DNA Test Predicts Infections in Kids
Researchers at St. Jude Children's Research Hospital have found a promising new way to detect bloodstream infections in children with leukemia. A new study shows that sequencing microbial cell-free DNA can predict infections days before they become clinically apparent, offering a critical early warning.
The new test, called plasma microbial cell-free DNA sequencing (mcfDNA-Seq), was able to predict bloodstream infections in just over half of the cases up to three days before symptoms appeared. The study, led by Dr. Joshua Wolf of the St. Jude Department of Host-Microbe Interactions, was published in *The Lancet Microbe*. Researchers analyzed plasma samples collected daily from 158 pediatric patients with high-risk leukemia. This method detects fragments of microbial DNA that are circulating in the blood, allowing for the identification of infection-causing pathogens before traditional blood cultures can. Bloodstream infections are a significant danger for children undergoing leukemia treatment, as their immune systems are weakened by chemotherapy. These infections can rapidly lead to severe complications like sepsis, which can delay or disrupt cancer treatment and, in some instances, be fatal. Currently, there is no reliable way for doctors to predict these infections before a child shows clinical symptoms. The standard method of blood cultures often fails to provide early detection. The mcfDNA-Seq test accurately ruled out infection in 93.8% of samples from uninfected or healthy patients. This research is a step towards what Dr. Wolf calls a "'crystal ball' to help identify patients who are about to get sick." The ability to predict an infection days in advance could allow for preemptive treatment, potentially preventing children from becoming ill and keeping their cancer therapy on track. Children with hematologic cancers like leukemia are at a greater risk for healthcare-associated bloodstream infections compared to those with solid tumors. These infections are a major cause of complications and mortality in pediatric cancer patients. The mortality odds for patients with such an infection are nearly seven times higher than for those without. Gram-negative bacteria are a major cause of these bloodstream infections in children with leukemia and are associated with severe neutropenia and high mortality rates. Some studies show that Gram-negative bacteria are the leading pathogens in these cases.
