Blog | Friday, September 2, 2011

QD: News Every Day--Some people can't get sick from the flu

Some people's genomes shrug off flu infections, reported engineers who turned satellite imaging algorithms inward to the human body.

One of the tools for the research was a mathematical method previously used for satellite imaging of the environment. It's a pattern-recognition tool called Bayes Linear Unmixing, which researchers applied to genomics with nearly no modification, according to a University of Michigan press release.

Researchers compared the genomic responses of 17 healthy participants inoculated with live influenza (H3N2/Wisconsin), and collected 22,000 genes from 267 blood samples taken at 16 time points over 5.5 days. They used the pattern-recognition tool to look at gene expression. Results appeared online at PLoS Genetics Aug. 25.

About half the people showed symptoms and half did not. Viral sensing and inflammation in symptomatic hosts clearly correlated to clinical symptom development over time, the researchers wrote.

Asymptomatic patients presented "dramatic transcriptional responses" to inoculation. More than 3,000 genes expressed themselves differently after infection. Two subjects who never yielded detectable virus levels (less than 1.25 TCID50/mL) appeared to have the most significant suppression.

The inflammatory genomic signature that differentiated those who got sick from those who did could be measured up to about 36 hours before peak flu symptoms developed, which may someday allow for earlier detection, earlier precautions and prevention of the worst symptoms, the researchers said.