[Pulmonary alveolar proteinosis]

Pulmonary alveolar proteinosis is a rare disease characterised by excessive accumulation of surfactant components in the alveoli and the distal airways with minimum inflammatory reaction and fibrosis of pulmonary interstitium. Three clinical forms of pulmonary alveolar proteinosis are distinguished - congenital, primary and secondary. Results of ultrastructural, biochemical and functional analyses and studies performed on genetically modified mice support the presumption that accumulation of surfactant in pulmonary alveolar proteinosis is a result of a degradation disorder and of diminished clearance of the surfactant from the alveolar space rather than of excessive synthesis of surfactant components. Over the last 15 years, significant discoveries have been made which have helped to clarify the etiology and pathogenesis of the disease. A number of gene mutations have been discovered which lead to the development of congenital pulmonary proteinosis. Apart from impaired surfactant protein function, a key role in the development of pulmonary alveolar proteinosis is played by the signal pathway of granulocyte and macrophage colonies stimulating growth factor (GM-CSF) which is necessary for the functioning of alveolar macrophages and for surfactant homeostasis. The role of GM-CSF has been proven especially in primary pulmonary alveolar proteinosis which is currently considered an auto-immune disease involving the development of GM-CSF neutralising autoantibodies. In most cases, the prognosis for the disease in adult patients is good, even though there is a 10 to 15% rate of patients who develop respiratory failure. Total pulmonary lavage is considered to be the standard method of treatment. In recent years, recombinant human GM-CSF has been studied as a prospective therapy for the treatment of pulmonary alveolar proteinosis.