Concentrations of 30 different cytokines in the AH were analyzed using a Bio-Plex multiple assay (Bio-Plex Multiplex Immunoassay System; Bio-Rad Laboratories, Hercules, CA, USA). The measured cytokines were basic fibroblast growth factor (bFGF), eotaxin, granulocyte colony–stimulating factor (G-CSF), granulocyte macrophage colony–stimulating factor (GM-CSF), IFN-γ, IL-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, interferon-γ-inducible protein (IP-10), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, MIP-1β, platelet-derived growth factor (PDGF)-BB, regulated upon activation normal T-cell expressed and secreted (RANTES), TNF-α, VEGF-A, VEGF-C, VEGF-D, and placental growth factor (PlGF). The analysis was performed according to the manufacturer's instructions. Standard curves were generated using the Bio-Plex TM 200 System (Version 6.1; Bio-Rad Laboratories).