Disease Severity- and Hormonal Status-Dependent Alterations of EGF and MIF in the Serum of Endometriosis Patients

Endometriosis is the extrauterine engraftment of endometrium-like tissue, causing chronic pain. Complex sensory–vascular–immune interactions, including growth factors, cytokines, and neuropeptides, are implicated in its pathophysiology, but the mechanisms remain unknown. Here, epidermal growth factor (EGF), vascular endothelial growth factor, interleukins (IL-1β, IL-6, IL-8), macrophage migration inhibitory factor (MIF), calcitonin gene-related peptide, and somatostatin were measured in the serum of endometriosis patients with different disease severities, menstruation cycle- and pharmacotherapy-related hormonal status compared with controls. Mediator levels in deep-infiltrating rectosigmoid nodules were also compared with those in non-endometriotic colon tissues. Pain was assessed by the visual analogue scale. Serum EGF was significantly lower in mild endometriosis and in the secretory phase. MIF and IL-6 were higher in stage I–IV endometriosis, with MIF also higher in the secretory phase and in patients not receiving oral contraceptives. Somatostatin was lower in mild endometriosis than that in healthy individuals and the severe endometriosis group. No tissue-level differences were found. A strong positive correlation between serum EGF and somatostatin levels and dysmenorrhea and dysuria was detected in mild cases. It is concluded that certain serum alterations may be related to severity- and hormone status-dependent endometriosis mechanisms, but their diagnostic/prognostic value seems to be limited due to variability and lack of specificity.