Reduced inflammatory state promotes reinnervation of endometriotic-like lesions in TNFRp55 deficient mice.

Endometriosis is a chronic gynecological disease, characterized by growth of endometrial tissue in ectopic sites due to alteration of peritoneal homeostasis and deregulation of apoptosis. Here we have examined whether TNFRp55 deficiency modulates the pro-inflammatory state and the reinnervation of endometriotic-like lesions in mice. Two-month-old female C57BL/6 mice, eight wild type (WT) and eight TNFRp55-/- (KO) were used in the study. Endometriotic-like lesions were induced experimentally. The right uterine horn was removed from the animal, divided longitudinally, cut in three square pieces and sutured to the intestine mesentery. After 4 weeks, the lesions and the peritoneal fluid were collected. The level of TNFα in the peritoneal fluid was evaluated by enzyme-linked immunosorbent assay (EIA). The expressions of COX2, GRα and GRß were evaluated in the lesions by western blot and immunohistochemistry. ß-III TUBULIN, BDNF and NGF protein concentrations were evaluated in the lesions by western blot. Gene expression of Pgp 9.5, SP and Th was analyzed by RT-PCR, whereas relative concentrations of TRKA, NTRp75, phosphorylated NFκB (pNFκB) and total NFκB in lesions were measured by EIA. Compared with the WT group, the KO mice showed lower TNFα levels in the peritoneal fluid and lower numbers of COX2 immunoreactive cells along with increased expression of GRα, ß-III TUBULIN, Pgp 9.5, SP, Th, BDNF, NGF, NTRp75 and pNFκB in the lesions. Future histological studies will be necessary to confirm the sensory/sympathetic imbalance in the endometriotic-like lesions of the KO mice. Our results suggest that a reduced inflammatory state promotes reinnervation of endometriotic-like lesions in TNFRp55-/- mice. Chronic deregulation of TNF receptors can have serious consequences for women with advanced endometriosis.

Assessment of biomarkers in women with endometriosis-associated pain using the ENG contraceptive implant or the 52 mg LNG-IUS: a non-inferiority randomised clinical trial.

OBJECTIVE: The aim of the study was to assess the serum levels of the following biomarkers in women with endometriosis-associated pelvic pain before and after six months of using the etonogestrel (ENG) contraceptive implant or the 52 mg levonorgestrel-releasing intrauterine system (LNG-IUS): cancer antigen (CA)-125, cluster of differentiation (CD) 23 and endometrial nerve fibre density. METHODS: The study was conducted at the Department of Obstetrics and Gynaecology, University of Campinas Medical School, Brazil. A total of 103 women with endometriosis-associated pain diagnosed by surgery, transvaginal ultrasound and/or magnetic resonance imaging were included. Endometrial nerve fibre density and serum levels of CA-125 and soluble CD23 were assessed before and after six months of using the allocated method and were correlated to 10 cm visual analogue scale (VAS) scores for non-cyclical pelvic pain and dysmenorrhoea. RESULTS: Both contraceptive methods significantly reduced concentrations of serum soluble CD23 and endometrial nerve fibre density (p < .001); however, CA-125 was significantly reduced only among users of the ENG implant (p < .05). No correlation was observed between reduction of biomarkers and improvement of VAS pain and dysmenorrhoea scores. No differences were observed between the ENG implant and the LNG-IUS. CONCLUSION: Both progestin-only contraceptives significantly reduced two out of the three biomarkers evaluated. These two biomarkers could, therefore, be used as surrogate markers to follow up medical treatment of endometriosis-associated pain.

Are endometrial nerve fibres unique to endometriosis? A prospective case-control study of endometrial biopsy as a diagnostic test for endometriosis in women with pelvic pain.

