Increased serum polychlorobiphenyl levels in belgian women with adenomyotic nodules of the rectovaginal septum

FERTILITY AND STERILITY௡ VOL 81, NO 2, FEBRUARY 2004 Copyright ©2004 American Society for Reproductive Medicine Published by Elsevier Inc Printed on acid-free paper in U.S.A Increased serum polychlorobiphenyl levels in Belgian women with adenomyotic nodules of the rectovaginal septum The sum of bulk polychlorobiphenyl levels was significantly higher in women with rectovaginal adenomyosis than in women with endometriosis and controls (Fertil Steril௡ 2004;81:456 – ©2004 by American Society for Reproductive Medicine.) We have clearly demonstrated, by immunohistochemical studies, that peritoneal endometriosis and endometriotic (adenomyotic) nodules of the rectovaginal septum are two different entities with different histopathogeneses (1, 2) While peritoneal endometriosis can be explained by the transplantation theory, deep adenomyotic nodules result from the metaplasia of Muăllerian remnants located in the rectovaginal septum Arguments in favor of a retroperitoneal origin of deep adenomyotic nodules have been extensively detailed (3) In Belgium, the incidence of deep adenomyotic nodules of the rectovaginal septum has significantly increased over the last 10 years (4) Several investigators have proposed that environmental agents with endocrine-disrupting or estrogen-like activity may be involved in the pathogenesis of endometriosis (5) Polychlorinated aromatic hydrocarbons (PCAHs), which are environmentally and biologically stable chemicals, were among the first suspected agents (5) There are two main categories of PCAHs: dioxins and biphenyls Biphenyls (PCBs) consist of coplanar or dioxin-like PCBs and bulk PCBs or non– dioxin-like PCBs There is experimental evidence that dioxins and dioxin-like PCBs can promote the development of endometriosis in primate and rodent models (6) In humans, epidemiological studies could not detect a clear association between exposure to PCAHs and endometriosis The absence of surgical ascertainment of endometriotric disease has, however, been evoked as a possible cause of misclassification that may have obscured a possible association (5, 6) Moreover, existing human studies did not make the distinction between peritoneal endometriosis and deep adenomyotic nodules To further explore the possible relationship between exposure to PCAHs and the occurrence of peritoneal endometriosis and deep adenomyotic nodules, we conducted a large case-control study comparing cases of peritoneal endometriosis, deep adenomyotic nodules, and controls Cases of deep nodular lesions (adenomyosis) were established in patients suffering from pelvic pain, severe dysmenorrhea, and dyspareunia Clinical examination indicated, in all cases, a nodular lesion (2–3 cm in size) situated either in the rectovaginal septum or in the retrocervical space where the vagina is attached In all cases, magnetic resonance imaging and rectal ultrasound confirmed the lesions according to the classification described elsewhere (7) Patients were admitted to the academic hospital for surgical treatment, and histological examination of the excised nodular lesion confirmed the diagnosis of deep adenomyotic (endometriotic) lesions Received January 23, 2003; revised and accepted July 23, 2003 This work was supported by a grant (no 3-4587-01) from the Fonds de la Recherche Scientifique Me´dicale, Belgium Reprint requests: Jacques Donnez, M.D., Ph.D., Avenue Hippocrate 10, UCL 13.00, Woluwe B1200, Belgium (FAX: 3202-764-95-07; E-mail: donnez@gyne.ucl.ac.be) 0015-0282/04/$30.00 doi:10.1016/j.fertnstert.2003 07.011 456 Matched patients with peritoneal endometriosis (minimal or moderate according to the revised American Fertility Society classification) were hospitalized during the same week for surgical treatment of peritoneal endometriosis In this group, the presence of an adenomyotic nodule was formally excluded The control group consisted of women with no clinical suspicion of either disease who were recruited during the same period based on consultations with the same gynecologists who referred the deep adenomyotic nodule cases This group was comprised of fertile women of similar age, without complaints of pelvic pain or dysmenorrhea, and with a normal pelvic examination, a normal vaginal