Duke Health researchers have made a significant discovery regarding the persistent pain experienced by individuals with recurring urinary tract infections (UTIs) even after antibiotic treatment. In a paper published in Science Immunology, they identified the root cause as an overgrowth of nerve cells in the bladder. This breakthrough offers a promising new approach to managing UTI symptoms by targeting the underlying issue more effectively, potentially reducing unnecessary antibiotic use.
According to senior author Soman Abraham, Ph.D., “Urinary tract infections account for almost 25% of infections in women. Many are recurrent UTIs, with patients frequently complaining of chronic pelvic pain and urinary frequency, even after a round of antibiotics. Our study, for the first time, describes an underlying cause and identifies a potential new treatment strategy.”
By analyzing bladder biopsies from UTI patients experiencing pain without detectable bacteria in their urine, researchers found heightened activation of sensory nerves compared to non-UTI individuals. Further investigations in mice revealed the underlying events, with unique conditions in the bladder that prompt activated nerves in the lining to bloom and grow with each infection.
“Typically, during every bout of UTI, epithelial cells laden with bacteria are sloughed off, and significant destruction of nearby nerve tissue occurs,” said Byron Hayes, lead author of the study. “These events trigger a rapid repair program in the damaged bladder involving massive regrowth of destroyed nerve cells.”
The study revealed that mast cells play a crucial role in this process by releasing nerve growth factors that promote nerve overgrowth and increased sensitivity, resulting in pain and urgency. By inhibiting the production of these nerve growth factors in study mice, researchers successfully alleviated these symptoms.
“This work helps illuminate a puzzling clinical condition that drives medical costs and affects the quality of life of millions of people, primarily women,” Abraham said. “Understanding the crosstalk between mast cells and nerves is an essential step toward effective treatments for people suffering repeat urinary tract infections.”