Serum brain-derived neurotrophic factor in coronary heart disease: Correlation with the T helper (Th)1/Th2 ratio, Th17/regulatory T (Treg) ratio, and major adverse cardiovascular events.

Background: Brain-derived neurotrophic factor (BDNF) exerts protective roles against dyslipidemia, atherosclerosis, and inflammation in cardiovascular diseases; meanwhile, it retards CD4+ T cell differentiation into T helper (Th)1 and Th17 cells. Hence, this study aimed to investigate the linkage of serum BDNF with Th1/Th2 ratio, Th17/regulatory T (Treg) ratio, and major adverse cardiovascular events (MACE) risk in the coronary heart disease (CHD) patients.

Methods: This prospective study detected serum BDNF in 210 CHD patients, 50 disease controls (DCs), and 50 healthy controls (HCs) using an enzyme-linked immunosorbent assay. For CHD patients only, the proportion of Th1, Th2, Th17, and Treg cells in blood CD4+ T cells was calculated by flow cytometry.

Results: The BDNF varied among CHD patients, DC, and HC (p < 0.001). Specifically, BDNF was declined in CHD patients compared with DCs (p < 0.001) and HCs (p < 0.001). In CHD patients, BDNF was negatively related to Th1 cells (p = 0.031), Th1/Th2 ratio (p = 0.026), Th17 cells (p = 0.001), and Th17/Treg ratio (p = 0.002). Concerning the prognosis, BDNF was reduced in patients with MACE occurrence compared to patients without MACE occurrence (p = 0.006). Furthermore, BDNF showed a trend (lacked statistical significance) to relate to longer MACE-free survival (p = 0.059). Besides, BDNF was related to the absence of obesity (p = 0.019), decreased total cholesterol (p = 0.043), low-density lipoprotein cholesterol (p = 0.019), C-reactive protein (p = 0.012), and Gensini score (p = 0.005).

Conclusions: Serum BDNF negatively correlates with Th1/Th2 ratio, Th17/Treg ratio, and estimates lower MACE risk in CHD patients.