Objective: To analyse the aetiopathogenesis and the role of defective 'immunosurveillance' in endometriosis.
Method: Review of studies on the pathogenesis of endometriosis, focusing particularly on novel molecules which express adhesive or proteolytic properties. Hypotheses addressing the role of oxidative stress in endometriosis were also reviewed.
Results: Endometriosis is a multifactorial disease associated with a general inflammatory response aiming to clear the peritoneal cavity from the ectopic endometriotic cells and tissue. Modern theories suggest that this inflammatory response creates an environment that may promote implantation and proliferation due to defective 'immunosurveillance'.
Conclusion: The modern interpretation of the theory of reflux menstruation holds that women destined to develop endometriosis have a deficient immune system, which cannot defend against regurgitated endometrial cells. New findings on genetics, immune modulation, and secreted products of endometriotic lesions of affected women have given insight into the pathogenesis of this disorder and may serve as the background for new treatments of endometriosis-associated pain and infertility.