Do Surfactant Proteins Have Prognostic Value in Chronic Obstructive Pulmonary Disease?

Chronic obstructive pulmonary disease (COPD) is an important problem of public health worldwide, with high morbidity and mortality, and with huge health economic burdens. There is a paucity of prognostic beneficial therapies. The development of novel pharmaceutical therapies in COPD is hampered by the absence of lung-specific biomarkers, which could serve as predictors of prognosis of COPD or as surrogate endpoints. Surfactant proteins (SP) would possibly serve as such a biomarker. The levels of these proteins fluctuate in the serum and in the lung of patients with COPD, dependent of the disease stage. This review will provide an overview of the functional characteristics of three surfactant-associated proteins, SP-A, SP-B and SP-D, their possible roles as prognostic predictors of COPD, and their relationship with tobacco smoking. So far, genetic variants of SP-B and serum levels of SP-D showed to be predictors of exacerbations of COPD. Future studies are needed to further elucidate the prognostic possibilities and the underlying mechanisms of surfactant-associated proteins in both the lung and blood