STUDY QUESTION: Can the presence of endometrial nerve fibres be used as a diagnostic test for endometriosis in women with pelvic pain? SUMMARY ANSWER: Endometrial fine nerve fibres were seen in the endometrium of women both with and without endometriosis, making their detection a poor diagnostic tool for endometriosis. WHAT IS KNOWN ALREADY: Laparoscopy and biopsy are currently the gold standard for making a diagnosis of endometriosis. It has been reported that small density nerve fibres in the functional layer of the endometrium are unique to women with endometriosis and hence nerve fibre detection could function as a less invasive diagnostic test of endometriosis. However, it may be that other painful conditions of the pelvis are also associated with these nerve fibres. We therefore focused this prospective study on women with pelvic pain to examine the efficacy of endometrial nerve fibre detection as a diagnostic test for endometriosis. STUDY DESIGN, SIZE, DURATION: This prospective case-control study conducted between July 2009 and July 2013 included 44 women with pelvic pain undergoing laparoscopic examination for the diagnosis of endometriosis. Immunohistochemical nerve fibre detection in endometrial curettings and biopsies using anti-protein gene product 9.5 was compared with surgical diagnosis. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Paired endometrial biopsies and curettings were taken from patients with (n = 22, study group) and without (n = 22, control group) endometriosis. Tissue was analysed by immunohistochemistry and nerve fibres were counted whenever they were present in the functional layer of the endometrium. MAIN RESULTS AND THE ROLE OF CHANCE: Fine nerve fibres were present in the eutopic endometrium of patients both with and without endometriosis. The presence of nerve fibres in curettings was not effective for either diagnosing or excluding endometriosis; sensitivity and specificity were 31.8 and 45.5% respectively, positive predictive value was 36.8% and negative predictive value was 40.0%. Few endometrial biopsy specimens were found to have nerve fibres present; sensitivity and specificity for endometrial biopsy were 13.6 and 68.2% respectively, positive predictive value was 30.0% and negative predictive value was 44.1%. LIMITATIONS, REASONS FOR CAUTION: This was a relatively small sample size and studies like this are subject to the heterogeneous nature of the patient population and tissue samples, despite our best efforts to regulate these parameters. WIDER IMPLICATIONS OF THE FINDINGS: Our results demonstrate that fine nerve fibres are present in women with and without endometriosis. Future work should focus on the function of endometrial nerves and whether these nerves are involved with the subfertility or pain that endometriosis sufferers experience. Our study does not support the detection of endometrial nerve fibres as a non-invasive diagnostic test of endometriosis in women with pelvic pain.

Use of hormonal therapy is associated with reduced nerve fiber density in deep infiltrating, rectovaginal endometriosis.

OBJECTIVE: To study the density of nerve fibers in cases of deep infiltrating endometriosis (DIE) of the rectovaginal septum in relation to various clinical factors. DESIGN: A research laboratory-based study. SETTING: A tertiary center together with a research laboratory. METHODS: Archived DIE tissue samples from 45 women operated upon for rectovaginal septum DIE were re-examined histologically, and by immunohistochemistry. MAIN OUTCOME MEASURES: The effect of progestogens or combined oral contraceptives on the density of nerve fibers, and the expression of nerve growth factor (NGF) and its high-affinity receptor (tyrosine kinase receptor A, Trk-A). RESULTS: The use of hormonal therapy was associated with reduced densities of sympathetic, parasympathetic and sensory nerve fibers in DIE lesions. Density of total nerve fibers (with pan-neuronal marker PGP9.5) was significantly lower (p < 0.05) in lesions collected from hormone-treated women (8.6/mm², 4.2-20.8/mm²; median density, from 25th to 75th quartiles) compared with that in lesions from untreated women (24.9/mm², 11.2-34.9/mm²). DIE lesions stained strongly for NGF and its receptor Trk-A. Expression of NGF, but not of Trk-A, was significantly reduced during use of hormonal therapy. CONCLUSIONS: Use of hormonal therapy was associated with significantly reduced nerve fiber density in DIE lesions. This may be an important mechanism of action of hormonal therapy for controlling DIE pain symptoms. The expression of estrogen-regulated NGF and its receptor was only partially suppressed during the use of hormonal therapy, suggesting that local estrogen action is often maintained during conventional hormonal therapy in cases of DIE.

[Expression of nerve growth factor produced by ectopic endometrium from patients with adenomyosis and its relationship with pain scales and innervation].

