The correlation of TWEAK level and with involved area on MRI in stroke. Muhittin Serkan Yilmaz, Murat Yilmaz, Bahattin Isik, Cihat Yel, Cemil Kavalci * , Burak Demirci, Selim Inan, Rasime Pelin Kavak, İlhan Balamir, Turan Turhan Department of Emergency, Faculty of Medicine, Baskent University, Ankara, Turkey Abstract The aim of this study was to value of TWEAK protein in stroke diagnosis and the correlation between Tweak level and lesion size on diffusion MRI in patients admitted to emergency department for acute stroke. Our study was prospectively conducted in a group of patients diagnosed with stroke in the emergency department and a control group between 1 June 2014 and 31 August 2014. Age, sex, vital parameters, comorbid conditions, neurological deficit level, Tweak level, and involved volume on D-MRI were analyzed. Age, sex, vital parameters, comorbid conditions, and Tweak levels were compared between the patient and control groups. Tweak level was compared with neurological deficit and diffusion on D-MRI imaging in the patient group. The results were evaluated in a confidence interval of 95% and at a significance level of p<0.05. There were no significant differences between both groups with respect to age and sex distribution. The median Tweak level of the patient group was significantly higher (912.1 pg/ml vs 808.3 pg/ml, p<0.05). In the patient group NIHSS score had a positive correlation to MRI lesion size (p<0.05) but not to Tweak level (p>0.05). There was no correlation between Tweak level and the involved area on diffusion MRI (p>0.05).In conclusion, Tweak appears as a parameter that can be used in patients with a clinical presentation consistent with Stroke. It can be used for diagnostic purposes when cranial CT does not support the diagnosis or for supporting diagnosis when D-MRI is not available. Keywords: Emergency, Stroke, Tweak. Accepted on July 21, 2016 Introduction Stroke is the third leading cause of mortality and the top leading cause of morbidity worldwide [1]. While 85% of cases are of the ischemic type that develop secondary to thromboembolism, 15% of cases are of the hemorrhagic type, with the hypertensive form being the most common [1,2]. Early reperfusion of ischemic brain areas provide significant reductions in mortality and morbidity [3,4]. In emergency care setting, the diagnosis of stroke is made by patient history, physical examination, and imaging studies by Computerized Tomography (CT), and/or diffusion magnetic resonance imaging (D-MRI) [1]. Lack of widespread availability and requirement of experienced teams limit the use of these imaging modalities [5]. Recently, studies on ischemia (cardiac, intracerebral) have begun to investigate biomarkers that show variability especially in the physiopathology of ischemic events and at the post-ischemia period. Based on these studies, the idea has been born that cytokines playing a role in ischemic process may be used for diagnostic and therapeutic purposes [5-7]. Tumor necrosis factor-like weak inducer of apoptosis (Tweak) is thought to be one of those markers [8,9]. Tweak is a transmembrane protein (type 2) that is a member of tumor necrosis factor (TNF) super family [10]. Its presence has been demonstrated in heart [11], brain [12], kidney [13], and blood cells [14]. It functions in cellular growth stimulation, cell growth, and apoptosis [15,16]. Tweak/Fn14 has been reported to exist mainly in endothelial cells, perivascular astrocytes, microglia, and neurons of the central nervous system [15]. TWEAK stimulates various cellular responses including proliferation, survival, apoptosis, migration, and differentiation and plays major role in neuroinflammation, [17,18]. Inta et al. showed that expression of TWEAK increase in the acute ischemic stroke patients [19]. In our study it was aimed to value of TWEAK protein in stroke diagnosis and explores the correlation between Tweak level and size of lesion on diffusion MRI imaging in patients presenting to Emergency Department (ED) with a clinical consistent stroke symptoms. Materials and Method This prospective case control study was approved by Ankara Numune Training and Research Hospital (3 rd level stroke center) ethics committee (845/2014) and conducted prospectively between 1 June 2014 and 31 August 2014. Patients or patient relatives gave consent for the participation in the study. The inclusion criteria were as follows: having Stroke confirmed by D-MRI (Group P, n=44), healthy volunteer (Group C, n=44), being older than 18 years, giving ISSN 0970-938X www.biomedres.info Biomed Res- India 2017 Volume 28 Issue 3 1110 Biomedical Research 2017; 28 (3): 1110-1114