Perioperative time course of matrix metalloproteinase-9 (MMP-9), its tissue inhibitor TIMP-1 & S100B protein in carotid surgery

Increased serum level of high sensitivity troponin T even prior to surgery can predict adverse events during carotid endarterectomy

OBJECTIVES

Perioperative stress affects the outcome of carotid endarterectomy performed under regional anesthesia. Here we aimed to explore the temporal profile of the stress marker cortisol and its relationship to high-sensitivity troponin-T, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and S100B as an indicator of blood-brain barrier alteration in the systemic circulation.

METHODS

Prospective part of the study: a total of 31 patients with significant carotid stenosis scheduled for carotid endarterectomy in regional anesthesia were enrolled. Follow-up part of the study and retrospective analysis of the outcome: each patient was followed up to five years and morbidity as well as mortality data were collected from an electronic database. Blood samples from each patient were serially taken; prior to surgery (T1), at the time of reperfusion (T2), 24 h (T3) and 72 h later postoperatively (T4), then the plasma concentration of each biomarker was measured. Besides, the clinical and surgical factors and perioperative adverse events were recorded.

RESULTS

More positive correlations were found between: the early change of S100B (T2-T1) and late change in plasma cortisol level (T4-T3) (r = 0.403; p < 0.05); the early change of cortisol (T2-T1) and the early postoperative change of plasma matrix metalloproteinase-9 level (T3-T2) (r = 0.432; p = 0.01); the plasma concentration of tissue inhibitor of metalloproteinase-1 at 24 postoperative hours and the late change in plasma high-sensitivity troponin-T level (T4-T3) (r = 0.705; p < 0.001). Five patients needed an intraoperative shunt in whom the high-sensitivity troponin-T was elevated even prior to surgery, but definitive stroke never occurred. Plasma matrix metalloproteinase-9 concentration at reperfusion independently predicted the five-year mortality with a cut-off value of 456 ng/ml (sensitivity: 86%, specificity: 84%, area 0.887, p = 0.002).

CONCLUSIONS

A higher intraoperative change in S100B level reflecting carotid endarterectomy induced acute silent brain ischemia was associated with more pronounced post-operative change of cortisol. An early elevation of cortisol was found to be associated with a delayed increase of matrix metalloproteinase-9. Importantly, an increased high-sensitivity troponin-T even prior to carotid endarterectomy may predict clamp intolerance, and elevated matrix metalloproteinase-9 at reperfusion suggests a poor outcome.

Association of biomarker S100B and cerebral oximetry with neurological changes during carotid endarterectomy performed in awake patients

Background: This study attempted to correlate neurological symptoms in awake patients undergoing carotid endarterectomy (CEA) under local anaesthesia (LA) with serum concentration of S100B protein and measurement of cerebral oximetry with near-infrared spectroscopy (NIRS). Patients and methods: A total of 64 consecutive CEAs in 60 patients operated under LA during an 18-month period were prospectively evaluated. A cerebral oximeter was used to measure cerebral oxygen saturation (rSO₂) before and after cross-clamping along with serum concentration of the S100B protein. Selective shunting was performed when neurological changes occurred, regardless of NIRS. Neurological deterioration occurred (neurological symptoms group) in 7 (10.9 %) operations. In 57 (89.1 %) operations, the patients were neurologically stable (no neurological symptoms group). Results: The neurological symptoms that occurred after clamping correlated with an increase in the serum level of S100B (P = .040). The cut-off of 22.5 % of S100B increase was determined to be optimal for identifying patients with neurological symptoms. There was no correlation between rSO₂ decline and neurological symptoms (P = .675). Two (3.1 %) perioperative strokes occurred. Conclusions: We found a correlation between neurological symptoms and serum S100B protein increase. However, because of the long evaluation time of serum S100B, this monitoring technique cannot be performed during CEA.

