Saghazadeh A, et al. - Researchers compared people with autism spectrum disorder (ASD) with control subjects without ASD with respect to circulating concentrations of pro-inflammatory cytokines in this meta-analysis. By systematically searching electronic databases from inception to February 2018, they identified 38 studies with a total of 2,487 participants (1,393 patients with ASD and 1,094 control subjects) as eligible for inclusion in the meta-analysis. As per the results, autistic patients vs control subjects display a higher concentration of pro-inflammatory cytokines interferon-γ, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. Latitude, age, and gender interact with peripheral alterations of associated pro-inflammatory cytokines as indicated by meta-regression analyses.