BackgroundInterleukin-1 (IL-1) is a key mediator of ischaemic brain injury induced by stroke and subarachnoid haemorrhage (SAH). IL-1 receptor antagonist (IL-1Ra) limits brain injury in experimental stroke and reduces plasma inflammatory mediators associated with poor outcome in ischaemic stroke patients. Intravenous (IV) IL-1Ra crosses the blood–brain barrier (BBB) in patients with SAH, to achieve cerebrospinal fluid (CSF) concentrations that are neuroprotective in rats.MethodsA small phase II, double-blind, randomised controlled study was carried out across two UK neurosurgical centres with the aim of recruiting 32 patients. Adult patients with aneurysmal SAH, requiring external ventricular drainage (EVD) within 72 hours of ictus, were eligible. Patients were randomised to receive IL-1Ra (500 mg bolus, then a 10 mg/kg/hr infusion for 24 hours) or placebo. Serial samples of CSF and plasma were taken and analysed for inflammatory mediators, with change in CSF IL-6 between 6 and 24 hours as the primary outcome measure.ResultsSix patients received IL-1Ra and seven received placebo. Concentrations of IL-6 in CSF and plasma were reduced by one standard deviation in the IL-1Ra group compared to the placebo group, between 6 and 24 hours, as predicted by the power calculation. This did not reach statistical significance (P = 0.08 and P = 0.06, respectively), since recruitment did not reach the target figure of 32. No adverse or serious adverse events reported were attributable to IL-1Ra.ConclusionsIL-1Ra appears safe in SAH patients. The concentration of IL-6 was lowered to the degree expected, in both CSF and plasma for patients treated with IL-1Ra.

F o r S t r o k Background and PurposeThe pro-inflammatory cytokine interleukin-1 (IL-1) has a deleterious role in cerebral ischemia, which is attenuated by IL-1 receptor antagonist (IL-1Ra). IL-1 induces peripheral inflammatory mediators, such as interleukin-6 (IL-6), which are associated with worse prognosis after ischemic stroke. We investigated whether subcutaneous (SC) IL-1Ra reduces the peripheral inflammatory response in acute ischemic stroke. MethodsSCIL-STROKE was a single-center, double-blind, randomized, placebo-controlled phase 2 trial of SC IL-1Ra (100mg administered twice daily for three days) in patients presenting within 5h of ischemic stroke onset. Randomization was stratified for baseline NIHSS score and thrombolysis. Measurement of plasma IL-6 and other peripheral inflammatory markers was undertaken at five time points. The primary outcome was difference in concentration of log(IL-6) as area under the curve to Day 3. Secondary outcomes included exploratory effect of IL-1Ra on three month outcome with the modified Rankin Scale (mRS). ResultsWe recruited 80 patients (mean age 72, median NIHSS 12) of whom 73% received intravenous thrombolysis with alteplase. IL-1Ra significantly reduced plasma and plasma C-reactive protein (p<0.001). IL-1Ra was well-tolerated with no safety concerns.Allocation to IL-1Ra was not associated with a favorable outcome on mRS: OR (95% CI) = 0.67 (0.29 to 1.52); p=0.34. Exploratory mediation analysis suggested that IL-1Ra improved clinical outcome by reducing inflammation, but there was a statistically significant, alternative mechanism countering this benefit. ConclusionsIL-1Ra reduced plasma inflammatory markers which are known to be associated with worse clinical outcome in ischemic stroke. SC IL-1Ra is safe and well-tolerated. Further 3

Corticotropin-releasing hormone (CRH) was infused intracerebroventricularly into rats for 7 d via a miniosmotic pump (1 g ⅐ l Ϫ1 ⅐ hr Ϫ1 ). Body temperature and locomotor activity were recorded during the treatment using biotelemetry, whereas hippocampal serotonergic neurotransmission and free corticosterone levels were monitored using in vivo microdialysis on day 7 of CRH treatment. During the microdialysis experiment, behavioral activity was scored by assessing the time during which rats were active (locomotion, grooming, eating, drinking). Continuous intracerebroventricular infusion of CRH produced a transient increase in body temperature and locomotion. Moreover, intracerebroventricularly CRH-treated rats showed elevated free corticosterone levels with no apparent diurnal rhythm.Intraperitoneal administration of bacterial endotoxin [lipopolysaccharide (LPS); 100 g/kg body weight] on day 7 of CRH/ vehicle treatment produced a marked fever response in control animals, which was significantly blunted in intracerebroventricularly CRH-treated rats. Although free corticosterone levels reached similar peak concentrations in both intracerebroventricularly vehicle-and CRH-infused groups after LPS, this response was delayed significantly by ϳ1 hr in the intracerebroventricularly CRH-treated animals. Microdialysis experiments showed no changes in basal extracellular levels of serotonin and 5-hydroxyindoleacetic acid in intracerebroventricularly CRHinfused animals. Injection of LPS in intracerebroventricularly CRHtreated rats produced a blunted 5-HT response and a delayed onset of behavioral inhibition and other signs of sickness behavior. Assessment of the endotoxin-induced cytokine responses showed significantly enhanced plasma interleukin-1 (IL-1) and IL-6 bioactivities in the intracerebroventricularly CRH-infused animals 3 hr after injection of LPS, whereas tumor necrosis factor bioactivity responses were not different.Our data demonstrate that chronically elevated brain CRH levels produce marked changes in basal (largely CRH regulated) physiological and behavioral processes accompanied by aberrant responses to an acute challenge. The present study provides evidence that chronic CRH hypersecretion is an important factor in the etiology of stress-related disorders.