Diagnostic accuracy of IL-6, IL-10 and TNF-α cytokine levels in patients
with mild cognitive impairment: Systematic review and meta-analysis
Abstract
Introduction: There is growing evidence suggesting an association
between Neurodegeneration and Inflammation playing a role in the
pathogenesis of age-associated diseases, including Alzheimer’s disease
(AD) and Mild Cognitive Impairment (MCI). A systematic review and
meta-analysis were performed to verify evidence on the diagnostic
accuracy parameters of the inflammatory cytokines Interleukin-6 (IL-6),
Interleukin-10 (IL-10) and Tumor Necrosis Factor (TNF-α). Method: A
search of Medline, Scielo, Web of Science and Science Direct databases
was performed and 9 observational studies associated with peripheral
inflammatory biomarkers in CCL were identified. Mean (± SD)
concentrations of these biomarkers and values of true positives (VP),
true negatives (VN), false positives (FP) and false negatives (FN) for
CCL and healthy controls (CS) were extracted from these studies. Result:
Significantly higher levels of IL-10 were observed in subjects in the
MCI group and Mini Mental State Examination (MMSE) scores were lower
compared to CS. For the other investigations, no differences were found
between the groups. Our meta-analysis for the TNF-α biomarker revealed
high heterogeneity between studies in terms of sensitivity and
specificity. Limitations: Lack of essential data in observational
studies, which directly impacted the number of included studies.
Conclusion: These findings do not support the involvement of
inflammatory biomarkers for detection of MCI, although significant
heterogeneity was observed. More studies are needed to evaluate the role
of these cytokines in MCI, as well as in other stages of cognitive
decline and all-cause dementias.