Introduction: stroke diagnosis is not always easy. Many non-vascular medical and neurological problems can mimic stroke, featuring focal neurological signs and symptoms of sudden onset. These patients can potentially be harmed by stroke-specific treatments, including fibrinolysis. Hence, a test capable of unveiling stroke mimics would be useful.
Hypothesis: A proteomic platform called immunosignaturing may be useful to distinguish between acute ischemic stroke and imitators.
Methods: plasma samples from 12 patients brought to the ER because of a stroke code were analyzed: 6 were diagnosed with acute ischemic stroke and 6 with seizures mimicking a stroke. Additional 12 samples from healthy volunteers were used as controls. Immunosignatures use microarrays with 10,000 random sequence peptides, which behave as antibody mimotopes. Antibody binding to microarray peptides is detected with secondary antibodies labeled with fluorescent dyes, then scanned with a laser. Resulting profiles are unique to each individual. Samples were run in duplicates, with good correlation between replicates, high signal and low background. Mann-Whitney U-test and Fisher‘s exact test were used to compare groups.
Results: samples were obtained within 130 minutes after symptoms onset. We found no differences between groups related to age, gender, or cardiovascular risk factors. Analysis of signature profiles revealed striking separation between stroke and seizure cases. The Figure depicts a heatmap comparing the stroke (yellow bar underneath) and seizure patients. Peptides with QADAP or QADLP motifs helped differentiate the groups.
Conclusions: We describe the first application of an antibody-profiling platform called immunosignaturing to the study of ischemic stroke and its imitators. Despite the small sample, these very preliminary results suggest that antibody signatures may help distinguish acute ischemic strokes from other conditions, deserving future research.