldwide, about 40% of lung transplantations (LTx) are performed for end-stage emphysema [1]. Eligible patients are enrolled on the waiting list after at least 6 months of smoking cessation [1]. Although in most centres smoking behaviour after LTx is not routinely monitored, resuming smoking can complicate post-transplant outcome [2–5].
In general, smoking relapse can be found in 12–40% of all liver, heart and renal transplant patients [3]. Smoking is mostly assessed by use of a questionnaire. Only the study of Botha et al. [4] combined a questionnaire with urinary cotinine detection. We previously reported post-LTx smoking in 11% of our LTx patients [6]. Patients that restart smoking after heart [4] and liver transplantation [5] have an increased prevalence of cancer, yet there are no data for LTx.
We assessed all living, mainly adult (98%), LTx patients (n=331, of whom 230 were also included in our previous study [5]) with a minimal follow-up of 1 year after approval by the local Ethics Committee (approval number S51577) and informed consent. Smoking behaviour was investigated by a questionnaire, semi-quantitative and quantitative measurement of cotinine, and exhaled carbon monoxide levels. The questionnaire addressed past and current smoking habits. Second-hand smoking was defined as an living with a relative who smoked. The exhaled carbon monoxide level was quantified using an electrochemical sensor (Bedfont Scientific, Kent, UK) (detection limit 1 ppm) as previously described [5]. An exhaled carbon monoxide value ≥10 ppm was considered positive.
Quantitative cotinine analysis was …