Diagnosis of endometriosis by detection of nerve fibres in an endometrial biopsy: a double blind study.

BACKGROUND: Diagnosis of endometriosis currently requires a laparoscopy and this need probably contributes to the considerable average delay in diagnosis. We have reported the presence of nerve fibres in the functional layer of endometrium in women with endometriosis, which could be used as a diagnostic test. Our aim was to assess efficacy of nerve fibre detection in endometrial biopsy for making a diagnosis of endometriosis in a double-blind comparison with expert diagnostic laparoscopy. METHODS: Endometrial biopsies, with immunohistochemical nerve fibre detection using protein gene product 9.5 as marker, taken from 99 consecutive women presenting with pelvic pain and/or infertility undergoing diagnostic laparoscopy by experienced gynaecologic laparoscopists, were compared with surgical diagnosis. RESULTS: In women with laparoscopic diagnosis of endometriosis (n = 64) the mean nerve fibre density in the functional layer of the endometrial biopsy was 2.7 nerve fibres per mm(2) (+/-3.5 SD). Only one woman with endometriosis had no detectable nerve fibres. Six women had endometrial nerve fibres but no active endometriosis seen at laparoscopy. The specificity and sensitivity were 83 and 98%, respectively, positive predictive value was 91% and negative predictive value was 96%. Nerve fibre density did not differ between different menstrual cycle phases. Women with endometriosis and pain symptoms had significantly higher nerve fibre density in comparison with women with infertility but no pain (2.3 and 0.8 nerve fibre per mm(2), respectively, P = 0.005). CONCLUSIONS: Endometrial biopsy, with detection of nerve fibres, provided a reliability of diagnosis of endometriosis which is close to the accuracy of laparoscopic assessment by experienced gynaecological laparoscopists. This study was registered with the Australian Clinical Trials Registry (ACTR) 00082242 (registered: 12/12/2007). The study was approved by the Ethics Review Committee (RPAH Zone) of the Sydney South West Area Health Service (Protocol number X05-0345) and The University of Sydney Human Research Ethics Committee (Ref. No. 10761) and all women gave their informed consent for participation.

High density of small nerve fibres in the functional layer of the endometrium in women with endometriosis.

BACKGROUND: Endometriosis is a common gynaecological disease and is frequently associated with recurrent and serious pelvic pain such as dysmenorrhoea and dyspareunia, but the mechanisms by which these symptoms are generated are not well understood. METHODS: Histological sections of endometrial tissue were prepared from endometrial curettings and hysterectomies performed on women with endometriosis (n=25 and n=10, respectively) and without endometriosis (n=47 and n=35, respectively). These were stained immunohistochemically for the highly specific polyclonal rabbit anti-protein gene product 9.5 (PGP9.5) and monoclonal mouse anti-neurofilament protein (NF) to demonstrate both myelinated and unmyelinated nerve fibres. RESULTS: Small nerve fibres were identified throughout the basal and functional layers of the endometrium in all endometriosis patients, but were not seen in the functional layer of the endometrium in any of the women without endometriosis (P<0.001). NF-immunoreactive nerve fibres were present in the basal layer in all endometriosis patients but not in non-endometriosis patients, with one exception (P<0.001). CONCLUSIONS: Small nerve fibres detected in the functional layer in all women with endometriosis may have important implications for understanding the generation of pain in these patients. The presence of nerve fibres in an endometrial biopsy may be a novel surrogate marker of clinical endometriosis.

Electrical stimulation-evoked release of endogenous taurine from slices of the hippocampus, cerebral cortex and cerebellum of the rat.

Release of endogenous taurine by electrical stimulation of slices of the hippocampus, cerebral cortex, cerebellum and medulla oblongata of the rat was studied and compared with that of alanine and/or gamma-aminobutyric acid (GABA). Electrical stimulation caused a calcium-dependent release of taurine from slices of the hippocampus, cerebral cortex and cerebellum but not from slices of the medulla oblongata. The stimulus-evoked release of taurine in the hippocampus was rapid in onset and declined to baseline fast, which was essentially similar to the time course pattern of the stimulus-evoked release of GABA. In addition, there were distinct regional differences in the relative amounts of taurine released. Electrical stimulation did not release alanine from any regions examined. These results support the hypothesis that taurine plays a neurotransmitter role in the hippocampus, cerebral cortex and cerebellum of the rat.