Decreased peritoneal concentrations of interleukin-15 in women with advanced stage endometriosis

OBJECTIVE: To assess the concentrations of interleukin-15 (IL-15) in peritoneal fluid from women with endometriosis and fertile disease-free controls. STUDY DESIGN: Peritoneal fluid samples were obtained from 50 women with endometriosis and 29 fertile women having tubal ligation. Concentrations of IL-15 were measured. RESULTS: The mean (S.D.s) concentration of IL-15 in peritoneal fluid was 11.17 pg/mL (3.89) for women with endometriosis, and 12.59 pg/mL (4.11) for fertile disease-free controls. The difference of peritoneal IL-15 concentrations between endometriosis and control women was not statistically significant. However, peritoneal IL-15 concentrations were significantly lower in women with moderate/severe endometriosis when compared with those in women with minimal/mild endometriosis, and in controls (P<0.05). In addition, peritoneal IL-15 concentrations did not correlate with the phase of menstrual cycle in endometriosis or control women. CONCLUSIONS: Our results suggest that the decreased peritoneal IL-15 concentrations in women with moderate/severe endometriosis imply a role of IL-15 in the pathogenesis of advanced endometriosis as compared to those with minimal/mild endometriosis and fertile disease-free controls.     

Serum and peritoneal fluid proteins in women with and without endometriosis

We examined the proteins in serum and peritoneal fluid of women with endometriosis (and of healthy controls) for evidence of an autoimmune response that might account for their impaired fertility. No antibodies against endometrial glycoproteins or against "progestin dependent endometrial protein" (PEP) were found in any serum or peritoneal fluid sample. Levels of PEP were not different in serum from women with moderate to severe endometriosis (n = 6), with mild endometriosis (n = 21), or from disease-free cycling controls (n = 19). PEP levels in peritoneal fluid from mild endometriosis and from controls did not differ but were elevated ten times in fluid obtained in the secretory phase from women with moderate to severe disease. This suggests that PEP levels in peritoneal fluid reflect the extent of ectopic endometrial growth. The salient finding was a heretofore undescribed protein (mol wt 70,000) in secretory phase peritoneal fluid samples (18/20) and its absence during the proliferative phase (0/35).     

Ferritin levels in the peritoneal fluid--a new endometriosis marker?

Accumulating data suggests that iron homeostasis in the peritoneal cavity may be disrupted by endometriosis. Increased iron metabolism induce proinflammatory and prooxidative environment in the peritoneal fluid (PF), thus may be involved in the pathogenesis of the endometriotic disease. Ferritin, a protein consisting of 24 subunits, may represent 25% of the total iron found in the organism. The aim of the study was to estimate the levels of ferritin in peritoneal fluid of women with endometriosis. MATERIALS AND METHODS: Forty women were studied, including 15 patients with minimal/ mild endometriosis, 15 patients with moderate/ severe stage of the disease and 10 women without the disease. Ferritin concentrations were measured in the PF using a commercially available ELISA kit. RESULTS: Ferritin levels were significantly higher in PF from both women with stages I/II (p=0.003) and III/IV (p=0.0007) endometriosis as compared to the reference group. No significant difference in the PF ferritin levels was found between women with stages I/II and stages III/IV endometriotic disease (p=0.98). CONCLUSIONS: Increased ferritin levels, observed in peritoneal fluid, may reflect disrupted iron metabolism in the peritoneal cavity of endometriosis women.     

