Children’s hospital uses genetic testing for targeted therapies
Scientists and clinicians at Children's Hospital Los Angeles in California have developed a comprehensive genetic testing panel to detect genetic markers that respond to target therapies, according to new research published in the New England Journal of Medicine.
Personalized medicine has expanded its capabilities as technology has grown. Scientists are now using a technology called metagenomic next-generation sequencing (mNGS) to rapidly test clinical samples. This powerful assay can quickly compare unknown genetic material from a patient sample against thousands of known pathogen genomes, researchers say.
The study showed that agnostic testing could lead to treatments for infections that were not identified using standard testing methods. More than 200 patients at eight hospitals were enrolled in this year-long study. Cerebrospinal fluid was sampled from patients who presented with meningitis- or encephalitis-like symptoms. Samples were then analyzed using either standard laboratory testing or mNGS. Out of 58 total diagnoses, sequencing identified 13 infections, more than 20 percent, that were not detected in standard clinical testing.
Now that science has the capability to sequence and compare genomes, it is becoming clear that genomic testing can, and should be, used to identify infectious pathogens, according to Jennifer Dien Bard, PhD, director of the clinical microbiology and virology laboratory and lead author of the study. This is especially important in diseases that could stem from multiple potential causes. For example, meningitis and encephalitis are serious central nervous system conditions that often arise from infection. Proper and timely diagnoses of these infections are critical so that patients can receive treatments before complications develop.
Many types of pathogens, bacteria, viruses, fungi, and parasites, can cause meningitis and encephalitis, making targeted testing difficult. Though laboratories can test samples for a handful of possible culprits, there is a limit to the number of pathogens they can test for at one time. Negative results can delay treatments and leave doctors, patients, and families searching for answers.
Clinicians nationwide are showing that broader genetic testing can deliver answers that standard laboratory tests fail to provide. Instead of one particular target, mNGS testing quickly compares sample genetic material to thousands of targets.
Dien Bard said she envisions a future in which these agnostic, genomic assays are integrated into routine clinical care.
"The trial showed just how sequencing technology can really have a positive clinical impact on patients. In just this study alone, thirteen infections were diagnosed solely because of this technology," she said in a statement. "That's thirteen additional families who got answers."