(267) The Prevalence of Conditions Involving Aberrant Mast Cell Activity in Patients with Neuroproliferative Vestibulodynia.

Introduction: Neuroproliferative vestibulodynia (NPV) is a provoked vestibular pain, shown to be associated with excess immunohistochemical staining for CD117 and PGP9.5, consistent with mast cells and nerves, respectively. It is hypothesized that NPV occurs in genetically predisposed patients in whom mast cells accumulate in the vestibular sub-epithelial stroma where they release various cytokines/growth factors that stimulate the growth of nerves, causing severe allodynia and hyperalgesia throughout the entire vestibule. Objective: To assess, in our patient cohort with histopathologically confirmed diagnosis of NPV, the prevalence of concomitant conditions involving aberrant mast cell activity. Methods: Medical records from people with vulvas who underwent vestibulectomy between June 1, 2019 and December 31, 2022 were retrospectively reviewed. This research protocol was IRB-exempt. Histories from these patients, all of whom had histopathologically confirmed NPV after observing > 8 immunopositive CD117 stained cells per high-power field in the sub-epithelial stroma, were reviewed. The prevalence was noted for the presence of concomitant conditions where aberrant mast cell activity has been reported to play a critical role in symptomatology. The focus was on the following eight conditions: asthma, chronic sinusitis, endometriosis, food allergy/intolerance, interstitial cystitis, irritable bowel syndrome, migraine, and postural orthostatic tachycardia syndrome. Results: A total of 65 NPV patients were included in this chart review. While 24 (37%) reported none, 41 (63%) had at least one other concomitant condition involving aberrant mast cell activity. A total of 25 (38%), 10 (15%), 4 (6%) and 2 (3%) had one, two, three and five other conditions, respectively, involving aberrant mast cell activity. The most common such condition was migraine (n=14; 22%), followed by endometriosis (n=12; 19%), food allergy/intolerance (n=11; 17%), interstitial cystitis (n=10; 15%), irritable bowel syndrome (n=8; 12%), asthma (n=7; 11%), chronic sinusitis (n=5; 8%) and postural orthostatic tachycardia syndrome (n=2; 3%). There was no correlation between the number of concomitant conditions with aberrant mast cell activity reported and the density of CD117-immunopositive staining in the overall cohort of patients with NPV or within the subgroups of those with either lifelong or acquired NPV. Conclusions: Patients with histopathologically confirmed NPV have a high prevalence of concomitant conditions associated with aberrant mast cell activity. While more studies are needed, NPV is likely part of a broader systemic collection of conditions associated with aberrant mast cell activity. This finding is relevant in terms of future diagnostic and treatment options for patients with NPV. Disclosure: No. [ABSTRACT FROM AUTHOR]