Elevated soluble Fas ligand levels may suggest a role for apoptosis in women with endometriosis

OBJECTIVE: To evaluate soluble Fas ligand concentrations in serum and peritoneal fluid from women with endometriosis and from fertile controls without endometriosis, and to study levels of soluble Fas ligand in conditioned media of cultured endometrial stromal cells. DESIGN: Prospective, experimental trial. SETTING: Two academic IVF centers. PATIENT(S): Twenty-nine fertile women without endometriosis and 57 infertile women with endometriosis (32 with stage I or II disease and 25 with stage III or IV disease). MAIN OUTCOME MEASURE(S): Enzyme-linked immunosorbent assay was used to measure soluble Fas ligand concentrations in paired samples of serum and peritoneal fluid from women with and without endometriosis. Concentrations were also measured in conditioned media of cultured endometrial stromal cells at basal conditions and after stimulation with interleukin-8 (0.001-10 ng/mL) and tumor necrosis factor-alpha (1-10 ng/mL). RESULT(S): Compared with fertile controls and women with early-stage of endometriosis, women with moderate to severe endometriosis had elevated serum (87.2 +/- 6.4, 88.2 +/- 6.9, and 162.3 +/- 7.8 pg/mL, respectively) and peritoneal fluid (81.0 +/- 6.0, 80.5 +/- 6.8, and 166.2 +/- 10.3 pg/mL, respectively) concentrations of soluble Fas ligand. Serum levels of soluble Fas ligand positively correlated with levels in peritoneal fluid. Comparison of patients in the same menstrual cycle in each group revealed that increased levels of soluble Fas ligand in patients with advanced endometriosis were not attributable to the difference in cycle phases. Soluble Fas ligand was not detected in conditioned media of endometrial stromal cells under baseline conditions or after stimulation. CONCLUSION(S): Serum and peritoneal fluid of women with moderate to severe endometriosis contain elevated concentrations of soluble Fas ligand compared to women with minimal or mild endometriosis and women without endometriosis. These findings suggest a role for apoptotic dysregulation in the pathophysiology of endometriosis.     

Peritoneal fluid volume, 17beta-estradiol and progesterone concentrations in women with endometriosis and/or luteinized unruptured follicle syndrome

Data on the presence of an ovulation ostium and the volume and the concentrations of estradiol (17 beta-estradiol) and progesterone In women with endometriosis (n = 80) and women with luteinized unruptured follicle (LUF) syndrome (n = 32) are reported and compared with data obtained from normal ovulatory women, previously reported. in women with endometriosis, less ovulation ostia were observed, the difference being significant in moderate and severe endometriosis. During the luteal phase, no statistical difference was found in the amount of peritoneal fluid of women with endometriosis. Estradiol and progesterone levels in the peritoneal fluid of normal women and women with mild endometriosis were not significantly different. Lower steroid concentrations found in peritoneal fluid of women with moderate (phase days 20-22) and severe endometriosis (phase days 14-19 and 20-22) may explain the high incidence of infertility reported in these women (peritoneal steroids deficiency). During the phases days 14-19 and 20-22, very low peritoneal steroid concentrations were found in women with LUF syndrome. It is suggested that progesterone assay in peritoneal fluid is an aid to diagnose the luteinized unruptured syndrome.     

Peritoneal fluid concentrations of interleukin-17 correlate with the severity of endometriosis and infertility of this disorder

This prospective study aimed to determine whether patients with endometriosis are having different level of interlukin-17 (IL-17) in peritoneal fluid when compared with patients without endometriosis. The patients with minimal/mild endometriosis had a significantly higher level of IL-17 in peritoneal fluid compared with those with moderate/severe endometriosis or without endometriosis. The concentration of IL-17 in peritoneal fluid was significantly higher when endometriosis and infertility coexist. However, the concentration of IL-17 in peritoneal fluid did not correlate with the phase of the menstrual cycle in the patients with or without endometriosis. Our study suggested that IL-17 might play an important role in the pathogenesis of early endometriosis and endometriosis-associated infertility.     

