Thirty-eight studies with total of 2487 participants (1393 patients with ASD and 1094 control subjects) were included in the meta-analysis; 13 for interferon (IFN)-γ, 17 for interleukin (IL)-1β, 22 for IL-6, 19 for tumor necrosis factor (TNF)-α, 4 for IL-1α, 6 for IL-2, 4 for IL-7, 8 for IL-8, 14 for IL-12, 3 for IL-15, 12 for IL-17, 3 for IL-18, 3 for IL-2 receptor, 3 for TNF-β, and 3 for IL-23.