Research forum abstractPoster session: Diagnosis/treatment106 Neuronal Biomarkers May Require Age-Adjusted Norms
Section snippets
Study Objectives
Neuronal biomarkers have been shown to reflect neuronal injury, and may serve as diagnostic tools for traumatic brain injury (TBI). Two of these are glial fibrillary acidic protein (GFAP) and Ubiquitin C-terminal hydrolase (UCH-L1). There is data supporting increased expression of GFAP in the astrocytes of older patients, but no data exist on whether serum values for these biomarkers increase with aging. The usefulness of these biomarkers to diagnose TBI will depend on accurate information of
Methods
Setting: Two large urban emergency departments. Design: Prospective observational study. Participants: We compared GFAP and UCH-L1 levels (UCH-L1, GFAP) in healthy “control” patients ranging in age from 18 to 91. We enrolled a total of 95 subjects, 31 of whom were 65 years of age or older. All control subjects had no antecedent trauma, and no history of diabetes, neurodegenerative disease, or stroke. Protocol: A single blood draw of 5 milliliters was performed following informed consent. Serum
Results
Median serum levels (ng/ml) for GFAP were 0.15 in subjects ≥ 65 years vs 0.01 in those younger than 65 years (p=0.004). UCH-L1 levels in subjects ≥ 65 years were 0.11 vs 0.13 in younger subjects (p=0.18). The Kruskal Wallis test did not show a significant difference in serum GFAP when measured across all 3 groups, although there was a trend toward significance (p=.07). There was a significant age related difference in UCH-L1 between the youngest and middle age group (0.10 vs 0.15; p=0.012).
Conclusion
Serum GFAP and UCH-L1 values may be normally increased in older subjects without TBI. Age-adjusted normative data may be important in interpreting these values in older adults when trying to diagnose TBI.