Abstract TP454: Immunological Responses in Patients With Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Pilot Study

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jorge A Roa ◽  
Deepon Sarkar ◽  
Mario Zanaty ◽  
David Hasan ◽  
Edgar Samaniego ◽  
...  

Introduction: Cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) are frequently observed after aneurysmal subarachnoid hemorrhage (aSAH) and contribute to neurocognitive decline and worse outcomes. We hypothesize that aSAH initiates a cascade of neuroinflammatory events which contributes to the development of DCI. Methods: Patients who presented with aSAH requiring external ventricular drainage (EVD) for concomitant hydrocephalus were prospectively enrolled. Cerebrospinal fluid (CSF) samples were collected at different time-points relative to index aSAH injury: acute (days 0-1); pre-vasospasm (days 2-5); vasospasm peak (days 6-9) and post-vasospasm (days 10+). Presence and severity of CVS were assessed using CTA/CTP scans and clinical exam. VEGF and MMP9 (immune affectors) protein levels in the CSF were quantified using ELISA. Mobilization of the immune system was characterized by quantification of innate and adaptive immune cells in the CSF using flow cytometry. Production of inflammatory effector proteins was evaluated using intracellular cytokine staining. Results: Of 13 patients analyzed, 6 (46.2%) experienced CVS. Levels of VEGF and MMP9 were consistently higher in aSAH patients who developed CVS, with the highest difference occurring at the acute phase. Similarly, cellularity analysis revealed elevated counts of monocytes (CD11b + ) in the CSF during the acute phase, with progressive decline at later phases. Microglia (CD45 dim CD11b + ) cells were found to be significantly increased at the post-vasospasm phase. A higher percentage of IFN-γ production cytotoxic T helper cells were found at the acute phase, while the later time points revealed an elevated leveled of CD45RA - CD27 + cytotoxic T cells. Conclusion: Our preliminary data shows an active production of proteins with known immunological functions, mobilization of innate cells, production of inflammatory mediators by adaptive immune cells and altered differentiation status. Our overall goal is to determine if there are potential targets of immunomodulatory therapies which can be used to prevent or treat vasospasms and its related deleterious outcomes.

Author(s):  
Deepti Diwan ◽  
Ananth K. Vellimana ◽  
Diane J. Aum ◽  
Julian Clarke ◽  
James W. Nelson ◽  
...  

Background Many therapies designed to prevent delayed cerebral ischemia (DCI) and improve neurological outcome in aneurysmal subarachnoid hemorrhage (SAH) have failed, likely because of targeting only one element of what has proven to be a multifactorial disease. We previously demonstrated that initiating hypoxic conditioning before SAH (hypoxic preconditioning) provides powerful protection against DCI. Here, we expanded upon these findings to determine whether hypoxic conditioning delivered at clinically relevant time points after SAH (hypoxic postconditioning) provides similarly robust DCI protection. Methods and Results In this study, we found that hypoxic postconditioning (8% O 2 for 2 hours) initiated 3 hours after SAH provides strong protection against cerebral vasospasm, microvessel thrombi, and neurological deficits. By pharmacologic and genetic inhibition of SIRT1 (sirtuin 1) using EX527 and global Sirt1 −/− mice, respectively, we demonstrated that this multifaceted DCI protection is SIRT1 mediated. Moreover, genetic overexpression of SIRT1 using Sirt1‐Tg mice, mimicked the DCI protection afforded by hypoxic postconditioning. Finally, we found that post‐SAH administration of resveratrol attenuated cerebral vasospasm, microvessel thrombi, and neurological deficits, and did so in a SIRT1‐dependent fashion. Conclusions The present study indicates that hypoxic postconditioning provides powerful DCI protection when initiated at clinically relevant time points, and that pharmacologic augmentation of SIRT1 activity after SAH can mimic this beneficial effect. We conclude that conditioning‐based therapies administered after SAH hold translational promise for patients with SAH and warrant further investigation.


