The Relationship Between Dysmenorrhoea And Nerve Fibres In The Endometrium In Women With Endometriosis

Objective To investigate the associations of nerve fibres in functional layer endometrium with dysmenorrhoea in women with endometriosis.Methods Histological sections of endometrial tissue were prepared from endometrial curettage on 28 women with endometriosis(17 cases with dysmenorrhoea, 11 cases without dysmenorrhoea). Endometrial tissues were sampled from hysterectomy specimens performed on 37 endometriosis women with adenomyosis (31 cases with dysmenorrhoea, 6 cases without dysmenorrhoea). A highly specific polyclonal rabbit anti-protein gene product 9.5 (PGP9.5) by immunohistochemical staining was used to demonstrate both myelinated and unmyelinated nerve fibres in the functional layer of endometrium in women with endometriosis alone and in endometriosis women with adenomyosis.Results PGP9.5-immunoreactive nerve fibers were only detected in the functional layer of the endometrium in women with dysmenorrhoea, accounting for 71% (12/17) and 58% (18/31) of women with endometriosis alone and of endometriosis women with adenomyosis, respectively, but not present in women without dysmenorrhoea. For the women with dysmenorrhoea, the median (Range) of PGP9.5-immunoreactive nerve fiber density was 0.60[0-3.40] /mm~2 and 0.20[0-2.80] /mm~2 in women with endometriosis alone and endometriosis women with adenomyosis, respectively. There were no significant differences of PGP9.5 positive rate or PGP9.5-immunoreactive nerve fiber density between endometriosis alone and endometriosis with adenomyosis in women with dysmenorrhoea (P>0.05). In addition, there was a significant correlation between the density of PGP9.5-immunoreactive nerve fibers in functional layer endometrium and the severity of dysmenorrhoea in women with endometriosis (P<0.001).Conclusions These results suggest that the presence of PGP9.5- immunoreactive nerve fibers in functional layer endometrium is associated with dysmenorrhoea but not with endometriosis disease itself, and may play a role in the pathogenesis of dysmenorrhoea.