echography, and a CA-125 level Ͻ35 U/mL Even if endometriosis could not be formally excluded in this group because of the absence of laparoscopy, it is reasonable to assume that the prevalence of active endometriosis was Ͻ2% (4) Here we report the results of bulk PCB serum levels measured in a first subset of patients randomly selected from the study population After overnight fasting, a 200-mL sample of blood per patient was collected in a Teruflex BB*D456M bag without anticoagulant and centrifuged within 24 hours Serum was transferred into organic solvent– cleaned glassware and kept frozen (Ϫ20°C) until analysis with isotope-labeled internal standards and high-resolution gas chromatography coupled with high-resolution mass spectrometry PCBs TABLE Characteristics of patients No of patients Serum lipids (mg fat/dL) Age (y) Body mass index (kg/m2) Parity Adenomyosis Endometriosis Control P 10 526 (450–662) 29.0 (24–44) 20.3 (17.9–26.6) 0.3 665 (480–681) 27.0 (22–45) 24.0 (18.4–29.4) 10 543 (423–754) 33.5 (25–39) 23.3 (18.0–31.0) 1.5 45a 42a 25a 03b Note: Values are median (range) unless otherwise specified a Kruskal-Wallis test b Pearson’s ␹2 on categorical data (no child, one child, more than one child) Heilier Rectovaginal adenomyosis and PCBs Fertil Steril 2004 nos 3, 8, 28, 52, 101, 118, 153, 180, 194, 206, and 209, as classified by the International Union of Pure and Applied Chemistry, were analyzed, and results were expressed as ng/g lipid, as recommended by Brown and Lawton (8) The laboratory participated in external quality control programs with excellent scores The protocol of this study was approved by the Ethics Committee of the Catholic University of Louvain, and all patients signed an informed consent form Second, the higher overall level of PCBs observed in Belgium compared with Canada may have allowed us to detect differences between the groups more clearly In a recent report from Belgium (11), serum PCB concentrations were measured in a series of 69 women presenting with infertility; Pauwels and coworkers found no difference between patients with endometriosis and those without (9) The levels of PCBs reported in their study are very close to those we observed in controls and patients with endometriosis The mean age and body mass index (BMI) were not statistically different among the three groups (Kruskal-Wallis; Page ϭ 42 and PBMI ϭ 25) (Table 1) As expected, women with peritoneal endometriosis were less fertile than controls and this was also the case in patients with deep adenomyotic nodules No major difference in nutritional or environmental parameters was detected among the groups (not shown) Overall, the concentrations and the pattern of distribution of PCBs in the serum of these Belgian women were consistent with previous reports (9) PCBs nos 153, 180, and 138 were the most abundant, regardless of the group A significant relationship (rPearson 0.55; Pϭ.003) was found between the total concentration of serum PCBs (ng/g fat) and age, but not BMI or fertility The concentration of PCBs was significantly different among the groups after adjustment for age (30 years) (analysis of variance; Pϭ.024), with an average level in deep adenomyotic nodule patients almost twice that found in controls or patients with peritoneal endometriosis (Fig 1) In their study, however, women with endometriosis or adenomyosis were not clearly distinguished (9) The strength of the present study is the fact that two different clinical entities, i.e., peritoneal endometriosis and deep adenomyotic nodules, were separated This allowed us to detect, despite the limited number of subjects involved in this pilot study, an association between deep adenomyotic nodules and increased PCB serum levels FIGURE Sum of bulk PCB levels (standardized for 30 years of age) in serum of patients with endometriosis or adenomyosis of the rectovaginal septum or controls (mean Ϯ SEM) *Significantly different from controls and endometriosis Breast-feeding contributes to lowering the PCB body burden (10) The absence of increased serum PCB concentrations in patients with peritoneal endometriosis, despite a similar decrease in parity and breast-feeding, allows us to exclude the influence of this factor to explain the finding in women with deep adenomyotic nodules This study is the first to provide a clue to an epidemiological