Endometrial nerve fibres in endometriosis

Endometriosis is a common gynaecological disease that can cause severe pelvic painsuch as dysmenorrhoea and dyspareunia, however the mechanisms by which pain isgenerated are not well understood. Nerve fibres in endometriotic plaques have beenreported by several authors. We have recently demonstrated the presence ofunmyelinated sensory nerve fibres (using the pan-neuronal marker PGP9.5) in thefunctional layer of endometrium in women with endometriosis and a significantlyincreased nerve fibre density in endometrium and myometrium in women withendometriosis compared with women without endometriosis. Sensory C nerve fibreswere only detected in the functional layer of endometrium of women with endometriosisand never in women without endometriosis. This finding is so consistent that it maybecome an effective means of making the diagnosis of endometriosis. Nerve fibresexpressing a range of neuronal markers and an over-expression of nerve growth factor(NGF) and nerve growth factor receptor (NGFRp75) were also demonstrated inperitoneal endometrial plaques in women with endometriosis. Effects of currentlyavailable medications for endometriosis on nerve fibres in eutopic endometrium inhormonally treated women have been also studied. This review will describe nervefibres in eutopic endometrium and ectopic endometriotic plaques in women withendometriosis.