Brain-Derived Neurotrophic Factor Levels in Children with Asthma and Isolated Chronic Cough

Studies show that neurogenic inflammation is implicated in the pathogenesis of chronic cough. Neurotrophins (NTs) regulate the synthesis of neuropeptides, which cause neurogenic inflammation. There is growing evidence suggesting their involvement in airway inflammation. The role of the brain-derived neurotrophic factor (BDNF), a member of the NT family, is not clear in chronic cough. The aim of this study was to evaluate the role of BDNF in children with nonspecific isolated chronic cough and to compare the differences between patients with asthma and healthy controls. In this case-control study, we included 30 patients with chronic cough (5-15 years) as the patient group. As the control group, 28 asthma patients under control, 30 children with asthma attacks, and 30 healthy children were included. Serum BDNF levels were measured by ELISA in all groups. The median of BDNF levels was 708.12 pg/mL (155-974) in the patient group, 952.94 pg/mL (220-1,018) in the controlled asthma group, 852.09 pg/mL (355-1,036) in the uncontrolled asthma patients, and 572.65 pg/mL (213-818) in the healthy children group. There were differences in the patient group and control groups regarding the BDNF levels (for the patient group and the controlled asthma group, P = 0.0014; for the patient group and the uncontrolled asthma patients, P = 0.0009; for the patient group and healthy children group, P = 0.05). The BDNF levels of asthma patients were statistically different from healthy children (P = 0.0001). Neurogenic inflammation was implicated in the pathogenesis of chronic cough. In patients with chronic cough, high BDNF levels may support the presence of asthma.