Measurement of cytokine levels in BALF and SHS
The concentrations of interleukin (IL)-4, IL-13, interferon (IFN)-γ, and IL-10 in BALF and SHS were measured by sandwich enzyme-linked immunosorbent assay (ELISA), in accordance with the manufacturer’s instructions (eBioscience Co., San Diego, CA, USA). Values were interpolated from standard curves using recombinant cytokines and expressed in pg/mL.