Pyruvate reduces in vitro the embryotoxic effect of peritoneal fluid from infertile women with endometriosis

OBJECTIVES: To ascertain the embryotoxicity of peritoneal fluid from infertile women with endometriosis (PF-E), on mouse embryos in culture and to examine the effect of pyruvate in the culture medium on PF-E induced embryotoxicity. STUDY DESIGN: Blood-free peritoneal fluid samples were obtained during laparoscopic investigation for infertility from 21 infertile women with endometriosis. The severity of endometriosis ranged from minimal or mild (PF-min to mild-E; n=7), moderate (PF-mod-E; n=7), to severe (PF-sev-E; n=7). Peritoneal fluid samples were centrifuged at 600 x g for 10 min and 4 degrees C, and the supernatant was incubated at 56 degrees C for 30 min in a water bath to inactivate the complement protein. Mice were super ovulated with intraperitoneal injection (IP) of 5IU of pregnant mare serum gonadotrophin and human chorion gonadotrophin. Twenty-four hours after confirmation of mating two-cell mouse embryos were obtained. They were then cultured in modified Whitten's medium (mWM) with peritoneal fluid from patients with endometriosis, and either in the absence or presence of excess pyruvate (0.062 mmol(-1)). Embryos were cultured for 72 h. RESULTS AND CONCLUSION: Addition of 5% PF-E significantly (p<0.001) suppressed embryo growth at 24, 48, and 72 h of culture and the degree of suppression correlated with the severity of the disease. The presence of 0.062 mmol(-1) pyruvate in the culture medium significantly (p<0.001) reduced the embryotoxicity of PF-min to mild-E and PF-mod-E at each stage of development, but was only seen at 24h of culture (p<0.001) in cultures with PF-sev-E even when the concentration of pyruvate in the medium was increased to 0.31 mmol(-1). This study confirms the embryotoxicity of PF-E in vitro, which was reduced by the presence pyruvate in the culture medium, particularly in cultures containing fluid from women with endometriosis of minimum or mild to moderate severity.     

Diagnostic accuracy of interleukin-6 levels in peritoneal fluid for detection of endometriosis

Purpose

To determine, with extended receiver operating characteristic (ROC) curve analysis, the diagnostic value of cytokines showing significantly different peritoneal concentrations between women with and without endometriosis.

Methods

Multiplex cytokine concentration measurement of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ levels in peritoneal fluid of women with minimal to mild (n = 10) and moderate to severe (n = 26) endometriosis, and 42 controls.

Results

Only IL-6 and IL-10 concentrations were significantly higher in endometriosis patients than in controls. Specifically, significantly higher IL-6 and IL-10 levels were found in moderate to severe but not in minimal to mild endometriosis as compared to controls. For evaluation of diagnostic significance, ROC analysis determined discriminating parameters for IL-6, while those calculated for IL-10 were useless. Importantly, ROC analysis for IL-6 levels limited to women with moderate to severe endometriosis showed the highest area under the curve with the sample size sufficient to achieve 90 % power of the test. Finally, extended ROC including cost of analysis for this group of patients determined the optimal cut-off leading to high specificity and positive likelihood ratio resulting in 79 % effectiveness of the test.

Conclusions

While our outcomes show moderate usefulness of peritoneal IL-6 levels in discrimination of moderate to severe endometriosis, further studies might be needed to determine the usefulness of peritoneal IL-6 levels in detection of early stages of endometriosis, as such a finding would be more relevant in clinical decision making.     

Cytokine profiles in serum and peritoneal fluid from infertile women with and without endometriosis

OBJECTIVE: To study the serum and peritoneal fluid cytokine profiles in infertile women with minimal/mild active endometriosis. METHODS: Fifty-seven consecutive infertile women undergoing laparoscopy for unexplained infertility had peritoneal fluid and serum samples obtained at the time of laparoscopy. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-1 beta (IL-1 beta), vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), monocyte chemotatic protein-1 (MCP-1), RANTES, platelet derived growth factor (PDGF), soluble Fas (sFas), and soluble Fas Ligand (sFasL) in peritoneal fluid and serum were measured to compare the concentration in both biological fluids, in women who have minimal/mild red endometriosis using women with no endometriosis as controls. RESULTS: Peritoneal fluid levels of MCP-1, IL-8 and IL-6 were significantly higher in the endometriosis group (P < 0.012, P = 0.003, and P = 0.015, respectively). There was no significant difference in the peritoneal fluid levels of IL-1 beta, TNF-alpha, RANTES, VEGF, PDGF, sFas and sFasL in the two groups. Although serum levels of IL-8 were higher in women with endometriosis, the difference was not significant (P = 0.07). Serum levels of PDGF, IL-6, RANTES, IL-1 beta, TNF-alpha, and sFas, were not significantly different in the two groups. CONCLUSION: The elevated levels of MCP-1, IL-6, and IL-8 in peritoneal fluid but not serum may indicate the importance of local macrophage activating factors in the pathogenesis of endometriosis.     

