Could PBMC Gene Expression Signatures Be Used for Predicting Response to Therapy?
Weinstock-Guttman et al.  analyzed the acute transcriptional response of 4,000 genes in peripheral blood lymphocytes to IFNβ. They identified increases in known interferon-inducible genes, and in genes involved in antiviral activity and interferon signaling. Using complementary DNA (cDNA) arrays, Sturzebecher et al.  identified gene expression signatures that distinguished IFNβ responders from nonresponders. And now, in a new study published in last month’s PLoS Biology, Baranzini et al.  provide compelling evidence that these PBMC gene expression signatures can be used to predict response to therapy (Figure 1). They studied the expression of 70 genes selected for their presumed biological function in 52 patients with MS, followed up for at least two years after initiation of IFNβ therapy. Instead of using microarrays that carry probes for thousands of genes, they chose to use real-time PCR. This method is highly sensitive, specific, and reproducible across different labora