Engin Oral

Pathogenesis of endometriosis

Endometriosis is a common gynecologic disorder characterized by the presence of endometrial tissue outside the uterine cavity. Various theories have been put forth to explain the mechanisms for the development of this disease. Although no single theory can explain all cases of endometriosis, the retrograde menstruation theory has gained the widest acceptance. This theory proposes that viable endometrial tissue is refluxed through the fallopian tubes during menstruation and implants on peritoneal surface or pelvic organs. Retrograde menstruation occurs in 76% to 90% of women. The much lower prevalence of endometriosis suggests that additional factors determine susceptibility to endometriosis. Once in the peritoneal cavity, the survival and implantation of endometrial cells seem to be mediated by abnormal MMP and TIMP expression, altered immune milieu, aberrant local aromatase activity, and genetic and environmental factors.

The effect of endometriosis on implantation : results from the Yale University in vitro fertilization and embryo transfer program

OBJECTIVE To investigate the effect of endometriosis on implantation. DESIGN Case-control study from Yale University IVF-ET program. PATIENTS Two hundred eighty-four consecutive IVF cycles were analyzed retrospectively. Patients with endometriosis only (n = 35; 89 cycles) were compared with an age-matched control group with tubal infertility (n = 70; 147 cycles) and also to a group with unexplained infertility (n = 15; 48 cycles). Data from the endometriosis group was analyzed further in subgroups of minimal-mild (43 cycles) and moderate-severe (46 cycles). RESULTS No difference was found in the number and the quality of oocytes retrieved and fertilization rates between the endometriosis, the tubal infertility, and the unexplained infertility groups. The quality and the number of embryos transferred in each group were comparable. A trend toward reduced pregnancy rate per transfer (14.8%) in the endometriosis versus tubal or unexplained infertility groups (25.7% and 23.3%, respectively) was observed. Implantation rate (gestational sac per transferred embryo) was significantly lower in the endometriosis versus the tubal infertility group (3.9% versus 8.1%; unexplained infertility group, 7.2%). Analysis of first cycles only across all groups revealed that the implantation rate also was significantly lower in the endometriosis versus the tubal infertility group (3.1% versus 9%; unexplained infertility group, 6.7%). Within the endometriosis group, although the pregnancy rate per cycle and per transfer were similar in subgroups, patients with minimal-mild endometriosis had the lowest implantation rate. CONCLUSION We conclude that, in patients with endometriosis, implantation rate is low. Abnormal implantation, which may be secondary to endometrial dysfunction or embryotoxic environment, is a factor in endometriosis-associated subfertility.

Monocyte chemotactic protein-1 concentration in peritoneal fluid of women with endometriosis and its modulation of expression in mesothelial cells☆

OBJECTIVE To investigate monocyte chemotactic protein-1 concentrations in the peritoneal fluid (PF) of women with or without endometriosis, then assess peritoneal mesothelial cells as a potential source of monocyte chemotactic protein-1. DESIGN Prospective study. SETTING University medical center. PATIENT(S) Women with (n = 60) or without (n = 18) endometriosis. INTERVENTION(S) First monocyte chemotactic protein-1 levels in PF were measured, then mesothelial cells in culture were treated with cytokines. MAIN OUTCOME MEASURE(S) In PF and culture supernatants, monocyte chemotactic protein-1 was measured by ELISA. In vitro monocyte chemotactic protein-1 messenger RNA expression was evaluated by Northern analysis. RESULT(S) The median concentration of monocyte chemotactic protein-1 in PF of control women was 137 pg/mL (conversion factor to SI unit, 0.115; range, 12 to 418 pg/mL); that of women with moderate endometriosis was 205 pg/mL (range 65 to 6,000 pg/mL); and that of those with severe endometriosis was 1,165 pg/mL (0 to 2,602 pg/mL). Within the moderate to severe endometriosis group, monocyte chemotactic protein-1 levels were higher in women with untreated endometriosis (354 pg/mL range 0 to 6,000 pg/mL) than in women receiving GnRH agonist (128 pg/mL, range 0 to 216 pg/mL). In the control group, monocyte chemotactic protein-1 levels were higher in the proliferative phase than in the secretory phase. Mesothelial cells produced constitutively monocyte chemotactic protein-1; moreover, both interleukin-1 alpha and tumor necrosis factor-alpha induced higher levels of monocyte chemotactic protein-1. CONCLUSION(S) Levels of monocyte chemotactic protein-1 in PF were higher during the proliferative phase than secretory phase of control women and increased in moderate to severe endometriosis. The regulated expression of monocyte chemotactic protein-1 may recruit macrophages into PF and contribute to the pathogenesis of endometriosis.

