Pulmonary and Systemic Hepatocyte Growth Factors in Patients With COPD

Overview

The role of HGF and KGF in COPD is poorly known. Plantier et al found that cultured fibroblasts harvested from patients with emphysema produced less HGF (but similar amounts of KGF) than controls, and Bonay et al found a direct relationship between the severity of airflow obstruction and HGF mRNA content in lung samples of smokers. These two studies suggest, therefore, that the pulmonary regulation of HGF may be abnormal in patients with COPD. However, both HGF and KGF can also be released by extra-pulmonary organs, thus having the potential to act systemically. Given the current clinical relevance attributed to the systemic effects of COPD, in this study we compared the levels of HGF and KGF in the pulmonary (bronchoalveolar lavage (BAL) fluid) and systemic compartment (circulating blood) of smokers with and without COPD and never smokers.

Background: The potential role of growth factors in COPD has begun to be addressed only recently and is still poorly understood. In this study we investigate potential abnormalities of hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF) in patients with COPD. Methods: To this end, we compared the levels of HGF and KGF, measured by ELISA, in bronchoalveolar lavage (BAL) fluid and in serum in 18 patients with COPD (62 ± 2 yrs, FEV1 57 ± 4% ref, X ± SEM), 18 smokers with normal lung function (58 ± 2 yrs., FEV1 90 ± 4% ref) and 8 never smokers (67 ± 7 yrs, 94 ± 4% ref). Results: We found that, in BAL, HGF levels were higher in patients with COPD than in the other two groups whereas, in serum, HGF concentration was highest in smokers with normal lung function (p\<0.01). KGF levels were not significantly different between groups, neither in blood nor in BAL, (most values were below the detection limit). Conclusions: These results highlight a different response of HGF in BAL and serum in smokers with and without COPD that may be relevant for tissue repair in COPD.

Conditions