OBJECTIVE: To investigate the expression of nerve growth factor (NGF) in the ectopic endometrium in adenomyosis patients, and explore the relationship between NGF expression and innervation or pain scales. METHODS: From Mar. 2009 to Oct. 2009, 45 adenomyosis patients undergoing hysterectomy in Obstetrics and Gynecology Hospital of Fudan University were enrolled in this study, which were classified into 33 cases in pain group and 12 cases in non-pain group based on symptom. The degree of dysmenoreal, chronic pelvic pain and dyspareunia was evaluated by visual analogue scale, including no pain, mild to moderate pain and severe pain group. In the mean time, 26 patients with leiomyoma or cervical intraepithelial neoplasia III (CIN III) undergoing hysterectomy were defined as control group. Ectopic endometrium from experimental group and eutopic endometrium from control group were collected in the surgery. The expression of NGF was examined by immunohistochemistry. The density of protein gene product (PGP) 9.5 positive nerve fibers was detected by immuno-fluorescence. RESULTS: The NGF level and the density of PGP 9.5 positive nerve fibers in adenomyosis pain group (0.25 ± 0.08, 16 ± 8 )were higher than adenomyosis painless (0.19 ± 0.05, P = 0.007;11 ± 5, P = 0.018) and control group (0.18 ± 0.05, P = 0.000; 9 ± 4, P = 0.000) . The NGF level and the density of PGP9.5 positive nerve fibers in severe dysmenorrheal group (0.29 ± 0.07, 19 ± 10) were higher than mild to moderate dysmenorrheal (0.22 ± 0.07, P = 0.018;13 ± 4, P = 0.035) and painless group (0.18 ± 0.05, P = 0.000;11 ± 5, P = 0.006) of adenomyosis patients. There was no difference of NGF level and the density of PGP 9.5 positive nerve fibers in chronic pelvic pain group and no chronic pelvic pain group of adenomyosis patients, so was dyspareunia group and no dyspareunia group. CONCLUSION: The increased NGF level of adenomyosis nodules and improving innervation might be involved in the mechanism of adenomyosis related pain.

Expression of neuronal markers in the endometrium of women with and those without endometriosis.

STUDY QUESTION: How do the expression patterns of neuronal markers differ in the endometrium of women with and without endometriosis? SUMMARY ANSWER: The neuronal markers, PGP9.5, NGFp75 and VR1, are expressed in the endometrium at levels that do not differ between women with and without endometriosis. WHAT IS KNOWN ALREADY: Aberrant neuronal growth within the uterus may contribute to abnormal fertility and uterine dysfunction. However, controversy still exists as to whether aberrant innervation in the endometrium is associated with gynaecological pathology such as endometriosis. This may reflect the use of subjective methods such as histology to assess the innervation of the endometrium. We, therefore, employed a quantitative method, western blotting, to study markers of endometrial innervation in the presence and absence of endometriosis. STUDY DESIGN, SIZE, DURATION: This study included 45 women undergoing laparoscopic examination for the diagnosis of endometriosis. Endometrial samples were analysed by western blot for the expression of neuronal and neurotrophic markers, PGP9.5, VR1 and NGFp75. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Endometrial pipelle biopsies were obtained from patients with (n = 20, study group) and without (n = 25, control group) endometriosis. Tissue was analysed by immunohistochemistry and western blot analysis for the expression of pan-neuronal marker, PGP9.5, sensory nociceptive marker, TPVR1, and low-affinity neurotrophic growth factor receptor, NGFRp75. MAIN RESULTS AND THE ROLE OF CHANCE: PGP9.5, NGFp75 and VR1 were expressed in the endometrium of women, independent of the presence of endometriosis. Furthermore, the expression level of PGP9.5, VR1 and NGFp75 did not alter between the two cohorts of women. LIMITATIONS, REASONS FOR CAUTION: Studies of this nature are subject to the heterogeneous nature of patient population and tissue samples despite attempts to standardize these parameters. Hence, further studies using similar methodology will be required to confirm our results. WIDER IMPLICATIONS OF THE FINDINGS: Our results highlight that sensory neuronal markers are present in women with and without endometriosis. Future work will assess what the targets of the endometrial nerves are and investigate their function, their impact on endometrial biology and, in particular, whether aberrant neuronal function, rather than the mere presence of neuronal function, could be the root cause of subfertility and/or pain affecting many endometriosis sufferers. Our results do not, however, confirm the previous paradigm of increased innervation in the endometrium of women with endometriosis, nor the use of nerve cell detection from pipelle biopsies to diagnose endometriosis.

