Department of Genetics, Wroclaw Medical University, 1 Marcinkowski Street, 50-368 Wroclaw, Poland.
Department of Psychiatry, Wroclaw Medical University, 10 Pasteur Street, 50-367 Wroclaw, Poland.
Schizophr Res. 2018 Feb;192:16-29. doi: 10.1016/j.schres.2017.04.015. Epub 2017 Apr 14.
The aim of this article was to perform a systematic review of studies investigating the association between peripheral levels of cytokines and C-reactive protein (CRP), cytokine gene polymorphisms and cognition in patients with schizophrenia and bipolar disorder (BD).
The following databases: PubMed, CINAHL Complete, Academic Search Complete, ERIC and Health Source: Nursing/Academic Edition databases were searched according to the PRISMA guidelines. We included studies that investigated the association between peripheral levels of CRP and cytokines, cytokine gene polymorphisms and cognitive performance in schizophrenia and/or BD patients. Subsequently, quality assessment of eligible publications was performed. Results were synthesized by discussing main findings around correlations between inflammatory markers and cognition.
Most consistent results indicate worse cognitive performance in schizophrenia patients with higher CRP levels. Less consistent evidence suggests better cognitive functioning of schizophrenia patients with higher levels of tumour necrosis factor-α (TNF-α). Evidence for the involvement of other cytokines in cognitive impairment in patients with schizophrenia is less convincing due to discordant results or scarcity of studies. Due to low number of studies, it is difficult to draw conclusions on the involvement of CRP and cytokine alterations in the development of cognitive deficits in BD. Single studies suggest the role of CRP, interleukin(IL)-1 receptor antagonist, IL-6 and TNF-α with its receptors in the development of cognitive impairment in BD.
Peripheral inflammation might be related to cognitive deficits in schizophrenia and BD. Unequivocal conclusions cannot be made due to methodological heterogeneity and low number of studies investigating particular cytokines.
本文旨在对研究外周细胞因子和 C 反应蛋白（CRP）、细胞因子基因多态性与精神分裂症和双相障碍（BD）患者认知之间关系的研究进行系统评价。
根据 PRISMA 指南，检索以下数据库：PubMed、CINAHL Complete、Academic Search Complete、ERIC 和 Health Source：Nursing/Academic Edition 数据库。我们纳入了研究外周 CRP 和细胞因子水平、细胞因子基因多态性与精神分裂症和/或 BD 患者认知功能之间关系的研究。随后，对合格出版物进行了质量评估。结果通过讨论炎症标志物与认知之间的相关性来综合。
大多数一致的结果表明，CRP 水平较高的精神分裂症患者认知表现较差。不太一致的证据表明，TNF-α 水平较高的精神分裂症患者认知功能更好。由于结果不一致或研究较少，其他细胞因子在精神分裂症患者认知障碍中的作用证据不太令人信服。由于研究数量较少，因此很难得出 CRP 和细胞因子改变参与 BD 认知缺陷发展的结论。单项研究表明 CRP、白细胞介素（IL）-1 受体拮抗剂、IL-6 和 TNF-α及其受体在 BD 认知障碍的发展中起作用。
外周炎症可能与精神分裂症和 BD 的认知缺陷有关。由于研究特定细胞因子的方法学异质性和研究数量较少，因此无法得出明确的结论。
