Serum levels of Tumor Necrosis Factor-α (TNF-α), Monocyte chemotactic protein-1 (MCP-1), Vascular endothelial growth factor (VEGF), Epidermal growth factor (EGF), forced expiratory volume-one second (FEV<sub>1</sub>) and respiratory symptoms including; Chest wheeze (CW), night wheeze (NW), night cough (NC) and cough and wheeze during exercise (ECW) were assessed at the baseline (step 0), one and two months after starting treatment (step I and II, respectively).
IL8-rs4073AT, VEGFA-rs2146323AA and NFKBIA-rs2233419AG were associated with a significantly increased risk of developing recurrent wheezing (p = 0.04, p = 0.04 and p = 0.03), whereas TLR3-rs3775291TC was associated with a significantly reduced risk (p = 0.03).