Is the detection of endometrial nerve fibers useful in the diagnosis of endometriosis?

Laparoscopy is currently considered to be the gold standard investigation in patients suspected to have endometriosis, but this is an invasive and relatively costly procedure and there may be significant delays in diagnosis. As the eutopic endometrium is recognized to be abnormal in patients with endometriosis, it has been suggested that endometrial sampling could provide an indirect diagnostic approach. In particular, recent reports have suggested that the presence of nerve fibers within the endometrial functional layer could represent a specific and sensitive marker of concurrent peritoneal endometriosis. However, such studies have been performed in select patient groups and using novel sampling and analytic techniques that are not used routinely in clinical pathology laboratories. The present study was performed upon conventional endometrial biopsies from 68 patients who underwent laparoscopy for suspected endometriosis. The biopsies were stained immunohistochemically for the neural marker PGP 9.5 and examined in a blinded manner. Endometrial functional layer nerve fibers were identified in 15 (22%) biopsies overall including 9/47 (19%) cases with histologically confirmed peritoneal endometriosis and 6/21 (29% cases) without endometriosis. There was no correlation between the presence of functional layer nerve fibers and the presenting symptoms, endometrial histology, or current hormonal therapy. In our experience, endometrial functional layer nerve fibers assessment performed using standard immunohistochemical techniques on routine biopsy specimens proved neither sensitive nor specific for the diagnosis of endometriosis. Pathologists and gynecologists considering this diagnostic approach should carefully consider the methodological factors that may influence its reliability.

Combination of non-invasive and semi-invasive tests for diagnosis of minimal to mild endometriosis.

OBJECTIVES: Non-surgical diagnostic approach for endometriosis would be of great gain to both physicians and patients. The aim of this study was to evaluate the diagnostic value of serum measurement of IL-6 combined with the presence of nerve fibres in the functional layer of endometrium for diagnosis of minimal-mild endometriosis. METHODS: In this prospective study 114 women who underwent laparoscopy for infertility and/or pelvic pain were divided into two groups: control cases (40 cases) with no pathologic findings; and endometriosis patients (74 cases) [subdivided into stages 1-2 or minimal-mild (MM) and stages 3-4 or moderate-severe cases]. Blood was drawn one day before laparoscopy and stored for subsequent analysis of IL-6. Endometrial biopsy was obtained prior to laparoscopy and Immunohistochemistry was performed using the pan-neuronal marker protein gene product 9.5(PGP9.5). Then laparoscopic diagnosis of endometriosis confirmed by histopathology was done. RESULTS: Serum IL-6 with a threshold of 15.4 pg/ml was found to be able to diagnose MM endometriosis with 89.5 % sensitivity and 82.5 % specificity, but sensitivity and specificity of presence of nerve fibres in the functional layer of endometrium were 92 % and 80 % respectively. When two diagnostic modalities were combined the sensitivity and specificity were raised to 100 and 92.5 % respectively. CONCLUSIONS: Combination of both serum IL-6 and presence of nerve fibres in the endometrium is more reliable method for diagnosis of MM endometriosis than in single test.

The eutopic endometrium in endometriosis: are the changes of clinical significance?

