Localization of chromogranin, synaptophysin, serotonin, and CXCR2 in neuroendocrine cells of the minor vestibular glands: an immunohistochemical study.

Sections of vulvar tissue containing minor vestibular glands (15 sections from 14 women with vulvar vestibulitis syndrome and six control sections from five asymptomatic women) were immunohistochemically stained with antibodies against chromogranin, synaptophysin, serotonin, and CXCR2. The degree of inflammation in vestibular tissue from women with and without vulvar vestibulitis syndrome was not significantly different. All vulvar minor vestibular glands contained neuroendocrine cells that expressed chromogranin to some degree. Only one case failed to express synaptophysin. The number of cells expressing chromogranin and synaptophysin was the same regardless of the degree of inflammation. However, moderate to severe inflammation was associated with a statistically significant increase in the number of cells expressing serotonin (p < 0.001) and CXCR2 (p < 0.02). It is concluded that neuroendocrine cells are present within minor vestibular glands of the vulva. The number of cells expressing the inflammatory mediator serotonin and CXCR2, the shared interleukin-8 receptor, are upregulated with inflammation. Chronic inflammation is a normal finding in vestibular tissue and does not serve as a histologic marker for vulvar vestibulitis.