Tumor necrosis factor-alpha but not interleukin-1 beta or interleukin-8 concentrations correlate with angiogenic activity of peritoneal fluid from patients with minimal to mild endometriosis

OBJECTIVE: To assess the angiogenic activity of peritoneal fluid in women with minimal to mild endometriosis and to investigate the relationship between this activity and the concentration of macrophage-derived angiogenic factors and clinical variables, such as phase of menstrual cycle, type of lesion, and revised American Society for Reproductive Medicine classification. DESIGN: In vivo bioassay. SETTING: Tertiary-care university medical center. PATIENT(S): Fifty-two female volunteers with laparoscopic findings indicating minimal to mild endometriosis. INTERVENTION(S): Peritoneal fluid was collected at the start of laparoscopy. A standard amount of peritoneal fluid was applied to a chick embryo chorioallantoic membrane assay. MAIN OUTCOME MEASURE(S): Angiogenic response was assessed by determining the vascular density index. RESULT(S): 85% of the peritoneal fluid samples induced angiogenesis in the chick embryo chorioallantoic membrane bioassay. Tumor necrosis factor-alpha and total protein were significantly related to the vascular density index, whereas interleukin-1beta, interleukin-8, and clinical variables appeared to not affect the angiogenic response. CONCLUSION(S): The results confirms previous findings of peritoneal fluid angiogenic activity in women with minimal to mild endometriosis and indicate involvement of tumor necrosis factor-alpha.     

Total antioxidant status of peritoneal fluid in infertile women

OBJECTIVE: To determine whether impairment of the antioxidant systems of peritoneal fluid might be a factor responsible for infertility. STUDY DESIGN: Total antioxidant status was measured in peritoneal fluid obtained from 18 infertile women suffering from minimal or mild endometriosis, 23 patients with unexplained infertility, 12 women with tubal infertility and 13 fertile women. RESULTS: Total antioxidant status was significantly lower in peritoneal fluid from women with unexplained infertility (0.49+/-0.21 mmol/l) compared to both fertile patients (0.67+/-0.24 mmol/l, P=0.02) and women with tubal infertility (0.76+/-0.26 mmol/l, P=0.001). Peritoneal fluid total antioxidant status did not differ significantly between patients with endometriosis (0.61+/-0.2 mmol/l), tubal infertility and the fertile group (P>0.05). CONCLUSIONS: Our results suggest that low antioxidant status in peritoneal fluid may play a role in the pathogenesis of infertility.     

