Inflammatory Cytokine Alterations in Schizophrenia: A Systematic Quantitative Review

well as IL-2, soluble IL-2 receptor (sIL-2R), IL-1, IL-1 receptor antagonist (IL-1RA), tumor necrosis factor-alpha (TNF-), IL-6, soluble IL-6 receptor(sIL-6R),andIL-10.TheresultsshowthatanincreaseoccursininvivoIL-1RA,sIL-2R,andIL-6andadecreaseoccursininvitroIL-2in schizophrenia. No significant effect sizes were obtained for the other cytokines. Conclusions: Thesefindingsprovidethefirstevidenceofestablishmentofaninflammatorysyndromeinschizophrenia,whichrefutesthe currenthypothesisofaTh2slant.Caveatsarepresentedtodatainterpretation,includingtheroleofstressandtheeffectofweightgainthat develops in schizophrenia.