Cerebrospinal fluid biomarkers in cardiac arrest survivors

The aim of this study was to investigate the levels of various cerebrospinal fluid (CSF) biomarkers related to neuronal damage, inflammation and amyloid β (Aβ) metabolism in patients resuscitated after an out-of-hospital cardiac arrest (CA).

CSF levels of neurofilament light protein (NFL), total tau (T-tau), hyperphosphorylated tau (P-tau), YKL-40, Aβ38, Aβ40, Aβ42, soluble amyloid precursor protein α and β (sAPPα and sAPPβ) were measured in 21 patients approximately two weeks after CA and in 21 age-matched neurologically healthy controls. The biomarker levels were also compared between patients with good and poor long-term clinical outcome according to Glasgow Outcome Scale (GOS), activities of daily living (ADL) and mini-mental state examination (MMSE), measuring neurologic function, daily functioning and cognitive function, respectively.

Patients with CA had a very marked increase in the CSF levels of NFL, T-tau and YKL-40 as compared with controls. The levels were increased at about 1200, 700 and 100%, respectively. NFL and T-tau were significantly higher in patients with poor outcome according to all three outcome measures. Patients with poor outcome according to GOS and ADL had higher levels of YKL-40. Levels of Aβ38, Aβ40, Aβ42, sAPPα and sAPPβ were lower in patients with a low MMSE score. P-tau was not significantly altered.

Biomarkers reflecting neuronal damage and inflammation, but not so much Aβ metabolism, were significantly altered in patients after a CA, and the changes were more pronounced in the groups with poor outcome. This calls for future larger studies to determine the prognostic potential of these biomarkers.