子宫内膜异位症患者腹腔液及血清中前列腺素E2与bcl-2蛋白的含量变化及意义

目的探讨子宫内膜异位症(内异症)患者腹腔液及血清中,前列腺素E2(PGE2)和bcl-2蛋白的含量变化及其与内异症发病的关系。方法采用酶联免疫吸附法(ELISA)检测36例内异症患者(内异症组,其中Ⅰ、Ⅱ期患者16例,Ⅲ、Ⅳ期患者20例)和30例因卵巢囊肿或浆膜下子宫肌瘤手术患者(对照组)腹腔液及血清PGE2与bcl-2含量。结果内异症组患者腹腔液中PGE2、bcl-2蛋白的含量分别为(1987±532)ng/L、(177±53)U/L,对照组为(386±215)ng/L、(86±21)U/L,两组比较,差异均有统计学意义(P<0.01)。Ⅲ、Ⅳ期内异症患者腹腔液中PGE2的含量[(2221±1352)ng/L]较Ⅰ、Ⅱ期患者[(1694±381)ng/L]明显升高,差异也有统计学意义(P<0.01);Ⅲ、Ⅳ期内异症患者腹腔液中bcl-2的含量[(190±63)U/L]较Ⅰ、Ⅱ期患者[(162±49)U/L]升高,差异有统计学意义(P<0.05)。内异症组血清中的PGE2与bcl-2含量[(3787±514)ng/L、(96±44)U/L]均高于对照组[(129±97)ng/L、(53±40)U/L],差异均有统计学意义(P<0.01)。Ⅲ、Ⅳ期内异症患者血清中的PGE2含量[(964±290)ng/L]也高于Ⅰ、Ⅱ期患者[(590±362)ng/L],差异也有统计学意义(P<0.01);内异症患者腹腔液中PGE2及bcl-2的含量均高于血清。结论内异症患者腹腔中高含量的PGE2与bcl-2,可能对内异症发病有影响;内异症患者腹腔液与血清中PGE2和bcl-2含量与病变的范围有一定关系。     

Glutathione peroxidase concentration in the peritoneal fluid from infertile women

OBJECTIVES: To assess the concentration of Plasma Glutathione Peroxidase (plGPx) in the peritoneal fluid (PF) of patients with unexplained infertility and infertile women with minimal and mild endometriosis. MATERIALS AND METHODS: 33 women were studied, including 8 infertile women with minimal or mild endometriosis, 15 patients with unexplained infertility and 10 patients with tubal occlusion (a reference group). Concentration of plGPx was measured in the PF using a commercially available ELISA kit (Oxis Inc.). RESULTS: The plGPx concentration was significantly (p = 0.04) lower in PF from women with unexplained infertility (846 +/- 177 ng/ml) compared to the reference group (1023 +/- 238 ng/ml), but did not differ significantly (p = 0.25) between women with endometriosis (918 +/- 81 ng/ml) and patients with tubal infertility. CONCLUSIONS: Our results suggest that low peritoneal plGPx concentration may play a role in the pathogenesis of infertility.     

Effect of peritoneal fluid from patients with mild and severe endometriosis on endometrial stromal cell proliferation

The aim of this study was to evaluate and compare the mitogenic effect of peritoneal fluid (PF) from women with mild and severe endometriosis on the endometrial stromal cell proliferation. Increasing concentrations of PF from women with and without mild or severe endometriosis were added to primary endometrial stromal cell cultures and³H-thymidine incorporation was used to assess DNA synthesis in these cultures. PF from women with mild endometriosis induced a statistically significant dose-dependent increase in stromal cell thymidine uptake ranged from 5.8 to 14.5 fold, whereas PF from women with severe endometriosis produced an average 51% inhibition of stromal cell proliferation of compared with cells exposed to non-endometriosis PF or exposed to nutrient medium supplemented with 2.5% calf serum alone. PF samples from patients with stage I endometriosis induced a statistically dose-dependent increase in stromal cell proliferation, whereas PF from patients with stage IV endometriosis caused a significant inhibition.     

Serum and peritoneal fluid levels of interleukin-6 and interleukin-37 as biomarkers for endometriosis

This study aimed to compare the levels of interleukin (IL)-1β, IL-6, IL-10, and IL-37 in the serum and peritoneal fluid of women with and without endometriosis. In addition, it aimed to determine the diagnostic values of the cytokines with significantly different concentrations. The levels of IL-1β, IL-6, IL-10, and IL-37 in the serum and peritoneal fluid samples of 40 women with endometriosis and 32 women without endometriosis were measured using an enzyme-linked immunosorbent assay. The serum and peritoneal fluid levels of IL-1β and IL-10 were not statistically significantly different between the endometriosis and control groups. The IL-6 and IL-37 levels in the serum and peritoneal fluid were higher in the endometriosis group than in the control group, and they were correlated with the stage of endometriosis. The AUC for the IL-37 was 0.897 for the serum and 0.934 for the peritoneal fluid, while the AUC for the IL-6 was 0.905 for the serum and 0.952 for the peritoneal fluid. Our results suggest that the serum and peritoneal fluid IL-6 and IL-37 levels were significantly increased in the endometriosis patients, indicating that these cytokines may serve as biomarkers for the diagnosis of endometriosis.     