The eutopic endometrium in women suffering from endometriosis is different in many ways from that of healthy controls. Both proliferative and secretory eutopic endometria exhibit changes in endometriosis with heterogeneous responses. In addition, nerve fibres appear in the endometrium and myometrium of these women. The endometrium is a rich source of pro-angiogenic factors and vascular events are often disrupted in endometriosis with an overall increase in angiogenesis. A number of investigations have shown that endometriosis is likely the most common cause of endometrial receptivity defects. Endometriosis is also associated with relative 17ß-hydroxysteroid dehydrogenase type II deficiency and these molecular aberrations indicate that local oestrogen production sustains ectopic implants. Recently it has been shown that endometriosis, as a chronic inflammatory disorder, disrupts co-ordinated progesterone response throughout the reproductive tract, including the endometrium, leading to a condition of 'progesterone resistance'. Investigators have searched for biomarkers of endometriosis, but these investigations are fraught with methodological difficulties. In conclusion, molecular phenotyping of the endometrium is changing the disease paradigm, from being foremost an oestrogen-dependent disease to a disorder characterized primarily by progesterone resistance. In recent years, research on the pathogenesis of endometriosis has been focused on alterations in the uterus and particularly the eutopic endometrium. The eutopic endometrium in women suffering from endometriosis is different in many ways from that of healthy controls. Both proliferative and secretory eutopic endometria exhibit changes in endometriosis with heterogeneous responses. The endometrium is a rich source of pro-angiogenic factors and vascular events are often disrupted in endometriosis with an overall increase in angiogenesis. A number of investigations have shown that endometriosis is likely the most common cause of endometrial receptivity defects. Recently, it has been shown that endometriosis, as a chronic inflammatory disorder, disrupts co-ordinated progesterone response throughout the reproductive tract, including the endometrium, leading to a condition of 'progesterone resistance'. Investigators have searched for biomarkers of endometriosis, but these investigations are fraught with methodological difficulties. In conclusion, molecular phenotyping of the endometrium is changing the disease paradigm; from being foremost an oestrogen-dependent disease to a disorder characterized primarily by progesterone resistance.

Diagnosis of endometrial nerve fibers in women with endometriosis.

PURPOSE: Recent studies indicated that there is a high density of small nerve fibers in the functional layer of the endometrium in women with endometriosis and that it can be used as a marker to detect endometriosis. In this study, the efficacy assessment of small nerve fibers' density as a diagnostic marker was compared in patients with and without endometriosis. METHODS: In this study, women with history of pelvic pain and/or infertility who were candidates for laparoscopy or laparotomy in Rassoul hospital (2007-2009) were enrolled. Histological sections of endometrial tissue were prepared from endometrial biopsy from women with endometriosis (n = 12) (1) and without endometriosis (n = 15) (2). Protein gene product 9.5 and neurofilament were evaluated as marker from endometrial biopsies by immunohistochemical methods. RESULTS: There was no statistically significant difference between two groups according to age, body mass index. Nerve fibers were detected in all endometrial biopsies from all women with endometriosis but detected only in three women without endometriosis. The mean density of nerve fibers was 2.2 ± 4.7 mm(-2) in group without endometriosis and) 13.1 ± 3.3 (in group with endometriosis (p < 0.001). Women with endometriosis had significantly higher nerve fiber density in comparison with women without endometriosis. CONCLUSIONS: Our findings indicated that endometrial biopsy for detecting density of nerve fibers by usage of protein gene product 9.5, provided a reliable marker for diagnosis of endometriosis.

Mysteries of endometriosis pain: Chien-Tien Hsu Memorial Lecture 2009.

The more that one looks at the condition endometriosis, the more one realises that it is a unique and complex condition exhibiting a bizarre range of deviations from normal endometrial and myometrial physiology, and presenting with a challenging range of pain-related symptoms. The changing nature of the pain is not well defined, and the molecular mechanisms leading to pain generation are far from clear. Recent research has begun to reveal some of these links between expression of unusual molecules in the eutopic endometrium and ectopic lesions, microanatomical changes in the pelvic nervous system, neuronal dysfunction and the later development of neuropathic pain. A better understanding of these mechanisms will undoubtedly lead to improved use of current medical and surgical treatments, and to the development of novel treatments in the future.

[Protein gene product 9.5-immunoactive nerve fibers and its clinical significance in endometriotic peritoneal lesions].

