Serum CRP detection was conducted using the imagetype automatic biochemical analyzer (Beckman Coulter Inc., USA). The kit was also provided by the same company. Serum cytokines, namely IL-2, IL-4, IL-6, IL-10, and IFN-γ were tested using an enzyme-linked immunosorbent assay (ELISA; Ex-cell). The experimental methods were in accordance with the instructions of the manufacturer in the reagent kit.