Different concentrations of interleukins in the peritoneal fluid of women with endometriosis: relationships with lymphocyte subsets.

The present study explored the possible relationships between immune cell subsets and interleukin (IL)-12 or IL-13 levels in the peritoneal fluid of patients with and without endometriosis. Peritoneal fluid samples were obtained from 80 women while they were undergoing laparoscopy for pain, infertility, tubal ligation or re-anastomosis. The American Fertility Society scoring system was used to determine the extension of endometriosis. The peritoneal fluid mononuclear cells were analyzed for immunophenotyping using cytometry, whereas peritoneal fluid concentrations of interleukins were measured using two ultrasensitive commercially available enzyme-linked imnunosorbent assay kits. Significantly higher peritoneal fluid IL-12 levels were found in women with moderate or severe endometriosis (stages III and IV) than in healthy controls (p < 0.01). Conversely, subjects with endometriosis showed remarkably lower peritoneal fluid IL-13 concentrations than controls, independent of the severity of the disease (p < 0.05). Considering immune system effectors, patients with endometriosis presented a significantly higher peritoneal fluid CD8+/CD4+ ratio when compared with healthy controls. Moreover, the number of peritoneal fluid CD8+ and CD4+ activated T cells was significantly lower in the former than in the latter group, independent of the endometriosis stage. Connections were observed between peritoneal fluid interleukins and peritoneal fluid T cells: both patients with endometriosis and controls presented an inverse correlation between peritoneal fluid activated T cells and IL-13 levels, and a direct correlation between peritoneal fluid T cells and IL-12 concentrations. These data seem to suggest that a reciprocal modulation exists between peritoneal fluid cytokines and T lymphocyte subsets in patients with endometriosis.     

T helper (Th)1, Th2, and Th17 interleukin pathways in infertile patients with minimal/mild endometriosis

In the present study, interleukin (IL)-10, IL-12, IL-17, and IL-23 levels were measured in serum and peritoneal fluid of women with minimal or mild endometriosis and compared with levels in controls without endometriosis. Higher IL-23 levels were encountered in the peritoneal fluid of women with endometriosis, suggesting a possible role of this cytokine in these women's infertility.     

Minimal and mild endometriosis. Nd:YAG laser treatment and changes in prostaglandin concentrations in peritoneal fluid

Among many patients, infertility originates with minimal and mild endometriosis. Recently, peritoneal fluid factors have come to be associated with infertility in minimal and mild endometriosis patients, and prostaglandin (PG) is suspected of being one of those factors. We use the Nd:YAG laser for treatment of endometriosis; a total of 52 cases of minimal and mild endometriosis have been treated so far with the laser under laparoscopy in our clinic. At the same time we measured the peritoneal fluid volume and PG concentration in peritoneal fluid. Peritoneal fluid volume and PGE2 concentrations were found to be significantly higher than those in the control group (tubal obstruction patients). Seven of 52 patients received second-look laparoscopy three months after Nd:YAG laser treatment; the PG concentration showed a tendency to decrease in many patients, and the PGE2 concentration turned out to be insignificant. Within one year, 30 patients achieved pregnancy. In minimal and mild endometriosis patients Nd:YAG laser treatment may alter the PG concentration in peritoneal fluid, thereby increasing the change of pregnancy.     

