Effect of Smoking on Pulmonary Vascular Permeability: A Positron Emission Tomography Study

Abstract

Positron emission tomography (PET) can be used to evaluate pulmonary vascular endothelial permeability by measuring the pulmonary transcapillary escape rate (PTCER) for radiolabeled transferrin. Because epithelial permeability, as evaluated by other techniques, is significantly affected by cigarette smoking, we used PET to compare the effects of smoking on extravascular lung density (EVD) and PTCER in seven normal chronic cigarette smokers within 30 min of smoking a cigarette and seven normal nonsmokers. We found no difference in PTCER and EVD between the two groups. We conclude that the interpretation of acute or chronic lung injury studies with PET should not be affected by cigarette smoking in the subject population.

Acute effects of cigarette smoke on inflammation and oxidative stress: a review

“…Endothelial permeability, as measured by radiolabelled urea, decreased after ACS 18 but no differences could be detected when measured by PET scanning using radiolabelled transferrin. 19 Oxidative stress…”

Pulmonary studies using positron emission tomography

“…With a PET study of vascular permeability, the assumption is made: 1) that the distribution of the plasma protein tracer ( 68 Ga-labelled transferrin) at time zero (the time of the intravenous injection) is exclusively intravascular; and 2) that the vascular volume does not change throughout the study. The St Louis group, who have used the 68 Ga-transferrin method extensively [33,34,[39][40][41][42][43], use the K 1 , k 2 analysis [37] rather than the simple slope index of DAUBER et al [44], deriving the pulmonary transcapillary escape rate (PTCER) as follows:…”

“…The clinical results obtained by the St Louis group are set out in table 4. Unlike the 99m Tc-diethylenetriamine penta-acetate (DTPA) aerosol measurement of epithelial membrane clearance, the intravenous 68 Ga-transferrin exchange through the endothelium is not abnormal in smokers [34]; this means that a history of smoking is not a confounding issue in the interpretation of PTCER values. The method seems to be specific, judging by the normal values in congestive heart failure in the presence of an increase in extravascular volume (VEV) [33].…”