Pulmonary epithelial permeability in bronchiectasis

We measured pulmonary epithelial premeability in 17 non-smoking patients with generalized bronchiectasis, of whom six had cystic fibrosis, by determining the half-time clearance from lung to blood ($\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext><mtext>LB</mtext>}}$) of inhaled ^99mTc-labelled diethylene triamine pentaacetate. Their age range was 15–79 years and the range of their FEV₁ measurements was 20–87% of the predicted normal Sputum obtained by prestudy chest physiotherapy revealed significant colonies of Psuedomonas aeruginosa in six, Haemophilus influenzae in three, Staphylococcus aureus in three and Pasteurella mitocida in one patient, while in the remainder there was normal floral only. Lung clearance was significantly faster in the 13 culture-positive patients (mean $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext><mtext>LB</mtext>}}\text{=28}$ minutes) compared with the four culutre-negative patients (mean $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext><mtext>LB</mtext>}}\text{=54}$ minutes). There was no correlation between $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext><mtext>LB</mtext>}}$ and prestudy FEV₁. The study was repeated in six patients following a course of antibiotics. In two patients only was the sputum cleared of organisms and in those the lung permeability decreased significantly. There was no change in lung permeability in the four patients in whom it was impossible to eradicate the sputum organisms. Thus, in our patients with generalized bronchiectasis, lung permeability was increased only in those with both purulent sputum and significant colonization of the respiratory tract by bacterial pathogens. However, this increase in lung permeability was not associated with worse lung function.