Abstract: Objective To explore the differential expression of low molecular weight proteins in serum of ischemic stroke patients.Methods Serum samples obtained from ischemic stroke patients (n=33) and normal controls (n=39) were analyzed by Matrix Assisted Laser Desorption/ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS). The severity of stroke was assessed with the National Institutes of Health Stroke Scale (NIHSS) and functional outcome was assessed with modified Rankin Scale (mRS). Results 55 peaks were significantly different between ischemic stroke patients and the controls (P<0.05). There were 7 peaks between 1000~2000 Da, 4 increased peaks and 3 induced peaks in serum of ischemic stroke patients. One induced peak at 1864(m/z) had highest peak intensity in controls and induced significantly in ischemic stroke patients. While induce degree of this peak didn't correlate with the NIHSS, mRS, stroke risk factors and laboratory data. Conclusion The application of this potential biomarker is not restricted to certain subgroups of ischemic stroke patients,so it may serve as one reverse direction biomarker and provide support for early diagnosis and treatment of ischemic stroke.

Key words: ischemic stroke, Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry, biomarker