Pneumoproteinaemia: a new perspective in the assessment of lung disorders

Here we make the hypothesis that the determination of the concentration of lung specific secretory proteins in serum or pneumoproteinaemia could be used in the evaluation of lung disorders with a similar utility as proteinuria in kidney diseases involving the glomeruli. Human and experimental data indicate that comparable structural and functional features govern the passage of proteins across the lung epithelium/blood barrier and the glomerular filter. The concentrations in serum of some lung-specific secretory proteins, such as the bronchiolar Clara cell 16 kDa protein (CC16) and alveolar surfactant-associated proteins A and B (SP-A and SP-B, respectively), might be used to assess the integrity of the bronchoalveolar/blood barrier known to be disrupted in many lung disorders. In addition, if this barrier is intact or slightly compromised, these proteins might serve as peripheral markers to detect changes in secretory epithelial cells in the lung.