Translational Stroke Research

, Volume 10, Issue 1, pp 26–35 | Cite as

Shifts in Leukocyte Counts Drive the Differential Expression of Transcriptional Stroke Biomarkers in Whole Blood

  • Grant C. O’Connell
  • Madison B. Treadway
  • Connie S. Tennant
  • Noelle Lucke-Wold
  • Paul D. Chantler
  • Taura L. Barr
Original Article


Our group recently identified a panel of ten genes whose RNA expression levels in whole blood have utility for detection of stroke. The purpose of this study was to determine the mechanisms by which these genes become differentially expressed during stroke pathology. First, we assessed the transcriptional distribution of the ten genes across the peripheral immune system by measuring their expression levels on isolated neutrophils, monocytes, B-lymphocytes, CD-4+ T-lymphocytes, CD-8+ T-lymphocytes, and NK-cells generated from the blood of healthy donors (n = 3). Then, we examined the relationship between the whole-blood expression levels of the ten genes and white blood cell counts in a cohort of acute ischemic stroke patients (n = 36) and acute stroke mimics (n = 15) recruited at emergency department admission. All ten genes displayed strong patterns of lineage-specific expression in our analysis of isolated leukocytes, and their whole-blood expression levels were correlated with white blood cell differential across the total patient population, suggesting that many of them are likely differentially expressed in whole blood during stroke as an artifact of stroke-induced shifts in leukocyte counts. Specifically, factor analysis inferred that over 50% of the collective variance in their whole-blood expression levels across the patient population was driven by underlying variance in white blood cell counts alone. However, the cumulative expression levels of the ten genes displayed a superior ability to discriminate between stroke patients and stroke mimics relative to white blood cell differential, suggesting that additional less prominent factors influence their expression levels which add to their diagnostic utility. These findings not only provide insight regarding this particular panel of ten genes, but also into the results of prior stroke transcriptomics studies performed in whole blood.


Triage Microarray RNA sequencing CBC Complete blood count PCR NLR Neutrophil-lymphocyte ratio MLR Monocyte-lymphocyte ratio 



The authors would foremost like to thank the subjects and their families, as this work was truly made possible by their selfless contribution. In addition, we would like to thank the stroke team at Ruby Memorial Hospital for supporting this research effort.


Work was funded via a Robert Wood Johnson Foundation Nurse Faculty Scholar award to TLB (70319), a National Institutes of Health CoBRE sub-award to TLB (P20 GM109098), and Case Western Reserve University FPB School of Nursing start-up funds issued to GCO.

Compliance with Ethical Standards

Procedures were approved by the institutional review boards of West Virginia University and Ruby Memorial Hospital (IRB protocol 1410450461R001), and written informed consent was obtained from all subjects or their authorized representatives prior to study procedures.

Conflict of Interest

GCO and TLB have a patent pending re: genomic patterns of expression for stroke diagnosis. TLB serves as chief scientific officer for Valtari Bio Incorporated. Work by GCO is part of a pending licensing agreement with Valtari Bio Incorporated. GCO has received consulting fees from Valtari Bio Incorporated. The remaining authors report no potential conflicts of interest.

Supplementary material

12975_2018_623_MOESM1_ESM.pdf (1.6 mb)
ESM 1 (PDF 1655 kb)


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Grant C. O’Connell
    • 1
  • Madison B. Treadway
    • 2
  • Connie S. Tennant
    • 3
  • Noelle Lucke-Wold
    • 3
  • Paul D. Chantler
    • 4
    • 5
  • Taura L. Barr
    • 6
  1. 1.School of NursingCase Western Reserve UniversityClevelandUSA
  2. 2.Department of Biology, Eberly College of Arts and SciencesWest Virginia UniversityMorgantownUSA
  3. 3.Center for Basic and Translational Stroke Research, Robert C. Byrd Health Sciences CenterWest Virginia UniversityMorgantownUSA
  4. 4.Center for Cardiovascular and Respiratory Sciences, Robert C. Byrd Health Sciences CenterWest Virginia UniversityMorgantownUSA
  5. 5.Division of Exercise Physiology, School of MedicineWest Virginia UniversityMorgantownUSA
  6. 6.Valtari Bio IncorporatedMorgantownUSA

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