Expression of interleukin 6 andtumor necrosis factor alpha in endometriotictissues: An immunohistochemical study

Endometrium is a unique part of the human body that showing structural and functional changes during reproductive period. Endometriosis is a disease that occurs by the settlement of the endometrial tissue outside the normal uterine mucosa such as other tissues and organs of the body. This disease occurs in about 10-15 % of women in reproductive age and incidence of the disease is up to 50 % in patients which suffers from chronic pelvic pain, dysmenorrhea and infertility. Although endometriosis is one of the most investigated disease of gynecology, its pathogenesis is still not clear completely. Retrograd menstruation theory has the feature of being the most widely accepted opinion for explaining the pathogenesis of endometriosis. It is contemplated that the combination of genetic ,hormonal, immunological and environmental factors have influence in the pathogenesis of the disease. Studies in recent years indicates the existence of a relation between inflammatory reactions and pathogenesis of endometriosis. In this context, it is thought that cell population in the peritoneal fluid, major cytokines and other soluble factors are responsible for the implantation and progression of the endometriosis. Cytokines are multifunctional proteins which has a key role in cellular growth and development, tissue repair, homeostasis, tumorigenesis, immunity and hemopoiesis. Tumor necrosis factor alpha (TNF-α) is the most effective proinflammatory cytokine produced in response to tissue injury and chronic inflammation. Interleukin 6 (IL-6) is another cytokine involved in the regulation of inflammation reactiones and immune system, cell differentiation, cell proliferation, hemopoiesis and tumorigenesis. Inspite of the studies done so far shows that TNF-α and IL-6 presence in patient with endometriosis, there was no comparative immunohistochemical studys hows the presence of these cytokines in normal and endometriotic tissue and the distribution in the cell types. In this study it is aimed to investigate TNF-α and IL-6 expressions of normal and endometriotic tissues in the human by immunohistochemical methods. Tissue sections that were examined in this study obtained from tissue biopsies of ectopic endometriums taken from 24 women between the ages of 20-40. Additionally, the tissue sections taken from the normal endometrium obtained from 10 patients without any endometrial dysfunction due to dilation or curettage are also evaluated as a control group. It was observed that TNF-α and IL-6 expressions are at varying levels from weak to moderate in the control groups in surface and glandular epithelium. However there is no evidence of a significant staining of the stromal cells. It is found that TNF-α and IL-6 immunoreactivity is significantly increased in the epithelial cells, stromal cells and macrophages which are in endometriotic tissues when these immunoreactivity rates in control endometrium are compared. Expression of TNF-α and IL-6 are both strong in ectopic endometrial tissues. This situation give rise to the tought of the two cytokines may have the same, parallel effects during the process of pathogenesis and development of the disease. When we evaluated the results together, we achieved the conclusion that bothTNF-α and IL-6 are important cytokines that involved in the pathogenesis of the endometriosis.