Does dust-associated pulmonary alveolar proteinosis represent an autoimmune disorder?

The role of autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF) in the development of secondary pulmonary alveolar proteinosis (PAP) in patients exposed to occupational and environmental dust remains unclear. Herein, we describe two cases of secondary PAP who had GM-CSF antibodies and absence of STAT5 phosphorylation index, suggestive of a potential relationship between the appearance of GM-CSF antibodies and environmental dust exposure. However, whether the presence of GM-CSF antibodies is a part of the pathological process or represents an epiphenomenon is currently unknown. In this report, we would like to present two cases supporting these new data and briefly discuss the possible role of autoimmune mechanisms in the development of secondary PAP. Am. J. Ind. Med. 60:591-597, 2017. © 2017 Wiley Periodicals, Inc.