Author(s):  
Thea Magrone ◽  
Manrico Magrone ◽  
Matteo Antonio Russo ◽  
Emilio Jirillo

Background: Platelets are cellular fragments derived from bone-marrow megacaryocytes and they are mostly involved in haemostasis and coagulation. However, according to recent data, platelets are able to perform novel immune functions. In fact, they possess a receptorial armamentarium on their membrane for interacting with innate and adaptive immune cells. In addition, platelets also secrete granules which contain cytokines and chemokines for activating and recruiting even distant immune cells. Objectives: The participation of platelets in inflammatory processes will be discussed also in view of their dual role in terms of triggering or resolving inflammation. Involvement of platelets in disease will be illustrated, pointing to their versatile function to either up- or down-regulate pathological mechanisms. Finally, despite the availability of some anti-platelet agents, such as aspirin, dietary manipulation of platelet function is currently investigated. In this regard, special emphasis will be placed on dietary omega-3 polyunsaturated fatty acids (PUFAs) and polyphenol effects on platelets. Conclusion: Platelets play a dual role in inflammatory-immune-mediated diseases either activating or deactivating immune cells. Diet based on substances, such as omega-3 PUFAs and polyphenols, may act as a modulator of platelet function, even if more clinical trials are needed to corroborate such a contention.


2021 ◽  
pp. neurintsurg-2021-017504
Author(s):  
Stefan Wanderer ◽  
Lukas Andereggen ◽  
Jan Mrosek ◽  
Sepide Kashefiolasl ◽  
Gerrit Alexander Schubert ◽  
...  

BackgroundPoor patient outcomes after aneurysmal subarachnoid hemorrhage (SAH) occur due to a multifactorial process, mainly involving cerebral inflammation (CI), delayed cerebral vasospasm (DCVS), and delayed cerebral ischemia, followed by neurodegeneration. CI is mainly triggered by enhanced synthesis of serotonin (5-HT), prostaglandin F2alpha (PGF2a), and cytokines such as interleukins. Levosimendan (LV), a calcium-channel sensitizer, has already displayed anti-inflammatory effects in patients with severe heart failure. Therefore, we wanted to elucidate its potential anti-inflammatory role on the cerebral vasculature after SAH.MethodsExperimental SAH was induced by using an experimental double-hemorrhage model. Sprague Dawley rats were harvested on day 3 and day 5 after the ictus. The basilar artery was used for isometric investigations of the muscular media tone. Vessel segments were either preincubated with LV or without, with precontraction performed with 5-HT or PGF2a followed by application of acetylcholine (ACh) or LV.ResultsAfter preincubation with LV 10−4 M and 5-HT precontraction, ACh triggered a strong vasorelaxation in sham segments (LV 10−4 M, Emax 65%; LV 10−5 M, Emax 48%; no LV, Emax 53%). Interestingly, SAH D3 (LV 10−4, Emax 76%) and D5 (LV 10−4, Emax 79%) segments showed greater vasorelaxation compared with sham. An LV series after PGF2a precontraction showed significantly enhanced relaxation in the sham (P=0.004) and SAH groups (P=0.0008) compared with solvent control vessels.ConclusionsLV application after SAH seems to beneficially influence DCVS by antagonizing 5-HT- and PGF2a-triggered vasoconstriction. Considering this spasmolytic effect, LV might have a role in the treatment of SAH, additionally in selected patients suffering takotsubo cardiomyopathy.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 820
Author(s):  
Keshav Jayaraman ◽  
Meizi Liu ◽  
Gregory J. Zipfel ◽  
Umeshkumar Athiraman

Numerous studies have demonstrated the ability of isoflurane conditioning to provide multifaceted protection against aneurysmal subarachnoid hemorrhage (SAH)-associated delayed cerebral ischemia (DCI); however, preclinical studies have not yet examined whether other commonly used inhalational anesthetics in neurological patients such as sevoflurane or desflurane are also protective against SAH-induced neurovascular deficits. We therefore sought to identify the potential for sevoflurane and desflurane conditioning to protect against DCI in an endovascular perforation mouse model of SAH. Neurological function was assessed daily via neuroscore. Large artery vasospasm and microvessel thrombosis were assessed three days after SAH or sham surgery. Four groups were examined: Sham, SAH + room air, SAH + 2% Sevoflurane, and SAH + 6% Desflurane. For the SAH groups, one hour after surgery, mice received 2% sevoflurane, 6% desflurane, or room air for one hour. We found that conditioning with sevoflurane or desflurane attenuated large artery vasospasm, reduced microvessel thrombosis, and improved neurologic function. Given their frequent clinical use and strong safety profile in patients (including those with SAH), these data strongly support further studies to validate these findings in preclinical and clinical studies and to elucidate the mechanisms by which these agents might be acting.


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