Elevated cerebrospinal fluid and serum YKL-40 levels are not associated with symptomatic vasospasm in patients with aneurysmal subarachnoid haemorrhage

Biomarkers in aneurysmal subarachnoid hemorrhage: A short review

Poor outcomes of aneurysmal subarachnoid hemorrhage (aSAH) can be the result of the initial catastrophic event or the many acute or delayed neurological complications. Recent evidence suggests that some molecules play a critical role in both events, through some unknown pathways involved. Understanding the role of these molecules in these events could allow to improve diagnostic accuracy, guide management, and prevent long-term disability in aSAH. Here we present the studies on aSAH biomarkers present in current medical literature, highlighting their roles and main results.

Risk factors of chronic shunt dependent hydrocephalus following aneurysmal subarachnoid haemorrhage

BACKGROUND

Acute and delayed hydrocephalus are common sequelae following aneurysmal subarachnoid haemorrhage.

AIMS

To identify factors that may influence cerebrospinal fluid diversion either temporarily or permanently in order to guide clinical judgement.

METHODS

Patients treated in our unit between 01/2014 until 12/2017 with aneurysmal SAH were retrospectively analysed to identify significant factors predisposing to CSF diversion.

RESULTS

242 patients were analysed (180F, 62M) with mean age 56 years over 36 months. 31 % patients had EVD inserted and 12 % received shunts. 19 patients had EVDs prior to their shunt. 11.8 % patients received serial lumbar puncture. Higher WFNS (P<0.05) and Fisher grade (P<0.05) were associated with increased rates of EVD insertion and shunting. Higher WFNS and Fisher scores were observed within posterior circulation aneurysms. Lower GCS and higher WFNS had significant correlation towards early shunting (P<0.05). EVD infection predisposes to higher rates of shunt conversion (P<0.05). Factors predisposing to post aneurysmal subarachnoid haemorrhage hydrocephalus and CSF drainage included aneurysm location in posterior circulation (P<0.05), increasing relative need of EVD insertion by 185 % and shunting by 240 %. Basilar tip aneurysms had even higher incidence of shunting (42 % of all posterior circulation aneurysms). Posterior circulation aneurysms had significantly higher risk of requiring EVD insertion, with 48 % of aneurysms in the posterior circulation compared to 25 % in the anterior circulation requiring EVDs (P<0.05). Incidence of posterior circulation aneurysms increases with age (>50(P<0.05)).

CONCLUSION

Our study demonstrated factors that may predict chronic post aneurysmal subarachnoid haemorrhage hydrocephalus (PASHH) in patients that will ultimately need timely intervention.

Chitinase-3-like protein 1 may be a potential biomarker in patients with drug-resistant epilepsy

The mechanisms of the pathogenesis of epilepsy remain unclear. Recent research shows that the inflammatory process occurring in the brain may be a common and critical mechanism of seizures. Chitinase-3-like protein 1 (CHI3L1 or YKL-40) is a newly discovered inflammatory factor. We aimed to evaluate the role of YKL-40 as a biomarker for epilepsy. 124 subjects were classified as control group (n = 23), new-diagnosis epilepsy group (NDE, n = 34), drug responsive epilepsy group (DPE, n = 37), and drug-resistant epilepsy group (DRE, n = 30) YKL-40 was measured by ELISA in serum and cerebrospinal fluid (CSF). The concentrations of serum and CSF YKL-40 and its diagnostic accuracy for epilepsy were analysed. Patients with DRE had higher concentrations of YKL-40 in serum and CSF, while patients with NDE and DPE had increased YKL-40 levels in CSF but not serum in comparison with control. Moreover, serum and CSF YKL-40 provide high diagnostic accuracy for DRE. YKL-40 may play a possible pathogenic role in epilepsy. YKL-40 may represent a potential biomarker of brain inflammation in patients with DRE.

Vascular diseases and bleedings

Diseases of the central nervous system that are caused by an underlying vascular pathology typically result in either hemorrhage or ischemia. Most prominent entities include spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. For anatomic reasons, cerebrospinal fluid (CSF) qualifies as body fluid for the exploration of biomarkers in these disorders. Even though in subarachnoid hemorrhage a few CSF parameters have been established for routine diagnostic purposes, there is still an unmet need and broad interest in the identification of molecules that would allow further insight into disease mechanisms and supplement patients' medical care. This chapter provides an overview on what is presently known about CSF biomarkers in spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. We recapitulate current evidence on established diagnostic tests, discuss the role of various CSF molecules in the pathophysiology of these diseases, and illuminate their potential use in future clinical practice. Furthermore, we address methodologic aspects as well as shortcomings of research in this field.