OBJECTIVE: To investigate the association between distribution of protein gene product (PGP) 9.5-immunoactive nerve fibers in peritoneal endometriotic lesions and disease-associated pain symptoms. METHODS: Thirty two peritoneal endometriotic lesions from patients with endometriosis (16 cases with pain and 16 cases without pain) and matched with 20 peritoneal tissues from patients with uterine leiomyoma without endometriosis were stained immunohistochemically for PGP9.5-immunoactive nerve fibers. RESULTS: The positive rate and density of PGP9.5-immunoreactive nerve fibers in peritoneal endometriotic leision were 62% (10/16) and (3.8+/-1.7)/mm2 in endometriosis patients with pain, which were significantly higher than 19% (3/16) and (1.7+/-0.5)/mm2 in endometriosis patients without pain (P<0.05) and 25% (5/20) and (1.3+/-0.6)/mm2 in peritoneal tissues in women without endometriosis (P<0.05). However, no differences were found between endometriosis patients without pain and women without endometriosis (P>0.05). Moreover, the density of PGP9.5-immunoreactive nerve fibers in peritoneal lesions in endometriosis patients with pain was positively correlated with the severity of pain (r=0.855, P<0.05). In addition, the density of PGP9.5-immunoreactive nerve fibers in peritoneal lesions was statistically higher in endometriosis patients with chronic pelvic pain and (or) dysmenorrhea than those in endometriosis patients with other type of pain (P<0.05), which was not associated with active lesion, site and staging (P>0.05). CONCLUSION: It suggested that PGP9.5-immunoreactive nerve fibers might confer the mechanism of pelvic pain with endometriosis.

Density of small diameter sensory nerve fibres in endometrium: a semi-invasive diagnostic test for minimal to mild endometriosis.

BACKGROUND: The aim of our study was to test the hypothesis that multiple-sensory small-diameter nerve fibres are present in a higher density in endometrium from patients with endometriosis when compared with women with a normal pelvis, enabling the development of a semi-invasive diagnostic test for minimal-mild endometriosis. METHODS: Secretory phase endometrium samples (n = 40), obtained from women with laparoscopically/histologically confirmed minimal-mild endometriosis (n = 20) and from women with a normal pelvis (n = 20) were selected from the biobank at the Leuven University Fertility Centre. Immunohistochemistry was performed to localize neural markers for sensory C, Adelta, adrenergic and cholinergic nerve fibres in the functional layer of the endometrium. Sections were immunostained with anti-human protein gene product 9.5 (PGP9.5), anti-neurofilament protein, anti-substance P (SP), anti-vasoactive intestinal peptide (VIP), anti-neuropeptide Y and anti-calcitonine gene-related polypeptide. Statistical analysis was done using the Mann-Whitney U-test, receiver operator characteristic analysis, stepwise logistic regression and least-squares support vector machines. RESULTS: The density of small nerve fibres was approximately 14 times higher in endometrium from patients with minimal-mild endometriosis (1.96 +/- 2.73) when compared with women with a normal pelvis (0.14 +/- 0.46, P < 0.0001). CONCLUSIONS: The combined analysis of neural markers PGP9.5, VIP and SP could predict the presence of minimal-mild endometriosis with 95% sensitivity, 100% specificity and 97.5% accuracy. To confirm our findings, prospective studies are required.

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.

Rich innervation of deep infiltrating endometriosis.

BACKGROUND: Deep infiltrating endometriosis (DIE) is a specific type of endometriosis, which can be associated with more severe pelvic pain than other forms of endometriotic lesions. However, the mechanisms by which pain is generated are not well understood. METHODS: DIE (n = 31) and peritoneal endometriotic (n = 40) lesions were sectioned and stained immunohistochemically with antibodies against protein gene product 9.5, neurofilament, nerve growth factor (NGF), NGF receptors tyrosine kinase receptor-A (Trk-A) and p75, substance P, calcitonin gene-related peptide, vesicular acetylcholine transporter, neuropeptide Y, vasoactive intestinal peptide and tyrosine hydroxylase to demonstrate myelinated, unmyelinated, sensory and autonomic nerve fibres. RESULTS: There were significantly more nerve fibres in DIE (67.6 +/- 65.1/mm(2)) than in peritoneal endometriotic lesions (16.3 +/- 10.0/mm(2)) (P < 0.01). DIE was innervated abundantly by sensory Adelta, sensory C, cholinergic and adrenergic nerve fibres; NGF, Trk-A and p75 were strongly expressed in endometriotic glands and stroma of DIE. CONCLUSIONS: The rich innervation of DIE may help to explain why patients with this type of lesion have severe pelvic pain.

