Solute permeability of the alveolar capillary barrier.

Barrowcliffe, M. P.; Jones, J. G.

doi:10.1136/thx.42.1.1

Cited by 74 publications

(42 citation statements)

References 67 publications

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“…By contrast, in idiopathic pulmonary fibrosis (IPF), there is substantial evidence that epithelial cell dysfunction contributes to the fibrotic microenvironment [4,5], and markers of epithelial injury have been linked to outcome [1,[6][7][8]. Clearance of inhaled technetium-99m ( 99m Tc)-labelled diethylene triamine pentacetate (DTPA) from the lung, a measure of epithelial permeability/injury [9], is abnormal in several interstitial lung diseases, including SSc-ILD [1,10] and IPF [1,8,11].…”

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confidence: 99%

Increased epithelial permeability in pulmonary fibrosis in relation to disease progression

Goh¹,

Anagnostopoulos²,

Hansell³

et al. 2010

European Respiratory Journal

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Epithelial injury contributes to pathogenesis in idiopathic pulmonary fibrosis (IPF) but its role in the interstitial lung disease (ILD) of systemic sclerosis (SSc) is uncertain. We quantified the prognostic significance of inhaled technetium-99m ( 99m Tc)-labelled diethylene triamine pentacetate (DTPA) pulmonary clearance, a marker of the extent of epithelial injury, in both diseases. Baseline 99mTc-DTPA pulmonary clearance was evaluated retrospectively in patients with SSc-ILD (n5168) and IPF (n597) against mortality and disease progression.In SSc-ILD, the rapidity of total clearance (hazard ratio (HR) 1.02, 95% CI 1.01-1.03; p50.001) and the presence of abnormally rapid clearance (HR 2.10; 95% CI 1.25-3.53; p50.005) predicted a shorter time to forced vital capcity (FVC) decline, independent of disease severity. These associations were robust in both mild and severe disease. By contrast, in IPF, delayed clearance of the slow component, an expected consequence of honeycomb change, was an independent predictor of a shorter time to FVC decline (HR 1.01, 95% CI 1.00-1.02; p,0.01).Epithelial injury should be incorporated in pathogenetic models in SSc-ILD. By contrast, outcome is not linked to the overall extent of epithelial injury in IPF, apart from abnormalities ascribable to honeycombing, suggesting that core pathogenetic events may be more spatially focal in that disease.

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confidence: 99%

Increased epithelial permeability in pulmonary fibrosis in relation to disease progression

Goh¹,

Anagnostopoulos²,

Hansell³

et al. 2010

European Respiratory Journal

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“…The equivalent pore radii calculated from physiological studies are around 0.6 -1.0 nm for the epithelium and around 4.0 -5.8 nm or more for the endothelium (Taylor & Gaar 1970). As the epithelium is the most impermeable component of the alveolar-capillary barrier, injury to this membrane can enhance solute diffusion from the alveolar to the vascular compartment (Barrowcliffe & Jones 1987). Measurement of lung clearance of aerosolized 99m Tc-DTPA is currently used to assess the integrity of the alveolus-capillary barrier.…”

Section: Discussionmentioning

confidence: 99%

“…The procedure to assess the integrity of the pulmonary epithelium is based on the clearance rate of aerosolized 99m Tc-DTPA (Mason et al 1983). As the epithelium is the most impermeable component of the alveolar-capillary barrier, injury to this membrane can enhance solute diffusion from the alveolar to the vascular compartment (Barrowcliffe & Jones 1987). Mason et al (1987) have found in 12 patients with pneumocystis pneumonia very high values of 99m Tc-DTPA clearance rate.…”

Section: Introductionmentioning

confidence: 99%

Alveolus-capillary permeability on both normal and HIV seroreactive individuals

Carriel¹,

Maliska²,

Piloto

et al. 2007

Braz. arch. biol. technol.

