Host Protein Bio-Array Distinguishing Bacterial and Non-Bacterial Sources Provides Similar Diagnostics in Immunosuppressed Patients Presenting to the ED with Sepsis

Abstract

Background

Immunosuppressed (ISD) patients presenting to emergency departments (EDs) with sepsis concerns of unknown etiology require a broad work-up. A rapid immunoassay (MeMedBV©, (BV)) which measures TNF-related apoptosis-inducing ligand (TRAIL), interferon gamma-induced protein 10 (IP-10), C-reactive protein (CRP), and a proprietary ‘BV score’ are used to distinguish sepsis source (bacterial versus non-bacterial) but is unclear whether it is useful in ISD patients.

Methods

A case-controlled series comparing the diagnostic response of MeMedBV© on ISD subjects presenting with sepsis physiology. A definitive diagnosis of bacterial or non-bacterial infection was adjudicated through blood cultures, laboratory, and radiography. The BV scores and individual protein levels were tabulated for all ISD and immunocompetent (ICT) subjects. Comparison analysis using the non-parametric Kruskal-Wallis test assessed diagnostic accuracy between the ISD and ICT groups. The null hypothesis was that the BV and host protein scores are similar in the ISD compared to the ICT group in patients presenting with sepsis.

Results

For patients with bacterial etiology (n=13), the BV score comparison between ISD and ICT resulted in an H-statistic of 0.95 with a p-value of 0.33, TRAIL: H-statistic; 3.17, p-value 0.07, CRP: H-statistic; 1.84, p-value 0.17, and IP-10: H-statistic; 3.23, p-value of 0.07. In the non-bacterial group (n=6), the BV score comparison resulted in an H-statistic; 0.03, p-value of 0.87, TRAIL: H-statistic; 0.01, p-value 0.94, CRP: H-statistic; 0.24, p-value 0.62, and IP-10: H-statistic; 0.11, p-value 0.74. Thus, no significant differences of BV scores or host proteins were reported between ISD and ICT groups.

Conclusion

This host 3-protein bio-array and BV score performed similarly in both immunosuppressed and immunocompetent groups. A rapid diagnostic test measuring host protein response may therefore be useful in distinguishing bacterial and non-bacterial sources of infection despite ISD status. Further studies with larger sample sizes and various causes of ISD are recommended to refine diagnostic performance in clinical settings.