EDITOR'S CHOICE IN CLINICAL RESEARCH
A.B. Niculescu et al., “Towards precision medicine for pain: Diagnostic biomarkers and repurposed drugs,” Mol Psychiatr, 24:501–22, 2019.
Patients are often asked by their doctors to rate their pain, most commonly on a scale of 1 to 10. “Pain is a subjective experience,” says physician and professor of psychiatry Alexander Niculescu of Indiana University. “There’s no objective blood test out there.”
He and his colleagues are out to change that. Over the course of a year, the researchers tracked changes in gene expression in three cohorts of patients with major psychiatric disorders, one of which included only patients who had also been diagnosed with pain disorders. Comparing blood samples taken during visits when patients reported experiencing low or high pain, the team identified 60 genes whose RNA levels varied with pain severity. Expression levels of a subset of those genes, the researchers found, successfully predicted pain intensity and future pain-related emergency room visits among some study subjects.
Niculescu’s group suggests that these RNAs could one day serve as biomarkers of pain in a clinical setting, and may even help guide treatment plans. Some of the pain-linked genes the research identified encode protein products that are targets of existing drugs, including medications for pain and psychosis as well as therapies approved for other conditions.
The biomarkers identified may also shed light on the type of pain a patient is experiencing, says Niculescu. Types of pain vary with the patient’s diagnosis, such as depression- or anxiety-related pain, fibromyalgia, or neuropathic pain from damage to the nervous system. Pain is a “complicated, highly individualized, and ever-changing disease state,” says Stanford University psychiatry researcher Monique Smith, who was not involved in the study, in an email to The Scientist.
Utah State University neuroscientist Erin Bobeck, who also did not participate in the research, says that this work is “very timely and very much needed,” but emphasizes that future research should focus on a broader range of patients, not only those with psychiatric disorders.