Scientists have tried unsuccessfully for years to identify a single marker or a suite of markers that could diagnose infection in ICUs. While both fever and an elevated white blood cell count often indicate an infection in healthy individuals, the same symptoms are widespread in ICU patients, where they are linked to a range of underlying conditions, including trauma, shock, organ failure and surgical complications. Diagnosis of infection is even more complicated in patients on a ventilator because they are sedated and the breathing tube prevents them from talking.
The current study took Cobb and his Washington University colleagues from the laboratory bench to patients' bedsides as they refined their method to diagnose pneumonia. Initially, they used the gene chip technology in mice to identify 219 genes whose patterns of expression could distinguish pneumonia from widespread inflammation, another common condition in intensive care units that involves systemic activation of the immune system. The patterns of gene expression in mice also could differentiate between gram-negative bacteria (Pseudomonas), a common type responsible for ventilator-associated pneumonia, and gram-positive bacteria (Streptococcus), which is a frequent cause of pneumonia in a community setting.
The researchers then moved to the ICU to determine whether the activity of the equ
|Contact: Caroline Arbanas|
Washington University in St. Louis