Pseudomonas aeruginosa, Cyanide Accumulation and Lung Function in Cystic Fibrosis and Non-Cystic Fibrosis Bronchiectasis Patients

¹ Dept of Life Sciences, Division of Biology, Faculty of Natural Sciences, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, United Kingdom
² Dept of Gene Therapy, Faculty of Medicine, Imperial College London, Emmanuel Kaye Building, Manresa Rd, London SW3 6LR
³ Host Defence Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK

^* To whom correspondence should be addressed. E-mail: h.d.williams{at}imperial.ac.uk.

	Abstract

Pseudomonas aeruginosa is the most important respiratory pathogen in patients with cystic fibrosis (CF) and non-CF bronchiectasis. It is able to synthesise hydrogen cyanide, a potent inhibitor of cellular respiration. We investigated whether cyanide is present in the sputum of CF and non-CF bronchiectasis patients infected with P. aeruginosa, and whether the detection of cyanide affected lung function.

Cyanide was measured in sputum using a cyanide ion selective electrode.

Cyanide was detected in sputum from 15/25 CF and non-CF bronchiectasis patients with current P. aeruginosa infection, whereas it was not detected in any of the 10 patients without this organism (p<0.01). Maximum levels were 130µM (mean±SE: 72±6.6 µM). Concurrent lung function data were available on all 21 P. aeruginosa-infected CF patients; the group with measurable sputum cyanide (n=11) was not different from those without (n=10) on the basis of age or gender. However, those with detectable cyanide had significantly poorer lung function than those without (FEV₁% predicted: 26.8±3.8% versus 46.0±6.7%, p<0.01; FVC% predicted: 44.4±4.9% versus 60.1±7.7, p<0.05).

Cyanide is detectable in sputum from CF and non-CF bronchiectasis patients infected with P. aeruginosa and is associated with impaired lung function