The brain-derived neurotrophic factor (BDNF) is a member of the neurotrophins, found to be involved in lung health and diseases.  In the present study we assessed the serum level of BDNF in 57 patients with COPD and in 19 control individuals and explored its possible association with the pulmonary function test (PFT) parameters and disease stage.  

Results: There was no significant difference in the serum levels of BDNF between patients and controls (p=0.705). We found that the serum BDNF was in a weak statistically significant negative correlation with the age of the patients (Rho= - 0.279, p=0.036) and in a statistically marginal negative correlation with the age of disease onset (Rho= -0.244, p=0.063). These correlations were stronger in male patients (Rho= -0.398, p=0.009 and Rho= -0.340, p=0.010). In the whole group of patients there were no correlation between serum BDNF and the PFT parameters (p=0.231 for FEV1%pr. and p=0.271 for FEV1/FVC %). However, when the patients were grouped according to smoking habits, there was a strong positive correlation between BDNF and FEV1%pr. (Rho=0.501, p=0.048), while in ex/current smokers there were statistically significant negative correlations with FEV1%pr. (Rho= -0.468, p=0.003) and with FEV1/FVC% (Rho= -0.331, p=0.040). Non-smokers in GOLD stage II had significantly higher BDNF than patients with stage III/IV (p=0.042), while an opposite association was seen in ex/current smokers (p=0.0008).

The results of our study suggest that the BDNF might have opposite effects on COPD progression in individuals with different smoking history.

The work was supported by Project 6/2021, MF, TrU, Stara Zagora.