Effect of peritoneal fluid from patients with minimal/mild endometriosis on progesterone release by human granulosa-lutein cells obtained from infertile patients without endometriosis: a pilot study

OBJECTIVE: To evaluate the effect of peritoneal fluid (PF) from women without and with minimal/mild endometriosis on progesterone (P) release by cultured human granulosa-lutein cells obtained from infertile patients without endometriosis submitted to ovarian hyperstimulation for in vitro fertilization (IVF). STUDY DESIGN: A pilot study was performed. Human granulosa-lutein cells, obtained from 11 infertile patients without endometriosis (tubal or male factors of infertility) submitted to ovarian hyperstimulation for IVF, were cultured without PF (basal production) and with increasing volumes of steroid-extracted PF samples from 11 patients with endometriosis and 11 patients without endometriosis. Progesterone (P) levels in the media after 72 h culture were measured by chemoluminescence assay. The non-parametric Mann-Whitney-test was used for statistical analysis. RESULTS: PF from patients without endometriosis stimulated P release in a dose-dependent manner up to the dose of 100 microl/ml (10% concentration) when compared with basal production (without adding PF). P release was similar in cultures stimulated with PF from patients with or without endometriosis at 1% (10 microl/ml) and 5% (50 microl/ml) concentrations. At 10% concentration, there was a non-statistically significant reduction in progesterone release by granulosa cells stimulated with PF from patients with endometriosis. PF from patients with endometriosis significantly reduced P release at 30% concentration (300 microl/ml). CONCLUSIONS: PF stimulates P release by human granulosa-lutein cells in a dose-dependent manner. However, higher concentrations of PF from patients with minimal/mild endometriosis reduce P release, suggesting it contains factors that may compromise ovarian steroidogenesis.     

Association of interleukin-6 and estradiol with hepatocyte growth factor in peritoneal fluid of women with endometriosis

BACKGROUND: Different cytokines and ovarian steroid hormones have been reported to regulate the growth and maintenance of endometriosis. We determined the relationship between peritoneal fluid concentrations of interleukin-6, ovarian steroids and hepatocyte growth factor in different revised American Fertility Society (AFS) staging and morphologic appearances of endometriosis. METHODS: Peritoneal fluid was collected from 30 women with endometriosis and 20 women without endometriosis during laparoscopy, and hepatocyte growth factor, interleukin(IL)-6 and ovarian steroids were measured in peritoneal fluid. The concentrations of hepatocyte growth factor and IL-6 in peritoneal fluid were measured by ELISA, and that of estradiol and progesterone by using the immulyze-enzyme amplified luminescence system. Changes in peritoneal fluid concentrations of hepatocyte growth factor, IL-6, estradiol and progesterone in different stages and morphologic appearances of endometriosis were examined to demonstrate their differences in early and advanced endometriosis. RESULTS: Peritoneal fluid levels of hepatocyte growth factor in women with stage I-II endometriosis were significantly higher than in both women with stage III-IV endometriosis and without endometriosis. A similar significant increase in stage I-II endometriosis was also observed for IL-6 and estradiol. When we divided the women according to different morphologic appearances of endometriosis, we found significantly higher concentrations of hepatocyte growth factor (HGF), IL-6, estradiol and progesterone in women containing red lesions compared with other pigments or without endometriosis. A positive correlation was observed between peritoneal fluid levels of IL-6 and hepatocyte growth factor only but not between other markers. Although estradiol levels in peritoneal fluid showed an increased tendency to elevate in the proliferative phase of endometriosis women, hepatocyte growth factor and progesterone displayed higher concentrations in the secretory phase of the menstrual cycle. After adjusting different variables in peritoneal fluid, multiple analysis of covariance indicated that hepatocyte growth factor levels in peritoneal fluid were independently involved in the red morphologic activity of endometriosis. CONCLUSIONS: Early staging and red color appearance of endometriosis are associated with the elevation in peritoneal fluid concentrations of hepatocyte growth factor, IL-6 and estradiol, demonstrating the combined effect of these cytokines and ovarian steroids in the production of hepatocyte growth factor from endometrial tissues in active endometriosis.