title: Diagnostic potential of the NMDA receptor peptide assay for acute ischemic stroke.
abstract: BACKGROUND
  The acute assessment of patients with suspected ischemic stroke remains challenging. The use of brain biomarker assays may improve the early diagnosis of ischemic stroke. The main goal of the study was to evaluate whether the NR2 peptide, a product of the proteolytic degradation of N-methyl-D-aspartate (NMDA) receptors, can differentiate acute ischemic stroke (IS) from stroke mimics and persons with vascular risk factors/healthy controls. A possible correlation between biomarker values and lesion sizes was investigated as the secondary objective.
  
  
  RESULTS
  A total of 192 patients with suspected stroke who presented within 72 h of symptom onset were prospectively enrolled. The final diagnosis was determined based on clinical observations and radiological findings. Additionally gender- and age-matched healthy controls (n = 52) and persons with controlled vascular risk factors (n = 48) were recruited to compare NR2 peptide levels. Blinded plasma was assayed by rapid magnetic particles (MP) ELISA for NR2 peptide within 30 min and results for different groups compared using univariate and multivariate statistical analyses. There was a clinical diagnosis of IS in 101 of 192 (53%) and non-stroke in 91 (47%) subjects. The non-stroke group included presented with acute stroke symptoms who had no stroke (n = 71) and stroke mimics (n = 20). The highest NR2 peptide elevations where found in patients with IS that peaked at 12 h following symptom onset. When the biomarker cut off was set at 1.0 ug/L, this resulted in a sensitivity of 92% and a specificity of 96% to detect IS. A moderate correlation (r(s) = 0.73) between NR2 peptide values and acute ischemic cortical lesions (<200 mL) was found.
  
  
  CONCLUSIONS
  This study suggests that the NR2 peptide may be a brain specific biomarker to diagnose acute IS and may allow the differentiation of IS from stroke mimics and controls. Additional larger scale clinical validation studies are required.
authors: WellStar College of Health and Human Services, Kennesaw State University, Kennesaw, Georgia, United States of America. sdambino@kennesaw.edu
authors: Svetlana A
authors: SA
authors: Dambinova
authors: Kerstin
authors: K
authors: Bettermann
authors: Theodore
authors: T
authors: Glynn
authors: Matthew
authors: M
authors: Tews
authors: David
authors: D
authors: Olson
authors: Joseph D
authors: JD
authors: Weissman
authors: Richard L
authors: RL
authors: Sowell
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000150:complications*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D016194:Receptors, N-Methyl-D-Aspartate / Q000737:chemistry*; D020521:Stroke / Q000097:blood* / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D016194:Receptors, N-Methyl-D-Aspartate