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“…With time, an artifact due to accumulation of the indicator in tissues and blood may become prominent, resulting in apparent slowing of clearance. Some investigators correct for this accumulation of radioactivity in the pulmonary interstitium, blood, and chest wall (31). Controversy persists regarding the accuracy and need for such a correction (32,33).…”

Section: Discussionmentioning

confidence: 99%

Effect of Mechanical Ventilation and Barotrauma on Pulmonary Clearance of 99mTechnetium Diethylenetriamine Pentaacetate in Lambs

1990

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ABSTRACT. We studied the effect of positive pressure mechanical ventilation on the pulmonary clearance (k) of 99mtechnetium diethylenetriamine pentaacetate (99mTc-DTPA) in lambs. Twelve lambs were anesthetized and ventilated with air at 25 breathslmin and with end expiratory airway pressure at 2 cm H20 for a minimum period of 8 h. Four lambs received normal pressure ventilation with peak airway pressure at 17 f 3 cm Hz0 and eight received high pressure ventilation with peak airway pressure at 41 f 2 cm H20. Three 99mTc-DTPA clearance studies were done in each lamb; at the start and after 4 and 8 h of mechanical ventilation. All clearance measurements were made at normal peak airway pressure 16 f 3 cm H20. Baseline clearance rate, k, (n = 12) was 1.2 f 0.5% (SD). During normal pressure ventilation, k increased from 1.0 2 0.5 to 2.2 f 0.8% after 4 h and to 2.7 f 0.8% after 8 h. During high pressure ventilation, k increased from 1.4 f 0.4 to 3.6 f 1.3% after 4 h and to 4.8 f 1.2% after 8 h. To see if 8 h of mechanical ventilation was associated with other evidence of lung epithelial injury, we determined the movement of IlZ5 labeled albumin from the interstitium into the airspace, lung water content, lung histology, and lung lavage constituents in the lambs at the end of the study. All variables were similar between ventilated and four unventilated lambs, except the percentage of alveolar macrophages recovered by lavage, which was more in the ventilated lambs. We conclude that positive pressure mechanical ventilation results in a continuous increase in the pulmonary clearance of 99mTc-DTPA and the duration and magnitude of positive pressure applied tended to increase the value of k. ventilation (I), it is apparent that ventilator-induced barotrauma can also occur in the absence of acute lung injury (2, 3). Hyperventilation with assisted mechanical ventilation is frequently used as a therapeutic maneuver to reduce pulmonary vascular resistance in newborn infants with pulmonary hypertension (4) and to reduce cerebral edema in newborn and pediatric patients in the intensive care unit. In these cases where hyperventilation is used to produce hypocarbia and alkalosis, the lung parenchyma may be structually normal to begin with, but subsequently become injured from prolonged barotrauma (5). High peak airway pressures have been shown in animals to injure both the airway (6) and alveolar epithelium (7,8), as well as the capillary endothelium (9).The measurement of the pulmonary clearance of aerosolized solutes such as 99mTc-DTPA has been used in the assessment of the integrity of the pulmonary epithelium. In a variety of lung diseases such as adult respiratory distress syndrome (lo), interstitial lung disease (1 I), and Pneumocystis carinii infection (12) where damage to the pulmonary epithelium is present, the detection of an accelerated clearance rate of 99mTc-DTPA has been attributed to an increase in pulmonary epithelial permeability. However, other maneuvers such as an increase in lung volume (1 3) and acute exposure ...

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Solute permeability of the alveolar capillary barrier.

Cited by 74 publications

References 67 publications

Increased epithelial permeability in pulmonary fibrosis in relation to disease progression

Increased epithelial permeability in pulmonary fibrosis in relation to disease progression

Alveolus-capillary permeability on both normal and HIV seroreactive individuals

Effect of Mechanical Ventilation and Barotrauma on Pulmonary Clearance of 99mTechnetium Diethylenetriamine Pentaacetate in Lambs

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