Plasma Inflammatory Biomarkers Are Associated With Poststroke Cognitive Impairment: The Nor-COAST Study

Abstract

Background: Inflammation is proposed to be involved in the pathogenesis of poststroke cognitive impairment. The aim of this study was to investigate associations between concentrations of systemic inflammatory biomarkers after ischemic stroke and poststroke cognitive impairment. Methods: The Nor-COAST study (Norwegian Cognitive Impairment After Stroke) is a prospective observational multicenter cohort study, including patients hospitalized with acute stroke between 2015 and 2017. Inflammatory biomarkers, including the TCC (terminal C5b-9 complement complex) and 20 cytokines, were analyzed in plasma, collected at baseline, 3-, and 18 months poststroke, using ELISA and a multiplex assay. Global cognitive outcome was assessed with the Montreal Cognitive Assessment (MoCA) scale. We investigated the associations between plasma inflammatory biomarkers at baseline and MoCA score at 3-, 18-, and 36-month follow-ups; the associations between inflammatory biomarkers at 3 months and MoCA score at 18- and 36-month follow-ups; and the association between these biomarkers at 18 months and MoCA score at 36-month follow-up. We used mixed linear regression adjusted for age and sex. Results: We included 455 survivors of ischemic stroke. Higher concentrations of 7 baseline biomarkers were significantly associated with lower MoCA score at 36 months; TCC, IL (interleukin)-6, and MIP (macrophage inflammatory protein)-1α were associated with MoCA at 3, 18, and 36 months ( P <0.01). No biomarker at 3 months was significantly associated with MoCA score at either 18 or 36 months, whereas higher concentrations of 3 biomarkers at 18 months were associated with lower MoCA score at 36 months ( P <0.01). TCC at baseline and IL-6 and MIP-1α measured both at baseline and 18 months were particularly strongly associated with MoCA ( P <0.01). Conclusions: Higher concentrations of plasma inflammatory biomarkers were associated with lower MoCA scores up to 36 months poststroke. This was most pronounced for inflammatory biomarkers measured in the acute phase following stroke. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02650531.

Current and Future Treatments of Vascular Cognitive Impairment

“…14,18 The mechanisms driving delayed-onset cognitive decline are multiple and may include underlying cSVD, AD, other concurrent or incident medical comorbidities (eg, hypertension, diabetes, seizures, chest infection), inflammatory responses that are triggered by the stroke event (eg, neuroinflammation), and other unknown processes. 14,16,18,19 perfusion due to impaired neurovascular coupling and arteriole stiffening. In addition, recent studies showed that the glymphatic-meningeal lymphatic system is also impaired secondary to aging and other risk factors of cSVD.…”

“…14,18 The mechanisms driving delayed-onset cognitive decline are multiple and may include underlying cSVD, AD, other concurrent or incident medical comorbidities (eg, hypertension, diabetes, seizures, chest infection), inflammatory responses that are triggered by the stroke event (eg, neuroinflammation), and other unknown processes. 14,16,18,19…”

Exploring vascular contributions to cognitive impairment and dementia (ENIGMA): protocol for a prospective observational study

“…Further, some magnetic resonance imaging (MRI) markers have been associated with PSCI including brain atrophy and markers of cerebral small vessel disease (cSVD) such as white matter hyperintensities and cerebral microbleeds [ 14 , 15 ]. In addition, several blood-derived biomarkers have also shown promise as predictors of PSCI [ 16 – 18 ]. Despite these advances in the field, the exact underlying pathophysiology behind PSCI is not well understood.…”

Infection, Inflammation, and Poststroke Cognitive Impairment

“…Stroke‐associated biomarkers of inflammation may also be associated with PSCI, 17 , 18 , 19 including C‐reactive protein (CRP), 19 neutrophil/lymphocyte ratio (NLR), 17 erythrocyte sedimentation rate, 20 terminal C5b‐9 complement complex, interleukin‐6, and macrophage inflammatory protein‐1α. 21 Ischemia leads to the induction of proteases and free radicals, blood–brain barrier opening, and, ultimately, myelin breakdown and oligodendrocyte death. 22 A more proinflammatory immune signature in peripheral blood at 2 days after stroke has been linked to PSCI within the first year, 23 and acute inflammation appears more predictive than chronic inflammation for poststroke cognitive outcome at 36 months.…”

“… 22 A more proinflammatory immune signature in peripheral blood at 2 days after stroke has been linked to PSCI within the first year, 23 and acute inflammation appears more predictive than chronic inflammation for poststroke cognitive outcome at 36 months. 21 …”