SESSION TYPE: Biomarkers in Respiratory Infections
PRESENTED ON: Monday, October 22, 2012 at 11:15 AM - 12:30 PM
PURPOSE: Serum markers may predict outcomes of patients with bacterial and viral pneumonia, and may serve as therapeutic targets. To our knowledge, there are no case-controlled studies using high throughput analysis to specifically compare pre-illness serum of patients who developed pneumonia to serum from normal individuals. The purpose of our study is to describe the differences in gene expression of modulated proteins in patients with viral and bacterial pneumonia before, during, and after acute illness; and compare these results with healthy individuals.
METHODS: Pre-illness, acute, and convalescent serum samples were collected from military recruits with bacterial or viral pneumonia as confirmed by retrospective review of clinical records and microbiological studies. Fifty patients were included in each group; samples were also collected from 50 healthy volunteers. A panel of 58 proteins were quantified by bead based Luminex technology using less than 100 ul of serum.
RESULTS: Acute bacterial and viral pneumonia were associated with extensive modulation of protein expression; 43% and 60% of examined proteins oscillated significantly in bacterial and viral infections, respectively (p <0.05). Forty eight percent and 49% of the affected proteins had gene expression suppressed at the peak onset of bacterial and viral disease respectively. Pre-illness elevation in fatty acid binding protein, and apolipoprotien A were associated with increased risk of developing bacterial pneumonia while reduction in IL-7 and IL-13 were associated with subsequent development of viral pneumonia. Granulocyte colony stimulator protein elevation was associated with an increased risk of developing both bacterial and viral respiratory infection (p <0.05). Finally, IL-18 elevation differentiated viral from bacterial pneumonia in the acute setting (p <0.05).
CONCLUSIONS: Bacterial and viral-induced pneumonia was associated with extensive oscillation of host gene expression over several weeks. As well, pre-illness protein derangements were associated with increased risk of developing pneumonia.
CLINICAL IMPLICATIONS: This data could be prospectively analyzed to identify patients at higher risk of developing pneumonia and potentially could help identify therapeutic interventions aimed at preventing development of both viral and bacterial infections.
DISCLOSURE: The following authors have nothing to disclose: Russell Miller, James Prahl, J Jonas Carmichael, Gilbert Seda
No Product/Research Disclosure InformationNaval Medical Center San Diego, San Diego, CA