YKL-40: a novel prognostic fluid biomarker for preclinical Alzheimer's disease

BACKGROUND

Disease-modifying therapies for Alzheimer's disease (AD) would be most effective during the preclinical stage (pathology present, cognition intact) before significant neuronal loss occurs. Therefore, biomarkers that detect AD pathology in its early stages and predict dementia onset and progression will be invaluable for patient care and efficient clinical trial design.

METHODS

AD-associated changes in cerebrospinal fluid (CSF) were measured using two-dimensional difference gel electrophoresis and liquid chromatography tandem mass spectrometry. Subsequently, CSF YKL-40 was measured by enzyme-linked immunosorbent assay in the discovery cohort (n = 47), validation cohort (n = 292) with paired plasma samples (n = 237), frontotemporal lobar degeneration (n=9) [corrected], and progressive supranuclear palsy (PSP; n = 6). Immunohistochemistry was performed to identify source(s) of YKL-40 in human AD brain.

RESULTS

Discovery and validation cohorts, showed higher mean CSF YKL-40 in very mild and mild AD-type dementia (Clinical Dementia Rating [CDR] 0.5 and 1) versus control subjects (CDR 0) and PSP subjects. Importantly, CSF YKL-40/Aβ42 ratio predicted risk of developing cognitive impairment (CDR 0 to CDR > 0 conversion), as well as the best CSF biomarkers identified to date, tau/Aβ42 and p-tau 181/Aβ42. Mean plasma YKL-40 was higher in CDR 0.5 and 1 versus CDR 0, and correlated with CSF levels. YKL-40 immunoreactivity labeled astrocytes near a subset of amyloid plaques, implicating YKL-40 in the neuroinflammatory response to Aβ deposition.

CONCLUSIONS

These data demonstrate that YKL-40, a putative indicator of neuroinflammation, is elevated in AD and, together with Aβ42, has potential prognostic utility as a biomarker for preclinical AD.

Proteomic biomarker discovery in cerebrospinal fluid for cerebral vasospasm following subarachnoid hemorrhage

Currently, there are no established biomarkers for diagnosing preclinical vasospasm or monitoring its progression. Two areas of extensive biomarker research are neuroimaging and biochemical markers in body fluids, such as cerebrospinal fluid (CSF). We performed a review of studies conducted over the past 2 decades summarizing the science to date and the evolution of CSF biomarkers in subarachnoid hemorrhage (SAH). A Medline search performed using the search terms "subarachnoid hemorrhage marker AND cerebrospinal fluid," limited to the period January 1, 1990 to June 1, 2009, returned 62 references. Abstracts that did not deal primarily with SAH and potential markers in the CSF of humans were excluded, resulting in 27 abstracts. Only articles providing sufficient information for a substantiated analysis were selected. In addition, articles identified in reference lists of individual articles were selected if considered appropriate. Evidence was classified as class I-IV and recommendations were classified as category A-C according to European Federation of Neurological Societies guidelines. We evaluated CSF markers in SAH patients and divided them into 3 categories: A, markers with auspicious value; B, candidate markers; and C, noncandidate markers. Category A markers included tumor necrosis factor (TNF)-α, soluble tumor necrosis factor receptor I (sTNFR-I), and interleukin (IL)-1 receptor antagonist (IL-1ra), as well as the neurofilament proteins NFL and NfH. Category B markers included apolipoprotein E (ApoE), F2-isoprostane (F2-IsoP), NOx, and the indicators for thrombin activity membrane-bound tissue factor (mTF) and thrombin-antithrombin III complex (TAT) for neurologic outcome prediction, as well as E-selectin, lactate, alpha-II spectrin breakdown products (SBDPs), asymmetric dimethyl-L-arginine (ADMA), and monocyte chemoattractant protein-1 (MCP-1) for vasospasm prognostication. Category C markers included S100B, platelet-derived growth factor (PDGF), YKL-40, chitotriosidase, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and IL-8. Cytokines and their receptors, as well as neuronal intracellular proteins, seem to be potential markers for outcome determination in patients after SAH.

Plasma YKL-40: a potential new cancer biomarker?

YKL-40, a 40-kDa secreted glycoprotein, with its gene located on chromosome 1q32.1, is produced by cancer cells and inflammatory cells and has a role in inflammation, cell proliferation, differentiation, protection against apoptosis, stimulation of angiogenesis and regulation of extracellular tissue remodeling. Plasma levels of YKL-40 are elevated in a subgroup of patients with primary or advanced cancer compared with age-matched healthy subjects, but also in patients with many different diseases characterized by inflammation. Elevated plasma YKL-40 levels are an independent prognostic biomarker of short survival. There is still insufficient evidence to support its value outside of clinical trials as a screening tool, prognosticator of survival, predictor of treatment response and as a monitoring tool in the routine management of individual patients with cancer or diseases characterized by inflammation. Large prospective, longitudinal clinical cancer studies are needed to determine if plasma YKL-40 is a new cancer biomarker, or is mainly a biomarker of inflammation.