Endometriosis-associated nerve fibers and pain.

The assessment and diagnosis of endometriosis remain elusive targets. Patient and medical-related factors add to delays in the detection and treatment. Recently, investigators have revealed specific nerve fibers present in endometriotic tissue, with existing parallels between density and pain severity. The aim of this review is to compile a comprehensive review of existing literature on endometriosis-related nerve fiber detection, and the effects of medical therapy on these neural fibers. We performed a systematic literature-based review using Medline and PubMed of nerve fibers detected in eutopic endometrium, endometriotic lesions, and the peritoneum. Various arrangements of significant medical terms and phrases consisting of endometriosis, pelvic pain, nerve fiber detection/density in endometriosis, and diagnoses methodology, including treatment and detection were applied in the search. Subsequent references used were cross-matched with existing sources to compile all additional similar reports. Similar nerve fibers were detected within lesions, endometrium, and myometrium, though at varying degrees of density. Hormonal therapy is widely used to treat endometriosis and was shown to be related to a reduction in fiber density. A direct result of specific nerve fiber detection within eutopic endometrial layers points to the use of a minimally invasive endometrial biopsy technique in reducing delay in diagnosis and subsequent possible preservation of fertility.

Laparoscopic excision of endometriosis may require unilateral parametrectomy.

OBJECTIVE: We investigated the effects of laparoscopic excision of endometriosis with unilateral parametrectomy on bladder, rectal, and sexual function as well as patient satisfaction. METHODS: Women who underwent this procedure between February 1, 2006 and November 15, 2007 were enrolled. Patient characteristics, pre- and postoperative findings, and follow-up data were retrospectively collected from a computerized database. RESULTS: Twelve patients were enrolled in the study. All of the symptoms except dysuria improved after surgery, worsening long after the operation. It seems that all parameters including sexuality, micturition, and defecation are equally important in regards to the final judgement of satisfaction, with a trend towards amelioration long after the operation. CONCLUSIONS: Unilateral parametrectomy may offer successful results in terms of patient satisfaction despite some impairment in bladder, bowel, and sexual function. The risk of permanent functional impairment is high; therefore, surgeons need to maintain the integrity of the contralateral nerve pathway. This is highly important, because pain relief seems to be partially involved in the final judgement of postoperation satisfaction.

[Distribution of nerve fibers in endometrium and its clinical significance in adenomyosis].

OBJECTIVE: To investigate nerve fibers distribution in endometrium of adenomyosis and their relationship with dysmenorrhea. METHODS: Endometrial tissue was sampled from 74 hysterectomy specimens including 32 cases with adenomyosis and 42 cases with uterine fibroids. Two-step Envision immunohistochemical staining was used to detect distribution of nerve fibers in endometrium. Highly specific polyclonal rabbit anti-protein gene product 9.5 (PGP9.5) and monoclonal mouse anti-neurofilament protein (NF) were used to demonstrate both myelinated and unmyelinated nerve fibers in endometrium in women with adenomyosis and uterine fibroids. RESULTS: The positive rate of PGP9.5 immunoreactive nerve fibers in the functional layer of endometrium of pain patients were with 64% (14/22) in adenomyosis and 67% (10/15) in uterine fibroids. And their density were 0.6 (0 - 9.4)/mm(2) and 0.6 (0 - 6.0)/mm(2) without reaching statistical difference (P > 0.05). No expression of NF could be detected in the functional layer of endometrium of adenomyosis and uterine fibroids. There were no PGP9.5 immunoreactive nerve fibers in the functional layer of endometrium in non-pain women with adenomyosis and uterine fibroids. Moreover, No NF immunoreactive nerve fibers in the functional layer of endometrium were shown in non-pain patients with adenomyosis and uterine fibroids. PGP9.5 immunoreactive nerve fibers and the nerve density in the basal layer of endometrium were 64% (14/22), 1.1 (0 - 12.0)/mm(2) in pain adenomyosis and 50% (5/10), 0.6 (0 - 3.0)/mm(2) in non-pain adenomyosis. NF immunoreactive nerve fibers and the density in the basal layer of endometrium were 23% (5/22), (0 - 0.6)/mm(2) in pain adenomyosis and 20% (2/10), (0 - 1.0)/mm(2) in non-pain adenomyosis. PGP9.5 immunoreactive nerve fibers and the nerve density in the basal layer of endometrium were 80% (12/15) and 1.6 (0 - 10.0)/mm(2) in pain fibroids and 44% (12/27), 0 (0 - 5.0)/mm(2) in non-pain fibroids. NF immunoreactive nerve fibers and the nerve density in the basal layer of endometrium were 40% (6/15), 0 (0 - 0.4)/mm(2) in pain fibroids and 15% (4/27), 0 (0 - 1.0)/mm(2) in non-pain fibroids. There was no statistical different PGP9.5 and NF immunoreactive nerve fibers distribution in basal layer of endometrium between pain adenomyosis and pain fibroids or between non-pain adenomyosis and non-pain fibroids (all P > 0.05). However, PGP9.5 immunoreactive nerve fibers density in basal layer of endometrium was higher in pain adenomyosis and fibroids when compared with non-pain adenomyosis and fibroids (P < 0.05). CONCLUSIONS: PGP9.5 immunoreactive nerve fibers might confer the occurrence of pelvic pain, however, NF immunoreactive nerve fibers may not involved in the pathogenesis of pain.

