Aim: Increased levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, have been observed in patients with cardiovascular risk factors and atherosclerosis and in patients with a history of stroke. The role of ADMA and its analogue symmetric dimethylarginine (SDMA) in acute ischemic stroke is yet unclear. We hypothesized that plasma dimethylarginine levels increase in the hyper-acute phase after ischemic stroke and that their time course is related to stroke outcome. Methods: Plasma dimethylarginines ADMA and SDMA and L-arginine levels were measured in 67 patients at 6, 12, 24 hours, as well as 3 and 7 days after stroke onset using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS). Data were compared to control data from 32 age-adjusted healthy volunteers. Clinical outcome was assessed using the modified Rankin Scale (mRS) at 90 days after stroke. Results: At baseline, plasma ADMA levels were higher in stroke patients than in controls, whereas plasma SDMA and L-arginine levels did not differ from control subjects. The time courses of ADMA and SDMA were related to the clinical outcome. Binary logistic regression analysis showed that ADMA levels of ≥ 0.566 mol/L at day 3, ≥ 0.530 mol/L at day 7 and SDMA levels of ≥ 0.59 mol/L at 24 hours predicted an unfavorable clinical outcome. Conclusions: An increase of both ADMA and SDMA plasma levels within the first 72 hours after the onset of ischemic stroke predicts a poor outcome. J Atheroscler Thromb, 2011; 18:753-761.

Interferon-beta (IFN-beta) reduces disease activity in a subgroup of patients with relapsing remitting multiple sclerosis (MS). The mechanism of action as well as the pathophysiological basis of responsiveness to IFN-beta is not well understood. Since T-cell activation plays an important part in the pathophysiology of MS, we here investigated the effect of IFN-beta on the expression of co-signaling pathways (CD28-CD80/CD86, CD154-CD40, ICOS-ICOSL, PD-1-PD-L1/2) in MS patients and correlated the results with the clinical response to IFN-beta in individual patients. Expression of co-signaling molecules was measured by flow cytometry in vitro on peripheral blood mononuclear cells after incubation with IFN-beta, and in vivo in whole blood samples of 32 untreated and 24 IFN-beta treated MS patients, including 13 patients longitudinal. IFN-beta treatment induced upregulation of CD40, CD80, CD86, PD-L1 and PD-L2 on monocytes as well as PD-L1 on CD4+-T-cells in vitro and in vivo. IFN-beta treated MS patients were grouped into responders and non-responders on the basis of Kurtzkés EDSS (expanded disability status scale) progression and relapse rate. Upregulation of CD40, CD86 and PD-L2 on monocytes was associated with treatment response to IFN-beta (P < 0.001, P = 0.028 and P = 0.028, respectively). Our results show that IFN-beta upregulates co-stimulatory as well as co-inhibitory molecules in vitro and in vivo implicating that modulation of the balance between positive and negative co-stimulatory signals might be an important part of the mechanism of action of IFN-beta in MS. Upregulation of the expression of CD40, CD86 and PD-L2 may be useful as a predictive marker for clinical response to IFN-beta treatment at early timepoints during IFN-beta therapy.

Background and Purpose-Knowledge about cytotoxic edema (CE) in intracerebral hemorrhage is still limited. We aimed to analyze its presence, temporal pattern, and prognostic meaning. Methods-Twenty-one patients with primary intracerebral hemorrhage underwent magnetic resonance imaging at days 1, 3, and 7 after symptom onset. CE was identified using diffusion-weighted imaging. Hematoma and perihematomal edema volumes were measured on fluid-attenuated inversion recovery images. National Institutes of Health Stroke Scale score was assessed at admission and with each magnetic resonance imaging. Clinical outcome was assessed by modified Rankin scale at 90 days. Results-CE appeared in half of the patients within the first 24 hours. The apparent diffusion coefficient values decreased until day 3 and were significantly reversed from days 3 through 7 (P<0.01). Patients with CE showed significantly faster perihematomal edema growth from day 0 to 1 (P=0.036) than those without. Larger 3-day perihematomal edema volume (P=0.02) and presence of CE on day 3 (P=0.07) were associated with poor clinical outcome. Conclusions-CE is associated with stroke severity, perihematomal edema volume, and poor outcome. It is considered to indicate ongoing neuronal injury and, thus, might emerge as new treatment target. (Stroke. 2013;44:1144-1146.)

BackgroundElevated levels of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are accompanied by endothelial dysfunction and predict adverse outcome after ischemic stroke. Via induction of oxidative stress, dimethylarginines are possibly linked to the inflammatory cascade after stroke that is known to considerably contribute to secondary progression of brain injury. We sought to investigate the association between dimethylarginines and inflammatory mediators in patients with acute ischemic stroke.MethodsPlasma levels of ADMA and SDMA were measured in prospectively collected blood samples of 58 patients with acute ischemic stroke. Blood samples were taken at 6 hours, 12 hours, 24 hours, 3 days and 7 days after onset of symptoms. Analyses of ADMA and SDMA were done by high-performance liquid chromatography-tandem mass spectrometry. Monocyte chemotactic protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), interleukin-6 (IL-6), C-reactive protein (CRP) and S100B as markers of inflammation and brain damage were determined by commercially available immunometric assays. Patient data were compared with control data from 32 age-adjusted healthy volunteers. Baseline stroke severity was evaluated by the National Institutes of Health Stroke Scale (NIHSS) (NIHSS 0 to 1: mild stroke; NIHSS 2 to 8: moderate stroke; NIHSS ≥9: severe stroke).ResultsPlasma ADMA and SDMA levels significantly correlated with blood levels of inflammatory mediators up to day 7 after stroke. On multiple stepwise linear regression analysis ADMA correlated with TIMP-1 at 6 hours, 24 hours, 3 days and 7 days, MMP-9 at 12 hours and IL-6 at 7 days (P <0.05) while SDMA correlated with MCP-1 at 6 hours, 24 hours, 3 days and 7 days as well as IL-6 at 3 days and 7 days (P <0.05).ConclusionsThe levels of the vasoactive compound ADMA as well as levels of its structural isomer SDMA are associated with levels of inflammatory mediators after acute ischemic stroke. Further studies need to elucidate the cause and effect relationship of these crucial players.

Infections after ischemic stroke are known to complicate the clinical course and worsen the outcome. Neuroinflammation is one of the predominant mechanisms of secondary progression of brain injury and infection and is far from being well understood. Experimental data demonstrate that ischemic stroke patients are at a higher risk for systemic infections if they show a pronounced anti-inflammatory response after the event, which is considered an indication of a stress-mediated reduction of immune competence. Only a small number of studies describe the time course of inflammation mediators after ischemic stroke in patients with early poststroke infections. Levels of inflammation mediators after the event of stroke differ, depending on clinical severity and concomitant infectious diseases. Thus, sequential dynamics of early inflammation must be considered in the development of both mechanism-targeting anti-inflammatory and anti-infectious treatment strategies in ischemic brain damage.