Infectious disease specialists are using "fingerprints" that pathogens leave behind on immune system cells to identify common acute infections in children. Pathogens activate very specific genes that code for receptors in leukocytes. When researchers examine the leukocytes, they can see a pattern of receptors specific to a specific pathogen. Akin to a fingerprint, this pattern provides reliable disease identification.

In a study, researchers analyzed gene expression patterns in leukocytes from 29 children known to have one of four common infections: influenza A, Staphylococcus aureus, Streptococcus pneumoniae, or Escherichia coli. Using gene expression profiling, they distinguished between the influenza, E. coli, and strep infections in 95% of cases. They could also distinguish E. coli from staph infections with 85% accuracy and found a clear distinction between viral and bacterial pneumonias.

Researchers say their next step will be to see if gene expression profiling can work in a challenging clinical setting, such as a hospital emergency department.

Source: Ramilo O, et al., Gene expression patterns in blood leukocytes discriminate patients with acute infections, Blood, March 1, 2007.