Comparison of the perioperative time courses of matrix metalloproteinase-9 (MMP-9) and its inhibitor (TIMP-1) during carotid artery stenting (CAS) and carotid endarterectomy (CEA)

Background

Our aim was to compare the perioperative time courses of matrix metalloproteinase-9 (MMP-9) and its inhibitor (TIMP-1) in during carotid endarterectomy (CEA) and carotid artery stenting (CAS).

Methods

In our prospective study, twenty-five patients who were scheduled to undergo CAS were enrolled. We used a matched, historical CEA group as controls. Blood samples were collected at four time points: T1: preoperative; T2: 60 min after stent insertion; T3: first postoperative morning; and T4: third postoperative morning. Plasma MMP-9 and TIMP-1 levels were measured by ELISA.

Results

In the CEA group, the plasma levels of MMP-9 were significantly elevated at T3 compared to T1. In the CAS group, there was no significant difference in MMP-9 levels in the perioperative period. MMP-9 levels were significantly higher in the T3 samples of the CEA group compared to the CAS group. Significantly lower TIMP-1 levels were measured in both groups at T2 than at T1 in both groups. MMP-9/TIMP-1 at T3 was significantly higher than that at T1 in the CEA group compared to both T1 and the CAS group.

Conclusions

CAS triggers smaller changes in the MMP-9-TIMP-1 system during the perioperative period, which may correlate with a lower incidence of central nervous system complications. Additional studies as well as cognitive and functional surveys are warranted to determine the clinical relevance of our findings.

Trial registration

NIH U.S. National Library of Medicine, Clinicaltrials.gov,NCT03410576, 24.01.2018, Retrospectively registered

Looking for novel, brain-derived, peripheral biomarkers of neurological disorders

The role of blood brain barrier (BBB) is to preserve a precisely regulated environment for proper neuronal signaling. In many of the central nervous system (CNS) pathologies, the function of BBB is altered. Thus, there is a necessity to evaluate a fast, noninvasive and reliable method for monitoring of BBB condition. It seems that revealing the peripheral diagnostic biomarker whose release pattern (concentration, dynamics) will be correlated with clinical symptoms of neurological disorders offers significant hope. It could help with faster diagnosis and efficient treatment monitoring. In this review we summarize the recent data concerning exploration of potential new serum biomarkers appearing in the peripheral circulation following BBB disintegration, with an emphasis on epilepsy, traumatic brain injury (TBI) and stroke. We consider the application of well-known proteins (S100β and GFAP) as serum indicators in the light of recently obtained results. Furthermore, the utility of molecules like MMP-9, UCHL-1, neurofilaments, BDNF, and miRNA, which are newly recognized as a potential serum biomarkers, will also be discussed.

Association of S100B polymorphisms and serum S100B with risk of ischemic stroke in a Chinese population

The levels of serum S100B were elevated in patients with ischemic stroke (IS), which may be a novel biomarker for diagnosing IS. The aim of this study was to investigate the association of S100B polymorphisms and serum S100B with IS risk. We genotyped the S100B polymorphisms rs9722, rs9984765, rs2839356, rs1051169 and rs2186358 in 396 IS patients and 398 controls using polymerase chain reaction-single base extension (SBE-PCR). Serum S100B levels were measured by enzyme-linked immunosorbent assay (ELISA). Rs9722 was associated with an increased risk of IS (AA vs. GG: adjusted OR = 2.172, 95% CI, 1.175–4.014, P = 0.013; dominant: adjusted OR = 1.507, 95% CI, 1.071–2.123, P = 0.019; recessive: adjusted OR = 1.846, 95% CI, 1.025–3.323, P = 0.041; additive: adjusted OR=1.371, 95% CI, 1.109-1.694, P = 0.003). The A-C-C-C-A haplotype was associated with an increased risk of IS (OR = 1.325, 95% CI, 1.035–1.696, P = 0.025). In addition, individuals carrying the rs9722 GA/AA genotypes had a higher serum S100B compared with the rs9722 GG genotype in IS patients (P = 0.018). Our results suggest that the S100B gene rs9722 polymorphism may contribute to the susceptibility of IS, probably by promoting the expression of serum S100B.