Recurrent infections drive persistent bladder dysfunction and pain via sensory nerve sprouting and mast cell activity.

Urinary tract infections (UTIs) account for almost 25% of infections in women. Many are recurrent (rUTI), with patients frequently experiencing chronic pelvic pain and urinary frequency despite clearance of bacteriuria after antibiotics. To elucidate the basis for these bacteria-independent bladder symptoms, we examined the bladders of patients with rUTI. We noticed a notable increase in neuropeptide content in the lamina propria and indications of enhanced nociceptive activity. In mice subjected to rUTI, we observed sensory nerve sprouting that was associated with nerve growth factor (NGF) produced by recruited monocytes and tissue-resident mast cells. Treatment of rUTI mice with an NGF-neutralizing antibody prevented sprouting and alleviated pelvic sensitivity, whereas instillation of native NGF into naïve mice bladders mimicked nerve sprouting and pain behavior. Nerve activation, pain, and urinary frequency were each linked to the presence of proximal mast cells, because mast cell deficiency or treatment with antagonists against receptors of several direct or indirect mast cell products was each effective therapeutically. Thus, our findings suggest that NGF-driven sensory sprouting in the bladder coupled with chronic mast cell activation represents an underlying mechanism driving bacteria-independent pain and voiding defects experienced by patients with rUTI.

Science immunology. 2024 Mar 01 [Epub]

Byron W Hayes, Hae Woong Choi, Abhay P S Rathore, Chunjing Bao, Jianling Shi, Yul Huh, Michael W Kim, Andrea Mencarelli, Pradeep Bist, Lai Guan Ng, Changming Shi, Joo Hwan Nho, Aram Kim, Hana Yoon, Donghoon Lim, Johanna L Hannan, J Todd Purves, Francis M Hughes, Ru-Rong Ji, Soman N Abraham

Department of Pathology, Duke University Medical Center, Durham, NC, USA., Division of Life Sciences, Korea University, Seoul 02841, South Korea., Department of Cell Biology, Duke University Medical Center, Durham, NC, USA., Program in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore 169857, Singapore., Singapore Immunology Network, Agency for Science, Technology and Research, Immunos, Biopolis Singapore 138648, Singapore., Shanghai Immune Therapy Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China., Department of Urology, Konkuk University Hospital, Konkuk University School of Medicine, Seoul 05029, South Korea., Department of Urology, Ewha Womans University, College of Medicine, Seoul 07804, South Korea., Department of Urology, Chosun University School of Medicine, Gwangju, South Korea., Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA., Department of Surgery, Division of Urology, Duke University Medical Center, Durham, NC, USA.