Monocyte chemotactic protein-1 expression in human preovulatory follicles and ovarian cells

There is a considerable population of macrophages (5-15% of the cells) within the human ovarian follicle at the time of ovulation. Macrophages are also present within the ovarian stroma, mostly near perifollicular capillaries. We hypothesized that macrophage migration in and around the preovulatory follicle is hormonally regulated and that regulation of macrophage migration occurs through local modulation of monocyte chemotactic protein-1 (MCP-1) that chemoattracts and activates monocytes/macrophages. In this regard, we investigated the expression and regulation of MCP-1 in human follicular fluid and in ovarian stromal and granulosa-lutein cell cultures. The concentration of MCP-1 in follicular fluid samples obtained from women prior to the administration of hCG was (n = 4) 90 +/- 27 (mean +/- S.E.) pg/ml; in samples obtained 12 h after the hCG administration it was (n = 3) 135 +/- 23 pg/mL; in follicular fluids obtained 34 h after the hCG administration it was (n = 126) 322 +/- 46 pg/mL (P = 0.007 vs. pre-hCG). The mean ratio of follicular fluid/serum MCP-1 levels was 4.18. There was a correlation between follicular fluid MCP-1 levels and follicular fluid or serum progesterone levels (r = 0.21, P = 0.02; r = 0.29, P = 0.03, respectively). MCP-1 mRNA and the protein were expressed in ovarian stromal and granulosalutein cells in culture and were increased by interleukin-1 alpha and tumor necrosis factor-alpha in a time- and concentration-dependent manner. LH/hCG induced higher levels of MCP-1 mRNA expression and protein production in both cell cultures. We propose that regulation of MCP-1 in ovarian stromal and granulosa-lutein cells by cytokines may play a role in the physiology of periovulatory events.

Growth-Regulated α Expression in Human Preovulatory Follicles and Ovarian Cells

PROBLEM: Around the time of ovulation the number of neutrophils increases in the theca of the leading follicle. We hypothesized that growth‐regulated a (GROα), a neutrophil chemoattractant/activating factor, may be a modulator of periovulatory neutrophil chemotaxis.

Growth-regulated α expression in the peritoneal environment with endometriosis

Objective To investigate the presence and modulation of growth-regulated α, a member of the chemokine family with neutrophil chemotactic activity, in the peritoneal fluid of women with or without endometriosis. Methods Peritoneal fluid samples were obtained at laparoscopy from 63 women with endometriosis and 19 fertile women without endometriosis. Endometrial tissue was obtained from uteri after hysterectomy for reasons other than endometrial disease or from endometrial biopsies of reproductive-age women. Cellular RNA was extracted and northern blots were hybridized with an oligonucleotide probe complementary to a specific sequence of growth-regulated α messenger RNA. Growth-regulated α in peritoneal fluid and culture supernatant was quantified using enzyme-linked immunosorbent assay. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney tests. Results The median (range) concentration of growth-regulated α in peritoneal fluid samples from 19 normal fertile women was 27 pg/mL (0-108), from 24 women with moderate endometriosis 34 pg/mL (8–150), and from seven with severe endometriosis was 73 pg/mL (10–221) (P = .04, P = .01, respectively). In the moderate and severe endometriosis groups, the levels of growth-regulated α were significantly higher in the peritoneal fluid of women with untreated endometriosis (73 pg/mL [10–221]) than in women with medically treated endometriosis (25 pg/mL [8–47]). In mesothelial and endometrial stromal cells in culture, growth-regulated α messenger RNA and protein were detectable constitutively; however, both interleukin-1α and tumor necrosis factor-α induced higher levels of growth-regulated α messenger RNA and protein in a dose- and time-dependent manner. Conclusions Growth-regulated α levels are elevated in the peritoneal fluid of women with moderate and severe endometriosis. This chemotactic factor, which acts via the interleukin-8 receptor, may play a role in the pathogenesis of endometriosis.

Peritoneal fluid from women with moderate or severe endometriosis inhibits sperm motility: the role of seminal fluid components**Supported by grants HD-19505 and HD-32902 (to G.H.) from the National Institutes of Health, Bethesda, Maryland.

OBJECTIVE To examine the mechanism of sperm motility inhibition by peritoneal fluid (PF) from women with endometriosis. DESIGN Prospective, randomized study. SETTING University-based andrology laboratory. PATIENTS Women with and without endometriosis. INTERVENTIONS Fresh semen or Percoll-purified sperm fractions were combined with PF from women with endometriosis (n = 20), from fertile women without endometriosis (n = 10), or with physiological saline. MAIN OUTCOME MEASURE Sperm motility parameters were determined with computer assisted semen analysis. Data were evaluated by the analysis of variance and the Students t-test. RESULTS Peritoneal fluid from women with minimal or mild endometriosis did not inhibit sperm motility in semen. Peritoneal fluid from women with moderate or severe endometriosis caused approximately 40%, 50%, and 80% declines in sperm motility and in percent progressive motile sperm after 4,7, and 24 hours, respectively. Sperm velocity was inhibited by approximately 30% and 60% after 7 and 24 hours, respectively. However, in the Percoll-purified sperm fractions the same PF did not inhibit sperm motility within the 4- to 7-hour time frame, and only a 17% to 42% inhibition occurred after the overnight incubation. Sperm velocity was not affected. CONCLUSION Cellular components of seminal fluid appear to mediate the inhibitory action of PF. Assuming that the leukocyte components of semen and PF are common, the cell-mediated inhibition of sperm motility is a likely contributor to endometriosis related infertility.