Physiological and biochemical markers of alveolar epithelial barrier dysfunction in perfused human lungs.
To study air space fluid clearance (AFC) under conditions that resemble the clinical setting of pulmonary edema in patients, we developed a new perfused human lung preparation. We measured AFC in 20 human lungs rejected for transplantation and determined the contribution of AFC to lung fluid balance. AFC was then compared with air space and perfusate levels of a biological marker of epithelial injury. The majority of human lungs rejected for transplant had intact basal (75%) and beta(2)-adrenergic agonist-stimulated (70%) AFC. For lungs with both basal and stimulated AFC, the basal AFC rate was 19 +/- 10%/h, and the beta(2)-adrenergic-stimulated AFC rate was 43 +/- 13%/h. Higher rates of AFC were associated with less lung weight gain (Pearson coefficient -0.90, P < 0.0001). Air space and perfusate levels of the type I pneumocyte marker receptor for advanced glycation end products (RAGE) were threefold and sixfold higher, respectively, in lungs without basal AFC compared with lungs with AFC (P < 0.05). These data show that preserved AFC is a critical determinant of favorable lung fluid balance in the perfused human lung, raising the possibility that beta(2)-agonist therapy to increase edema fluid clearance may be of value for patients with acute lung injury and pulmonary edema. Also, although additional studies are needed, a biological marker of alveolar epithelial injury may be useful clinically in predicting preserved AFC.
Frank
James A
JA
Department of Medicine, University of California, San Francisco, California, USA. james.frank@ucsf.edu
Briot
Raphael
R
Lee
Jae Woo
JW
Ishizaka
Akitoshi
A
Uchida
Tokujiro
T
Matthay
Michael A
MA
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D015824:Blood-Air Barrier / Q000187:drug effects / Q000503:physiopathology*; D001826:Body Fluids; D003710:Demography; D004848:Epithelium / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D016040:Lung Transplantation; D008297:Male; D010313:Partial Pressure; D010477:Perfusion / Q000379:methods*; D011654:Pulmonary Edema / Q000503:physiopathology; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000378:metabolism; D013997:Time Factors; D014019:Tissue Donors
D000318:Adrenergic beta-Agonists; D015415:Biomarkers; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic