IL-1β, IL-6, TNF- α and CRP in Elderly Patients with Depression or Alzheimer’s disease: Systematic Review and Meta-Analysis

• Published in: Scientific reports Vol. 8; no. 1; pp. 12050 - 12
• Main Authors: Ng, Ada, Tam, Wilson W., Zhang, Melvyn W., Ho, Cyrus S., Husain, Syeda F., McIntyre, Roger S., Ho, Roger C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.08.2018; Nature Publishing Group
• Subjects: 13/21; 692/53/2423; 692/699/476/1414; Adaptor Proteins, Signal Transducing; Aged; Alzheimer Disease - blood; C-reactive protein; C-Reactive Protein - analysis; Cytokines; Depression; Depressive Disorder - blood; Geriatrics; Heterogeneity; Humanities and Social Sciences; Humans; Inflammation; Inflammation - blood; Interleukin 1; Interleukin 6; Interleukin-1beta - blood; Interleukin-6 - blood; Mental depression; Meta-analysis; Middle Aged; multidisciplinary; Proteins - analysis; Science; Science (multidisciplinary); Systematic review; Tumor necrosis factor-TNF; Tumor necrosis factor-α
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-30487-6

We carried out systematic review and meta-analysis to evaluate whether peripheral levels of pro-inflammatory markers including Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF- α) and C-Reactive Protein (CRP) are significantly higher in elderly with depression and Alzheimer’s disease. We searched Pubmed, PsycINFO and Embase, and thirty-four relevant studies (2609 with Depression, 1645 with Alzheimer’s disease and 14363 Controls) were included. Compared with controls, IL-1β (pooled standardized mean difference [SMD]: 0.642; 95% confidence interval [CI]: 0.078–1.206; significant heterogeneity: I 2  = 86.28%) and IL-6 (pooled SMD: 0.377; 95% CI: 0.156–0.598; significant heterogeneity: I 2  = 88.75%) were significantly elevated in depression. There was no difference in TNF-α (p = 0.351) and CRP (p = 0.05) between those with depression and controls. Compared with controls, IL-1β (pooled SMD: 1.37, 95% CI: 0.06–2.68, significant heterogeneity: I 2  = 96.01%) was significantly elevated in Alzheimer’s disease. There were no differences in IL-6 (p = 0.138), TNF-α (p = 0.451) and CRP (p = 0.07) between elderly with Alzheimer’s disease and controls. After Bonferroni adjustment, only IL-6 remained significantly higher in depression. Elderly with depression have higher IL-6 than controls, while those with Alzheimer’s disease did not have higher peripheral inflammatory markers.