association between exposure to PCBs and gynecological disease In Canada, Lebel and coworkers (11) measured serum PCB levels and organochlorine pesticide concentrations in 136 women who underwent laparoscopy for chronic pelvic pain, infertility, or tubal fulguration; they did not detect any difference between women with and without endometriosis Two factors might contribute to explaining our different findings First, in our study, we clearly separated women with peritoneal endometriosis from those with deep adenomyotic nodules FERTILITY & STERILITY௡ Heilier Rectovaginal adenomyosis and PCBs Fertil Steril 2004 457 At the moment, it cannot be established whether the present association is causal Since PCBs and especially their hydroxylated metabolites have demonstrated estrogenic activity (12), a causal role of PCBs in the disease is plausible It cannot, however, be excluded that the detected difference is a reflection of a stronger association between the disease and dioxins and/or coplanar PCBs (bulk PCBs and dioxin serum levels are usually correlated) Further analyses on a larger series of patients are necessary to explore these hypotheses Acknowledgments: The authors thank R Rousseau, M.Sc., for assistance and Dr V Verougstrate, M.D., for data collection Jean-Franc¸ois Heilier, Pharm.D.a Anh Thi Ha, M.Sc.a Dominique Lison, M.D., Ph.D.a Jacques Donnez, M.D., Ph.D.c Rene´ Tonglet, M.D., Ph.D.b Fabienne Nackers, M.D.b Industrial Toxicology and Occupational Medecine Unit,a and Epidemiology Unit,b Universite´ Catholique de Louvain, Brussels; and Department of Gynaecology,c Universite´ Catholique de Louvain and Cliniques Universitaires StLuc, Brussels, Belgium 458 Heilier et al Correspondence References Donnez J, Nisolle M, Smoes P, Gillet N, Beguin S, Casanas-Roux F Peritoneal endometriosis and “endometriotic” nodules of the rectovaginal septum are two different entities Fertil Steril 1996;66:362–8 Nisolle M, Donnez J Peritoneal endometriosis, ovarian endometriosis, and adenomyotic nodules of the rectovaginal septum are three different entities Fertil Steril 1997;68:585–96 Donnez J, Donnez O, Squifflet J, Nisolle M The concept of “adenomyotic disease of the retroperitoneal space” is born Gynaecol Endosc 2001;10:91–4 Donnez J, Van Langendonckt A, Casanas-Roux F, Van Gossum JP, Pirard C, Jadoul P, et al Current thinking on the pathogenesis of endometriosis Gynecol Obstet Invest 2002;54:52–62 Birnbaum LA, Cummings AM Dioxins and endometriosis: a plausible hypothesis Environ Health Perspect 2002;110:15–21 Rier S, Foster WG Environmental dioxins and endometriosis Toxicol Sci 2002;70:161–70 Squifflet J, Feger C, Donnez J Diagnosis and imaging of adenomyotic disease of the retroperitoneal space Gynecol Obstet Invest 2002;54: 43–51 Brown JF Jr, Lawton RW Polychlorinated biphenyl (PCB) partitioning between adipose tissue and serum Bull Environ Contam Toxicol 1984; 33:277–80 Pauwels A, Schepens PJC, D’Hooghe T, Delbeke L, Dhont M, Brouwer A, et al The risk of endometriosis and exposure to dioxins and polychlorinated biphenyls: a case-control study of infertile women Hum Reprod 2001;16:2050 10 Abraham K, Paăpke O, Gross A, Kordonouri O, Wiegand S, Wahn U, et al Time course of PCDD/PCDF/PCB concentrations in breast-feeding mothers and their infants Chemosphere 1998;37:1731–41 11 Lebel G, Dodin S, Ayotte P, Marcoux S, Ferron LA, Dewailly E Organochlorine exposure and the risk of endometriosis Fertil Steril 1998;69:221–8 12 Layton AC, Sanseverino J, Gregory BW, Easter JP, Sayler GS, Schultz TW In vitro estrogen receptor binding of PCBs: measured activity and detection of hydroxylated metabolites in a recombinant yeast assay Toxicol Appl Pharmacol 2002;180:157–63 Vol 81, No 2, February 2004 ... involved in this pilot study, an association between deep adenomyotic nodules and increased PCB serum levels FIGURE Sum of bulk PCB levels (standardized for 30 years of age) in serum of patients with. .. parameters was detected among the groups (not shown) Overall, the concentrations and the pattern of distribution of PCBs in the serum of these Belgian women were consistent with previous reports (9)... measured in a series of 69 women presenting with infertility; Pauwels and coworkers found no difference between patients with endometriosis and those without (9) The levels of PCBs reported in their