Lung permeability in adult obliterative bronchiolitis

Airway and alveolar permeability and surface liquid thickness: theory

The thickness of airway surface liquid (ASL) can be calculated as the ratio of the permeability coefficient of an absorbed inert tracer to the percentage rate in which it decreases in content in the airway lumen. The percentage clearance of radiolabeled diethylenetriaminepentaacetic acid (DTPA) from human airways or lungs has been measured many times, with a mean value of 1.04 +/- 0.25 (SD) %/min. Rates of clearance from animal lungs of most species give values of the same order, although they are lower in the sheep and higher in the dog. Permeability coefficients have not been measured simultaneously with percentage clearances and not at all for human tissues. Values for mannitol and sucrose, of which the former gives a permeability coefficient approximately 25% greater than that for sucrose and DTPA in airway tubes and isolated mucosal sheets from experimental animals, give a mean approximately 7.1 x 10(-7) cm/s. This corresponds to thickness of ASl of approximately 20-150 microns for various species. The assumptions underlying this estimate are discussed. It is concluded that ASL thickness in vivo may be considerably greater than in vitro measurements involving rapid freezing of the airway wall. Estimates of alveolar permeability suggest that either it is very considerably lower than that of the airway epithelium, that methods to measure alveolar permeability mainly reflect airway permeability, or both.

Lung injury related to consuming Sauropus androgynus vegetable

BACKGROUND

Taking Sauropus androgynus, a Malaysian food, to reduce weight began as a fad in Taiwan in 1994. Some advocates of this fad developed pulmonary dysfunction. The aim of this study is to report the lung injury in patients taking Sauropus androgynus.

METHODS

From July 1995 to November 1995, we investigated 104 nonsmoking patients (one male and 103 females) with chest roentgenography, pulmonary function, test, and Technetium 99m-labeled diethylene triamine penta-acetate (Tc-99m DTPA) radioaerosol inhalation lung scintigraphy.

RESULTS

Among the 90 patients receiving Tc-99m DTPA inhalation lung scan, 46 (51.1%) patients had increased clearance of Tc-99m DTPA from lung and 20 (22.2%) patients had inhomogeneous deposition of the submicronic radioaerosol. Eighteen (18/100) patients had obstructive ventilatory impairment in pulmonary function test. Analyzing the results, we found that the patients with respiratory symptoms (n = 42) took more vegetables (p = 0.016), had increased clearance of Tc-99m DTPA (p = 0.010) and had lower FEV1 (p = 0.001), FEV1/FVC (p < 0.001), FEF25-75 (p = 0.001), VC (p = 0.002) and DLCO (p = 0.009) than the patients without respiratory symptoms (n = 62). FEV1 and FEV1/FVC were significantly reduced in patients with severe impairment of alveolar permeability. The cumulative dosage and duration of exposure were significantly associated with the reduction of FEV1 and FEV1/FVC.

CONCLUSION

The lung injury after taking Sauropus androgynus involves alveoli and/or small airways and is manifest as obstructive ventilatory impairment with inhomogeneous aerosol distribution and increased lung epithelial permeability.

Bronchoalveolar lavage and 99mTc-DTPA clearance as prognostic factors in asbestos workers with and without asbestosis

The aims of this study are to investigate the change-over time of lung function and chest radiographic findings in patients with asbestosis (AS) and asbestos workers without asbestosis (AW). Secondly, to correlate these changes with broncho-alveolar lavage (BAL) profiles and with lung epithelial permeability, as detected by half-time lung-to-blood (t1/2 LB) clearance of an inhaled aerosol of diethylene triamine pentacetate labelled with technetium 99 (99mTc-DTPA) obtained a mean period of 4.2 yr (range 2.3-5.8) previously. Thirty-three patients with asbestosis and 24 asbestos workers with substantial asbestos exposure were followed-up. Nineteen healthy smokers (HS) with no asbestos exposure who were followed up for a mean period of 3.9 yr were taken as a control group for spirometric changes. Compared with AW, FEV1, FVC and TLCO were lower in AS (P < 0.0001 in each case). Smoker AS and AW had lower numbers (P < 0.03) and percentages (P < 0.004) of BAL lymphocytes and higher numbers (P < 0.04) and percentages (P < 0.02) of BAL neutrophils plus eosinophils than ex- and non-smokers. Annual declines of FEV1 (dFEV1 yr-1) and FVC (dFVC yr-1) in AS and AW were significantly greater than in HS and predicted annual declines (P < 0.002 in each case). Annual declines of TLCO (dTLCO yr-1) and KCO (dKCO yr-1) in AS and AW were significantly greater than predicted annual declines (P < 0.002 in each case). No significant differences were noted between AS and AW in annual declines in any lung function measurement. dTLCO yr-1, dKCO yr-1 were significantly greater in smokers than in ex- and non-smokers, (P < 0.05 and P < 0.04 respectively). Annual decline did not relate to base line values for any lung function measurement. Numbers and proportions of BAL lymphocyte were higher (P < 0.008 and P < 0.02, respectively) and numbers and proportions of BAL neutrophils and eosinophils were lower (P < 0.02 and P < 0.03, respectively) in patients in whom dTLCO yr-1 was less than 0.3 mmol min-1 kPa-1 than in patients in whom dTLCO yr-1 was more than 0.3 mmol min-1 kPa-1. dTLCO yr-1 inversely correlated with t1/2 LB; r = 0.51; (P < 0.008). Patients in whom the radiograph remained unchanged had higher numbers (P < 0.002) and percentages (P < 0.001) of BAL lymphocytes than patients in whom the radiograph deteriorated.(ABSTRACT TRUNCATED AT 250 WORDS)