Institut Clínic of Gynecology, Obstetrics and Neonatology, Hospital Clínic of Barcelona, Faculty of Medicine, University of Barcelona, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
Laboratory of Dioxins, Deparment of Environmental Chemistry, IDAEA-CSIC, Barcelona, Spain.
Hum Reprod. 2015 May;30(5):1059-68. doi: 10.1093/humrep/dev026. Epub 2015 Mar 4.
Are the levels of biologically active and the most toxic dioxin-like substances in adipose tissue of patients with deep infiltrating endometriosis (DIE) higher than in a control group without endometriosis?
DIE patients have higher levels of dioxins and polychlorinated biphenyls (PCBs) in adipose tissue compared with controls without endometriosis.
Some studies have investigated the levels of dioxin-like substances, in serum samples, in patients with endometriosis, with inconsistent results.
STUDY DESIGN, SIZE, DURATION: Case-control study including two groups of patients. The study group (DIE group) consisted of 30 patients undergoing laparoscopic surgery because of DIE. In all patients, an extensive preoperative work-up was performed including clinical exploration, magnetic resonance imaging (MRI) and transvaginal sonography. All patients with DIE underwent a confirmatory histological study for DIE after surgery. The non-endometriosis control group (control group), included the next consecutive patient undergoing laparoscopic surgery in our center due to adnexal benign gynecological disease (ovarian or tubal procedures other than endometriosis) after each DIE patient, and who did not present any type of endometriosis.
PARTICIPANTS/MATERIALS, SETTING, METHODS: During the surgical procedure 1-2 g of adipose tissue from the omentum were obtained. Dioxin-like substances were analyzed in adipose tissue in DIE patients and controls without endometriosis.
The total toxic equivalence and concentrations of both dioxins and PCBs were significantly higher in patients with DIE in comparison with the control group (P < 0.05), mainly due to the significantly higher values of the two most toxic dioxins (2,3,7,8-tetrachlorodibenzo-p-dioxin [2,3,7,8-TCDD] and 1,2,3,7,8-pentachlorodibenzo-p-dioxin [1,2,3,7,8-PeCDD]) (P < 0.01 for each compound). The levels of furan 2,3,4,7,8-PeCDF were statistically higher in the DIE group compared with controls. Only four congeners of PCBs had toxic equivalence values and concentrations that were statistically higher in patients with DIE, but these included the most toxic and carcinogenic PCB-126 (PCB-114 P < 0.05; PCB-156 P < 0.05; PCB-189 P = 0.04; PCB-126 P < 0.01).
LIMITATIONS, REASONS FOR CAUTION: Since few patients were recruited, the study is only exploratory. Our results need to be confirmed in larger and more heterogeneous population studies since environmental and even genetic factors involved in determining dioxins and PCBs widely vary in different countries. Furthermore, the strict eligibility criteria used may preclude generalization of the results to other populations and the surgery-based sampling frame may induce a selection bias. Finally, adipose tissue was obtained only from the omentum, and not from other adipose tissue of the body.
Our results suggest a potential role of dioxin-like substances in the pathogenesis of DIE. Further studies are warranted to confirm our findings.
STUDY FUNDING/COMPETING INTERESTS: None.
Not applicable.
患有深部浸润型子宫内膜异位症（DIE）的患者的脂肪组织中生物活性和最毒的二恶英样物质的水平是否高于没有子宫内膜异位症的对照组？
与没有子宫内膜异位症的对照组相比，DIE 患者的脂肪组织中二恶英和多氯联苯（PCBs）的水平更高。
一些研究调查了子宫内膜异位症患者血清中二恶英样物质的水平，但结果不一致。
研究设计、大小、持续时间：包括两组患者的病例对照研究。研究组（DIE 组）由 30 名因 DIE 而行腹腔镜手术的患者组成。所有患者均进行了广泛的术前检查，包括临床检查、磁共振成像（MRI）和经阴道超声检查。所有 DIE 患者在手术后均进行了 DIE 的确认性组织学研究。非子宫内膜异位症对照组（对照组）包括在每个 DIE 患者后因附件良性妇科疾病（卵巢或输卵管手术除外子宫内膜异位症）在我们中心接受腹腔镜手术的下一位连续患者，并且没有任何类型的子宫内膜异位症。
参与者/材料、设置、方法：在手术过程中，从网膜中获得 1-2 克脂肪组织。在 DIE 患者和没有子宫内膜异位症的对照组中分析脂肪组织中二恶英样物质。
与对照组相比，DIE 患者的总毒性当量和二恶英和多氯联苯的浓度均显著升高（P <0.05），主要是由于两种最毒的二恶英（2,3,7,8-四氯二苯并-p-二恶英[2,3,7,8-TCDD]和 1,2,3,7,8-五氯二苯并-p-二恶英[1,2,3,7,8-PeCDD]）的浓度显著升高（每种化合物的 P <0.01）。与对照组相比，呋喃 2,3,4,7,8-PeCDF 在 DIE 组中的水平统计学上更高。只有四种多氯联苯同系物的毒性当量值和浓度在 DIE 患者中统计学上更高，但其中包括最毒和致癌的 PCB-126（PCB-114 P <0.05；PCB-156 P <0.05；PCB-189 P = 0.04；PCB-126 P <0.01）。
局限性、谨慎的原因：由于纳入的患者较少，因此该研究仅具有探索性。我们的结果需要在更大和更多样化的人群研究中得到证实，因为不同国家环境甚至遗传因素在决定二恶英和多氯联苯方面差异很大。此外，使用的严格纳入标准可能排除了将结果推广到其他人群的可能性，并且基于手术的抽样框架可能会引起选择偏差。最后，仅从网膜中获得了脂肪组织，而不是从身体的其他脂肪组织中获得。
我们的结果表明二恶英样物质在 DIE 的发病机制中可能起作用。需要进一步的研究来证实我们的发现。
研究资金/利益冲突：无。
不适用。