Invasion of human deep nodular endometriotic lesions is associated with collective cell migration and nerve development.

OBJECTIVE: To study the mechanisms of invasion and innervation of deep endometriosis in women. DESIGN: Morphologic and immunohistochemical analysis of human endometriotic lesions. SETTING: Academic research unit. PATIENT(S): Seventeen biopsy samples of deep endometriotic lesions were collected from patients undergoing surgery for deep endometriosis. INTERVENTION(S): The endometriotic samples were divided into two parts: the front (the most invasive area of lesions, approaching rectal infiltration) and center (the area close to the posterior part of the cervix). MAIN OUTCOME(S): To elucidate: gland morphology, proliferation, and expression of adhesion molecules (ß-catenin, E-cadherin, and N-cadherin) to determine the possible role of collective cell migration (CCM) in the invasion process; and nerve growth factor (NGF) and nerve fiber density (NFD) values to shed further light on the mechanism of innervation. RESULTS: Glands from the front showed significantly reduced thickness, but significantly higher proliferation. ß-Catenin expression was similar between the lesion center and front. E-cadherin levels were significantly lower and N-cadherin levels significantly higher in glands located at the front of the lesions. Expression of matrix metalloproteinase-9 was significantly higher in glands and stromal cells located at the invasion front. NFD and NGF expression were also significantly higher at the lesion front. CONCLUSION: Although some data in the literature point to features of epithelial to mesenchymal transition in human deep nodular endometriosis, our study suggests that gland invasion in these lesions is dominated by CCM. Innervation of deep nodular endometriotic lesions may be a consequence of nerve recruitment from surrounding organs.

A pilot study to evaluate the relative efficacy of endometrial biopsy and full curettage in making a diagnosis of endometriosis by the detection of endometrial nerve fibers.

OBJECTIVE: The purpose of this study was to evaluate endometrial biopsy and curettage in detecting small nerve fibers in eutopic endometrium for diagnosis of endometriosis. STUDY DESIGN: Endometrial biopsies with precise, consistent technique and curettings were taken from 37 women (20 with endometriosis and 17 without endometriosis). Sensitivity, specificity, and positive and negative predictive value were formally calculated. Endometrial nerve fibers were immunohistochemically detected using the pan-neuronal marker PGP9.5. RESULTS: Small nerve fibers were detected in all endometrial biopsies and curettings from all 20 women with endometriosis, but were not detected in endometrium taken from 17 women without endometriosis. Mean (+/-SD) nerve fiber density in the endometrial biopsies was 26.8 per mm(2) +/- 55.9 (range, 1.6-125) and for curettings was 21.6 per mm(2) +/- 33.1 (range, 0.8-250), with 100% specificity, sensitivity, and positive and negative predictive value. CONCLUSION: Careful endometrial biopsy combined with immunohistochemical staining for nerve fibers may be a reliable means of diagnosing or excluding endometriosis.