The clinical value of serum tau protein in sepsis-associated encephalopathy

Abstract

Objectives: Sepsis-associated encephalopathy (SAE) is the most widespread metabolic encephalopathy, which continues to be clinically evaluated with the Glasgow Coma Scale (GCS). This study aimed to determine the clinical utility of serum tau protein as an effective and easily attainable biochemical marker of morbidity and mortality for patients with SAE. Methods: This prospective cohort study included 70 patients admitted to the emergency department with sepsis or septic shock, who were then diagnosed with SAE based on the GCS between February 2, 2009 and July 30, 2009. Statistical analyses were performed to investigate the relationship between serum tau levels, the development of SAE and subsequent patient morbidity and mortality. Results Out of the total number of patients enrolled in the study, 50% received the diagnosis of SAE based on GCS upon admission. Of the patients admitted to the hospital for further observation, 2.9% developed SAE over the course of several days using GCS criteria. Even though tau levels were higher in patients with SAE, there was no statistically significant difference with tau levels in patients that did not develop SAE. In addition, there were no significant correlations between tau levels, sequential organ failure assessment (SOFA) score and patient mortality. Conclusions Serum tau levels do not reflect brain damage and encephalopathy for SAE patients. Moreover, this protein does not correlate with patient morbidity and mortality and the SOFA score. Thus, serum tau protein cannot be utilized as a reliable biochemical marker of SAE. Further research is needed to identify effective and easily-obtainable biomarkers to supplement the GCS in SAE diagnosis.