Predictive analysis between cytokine profile and Aβ42, p‐Tau, and p‐Tau/Aβ42 levels in the cerebrospinal fluid of older adults with and without cognitive impairment

Abstract

AbstractBackgroundThe immune system activation observed in Alzheimer’s disease (AD) pathology contributes to its pathogenesis. It is proposed that ongoing interactions between β‐amyloid plaques, Tau protein, and neuroinflammatory mediators such as cytokines contribute to the maintenance of the inflammatory state in the brain. The aim was to evaluate whether cytokine profiles can predict variations in Aβ42, pTau, and pTau/Aβ42 cerebrospinal fluid (CSF) levels in older adults with and without objective cognitive impairment.MethodsEighty older adults were recruited, with a clinical diagnosis of AD dementia (36), with Mild Cognitive Impairment (MCI) (24), and without objective cognitive impairment (20). CSF levels of Aβ42, pTau, and 27 cytokines were assessed by the Luminex xMAP technique. Significant associations between Aβ42, p‐Tau, and p‐Tau/Aβ42 CSF levels and cytokines were explored in multiple linear regression analyses adjusted for age, education, and APOE ε4 carrier status.ResultsWe found that Granulocyte and Macrophage colony‐stimulating factors (GM‐CSF) (β = ‐.375; p = .010) and IL‐6 (β = ‐.370; p = .014) had a negative significant association with Aβ42, while IL‐8 (β = .452; p = .002) and IL‐4 (β = .488; p = .001) had positive significant association and higher magnitude of effect on Aβ42. For pTau, age (β = .240; p = .029), IL‐2 (β = .314; p = .012) and ε4 allele (β = 0.349; p = .002) had a positive significant association. The variable with the greatest magnitude of the effect was the presence of the ε4 allele. For the p‐Tau/Aβ42 ratio, G‐CSF (β = .423; p = .003) and GM‐CSF (β = .317; p = .019) had a significant positive association, while for IL‐8 (β = ‐.554; p = .001) and IL‐12 (β = ‐.334; p = .019) the association was significantly negative. IL‐8 had the greatest magnitude of effect on p‐Tau/Aβ42 ratio values.ConclusionThe higher levels of IL‐4 and the IL‐8 associated to a higher Aβ42 suggest their role at the beginning of the disease. On the other hand, the lower level of IL‐8 associated with a higher p‐Tau/Aβ42 suggests its inactivation as the disease progresses. Conversely, the higher levels of GM‐CSF associated with higher p‐Tau/Aβ42 suggests a more robust recruitment of the immune cell system at later stages.Reference: Aksnes, M., et al., (2021). Associations of cerebrospinal fluid amyloidogenic nanoplaques with cytokines in Alzheimer’s disease. Translational Neurodegeneration.