The levels of nitric oxide and asymmetric dimethylarginine in the rat endometriosis model

What We Have Learned from Animal Models to Understand the Etiology and Pathology of Endometrioma-Related Infertility

Endometrioma (OMA) is the most common subtype of endometriosis, in which the endometriotic lesions are implanted in the ovary. Women with OMA are usually associated with infertility, presenting with reduced ovarian reserve, low oocyte quantity and quality, and poor fertility outcomes. However, the underlying pathological mechanisms in OMA-related infertility are still unclear. Due to the limitations and ethical issues of human studies in reproduction, animal models that recapitulate OMA characteristics and its related infertility are critical for mechanistic studies and subsequent drug development, preclinical testing, and clinical trials. This review summarized the investigations of OMA-related infertility based on previous and latest endometrioma models, providing the possible pathogenesis and potential therapeutic targets for further studies.

Endometriosis Classification and The Role of Tumor Necrosis Factor-Alpha Polymorphisms as A Therapeutic Target

In the recent original research published on International Journal of Fertility and Sterility the association between tumor necrosis factor-alpha (TNF-α) genetic polymorphisms and endometriosis in 150 Iranian patients suffered this disease. The authors notably found a lower frequency of TNF-α -863C/A allele A among the affected patients in comparison with healthy women, although this difference was not significant by adjusting multiple testing. We deem that the authors should specify, if these patients had peritoneal nodules, ovarian endometrioma/deep infiltrating endometriosis (DIE) nodules or combination of them, since it has been hypothesized that these phenotypes may represent three distinct pathogenetic entities of endometriosis.

Investigational drugs for the treatment of endometriosis, an update on recent developments

INTRODUCTION

Endometriosis is a hormone-dependent benign chronic disease that requires a chronic medical therapy. Although currently available drugs are efficacious in treating endometriosis-related pain, some women experience partial or no improvement. Moreover, the recurrence of symptoms is expected after discontinuation of the therapies. Currently, new drugs are under intense clinical investigation for the treatment of endometriosis.

AREAS COVERED

This review aims to offer the reader a complete and updated overview on new investigational drugs and early molecular targets for the treatment of endometriosis. The authors describe the pre-clinical and clinical development of these agents.

EXPERT OPINION

Among the drugs under investigation, late clinical trials on gonadotropin-releasing hormone antagonists (GnRH-ant) showed the most promising results for the treatment of endometriosis. Aromatase inhibitors (AIs) are efficacious in treating endometriosis related pain symptoms but they cause significant adverse effects that limit their long-term use. New targets have been identified to produce drugs for the treatment of endometriosis, but the majority of these new compounds have only been investigated in laboratory studies or early clinical trials. Thus, further clinical research is required in order to elucidate their efficacy and safety in human.

Medical Management of Endometriosis

Endometriosis is a chronic medical condition that affects around 6% to 10% of reproductive age women. Pelvic pain, dysmenorrhea, and infertility are the most common presenting symptoms. The disease is characterized by estrogen-dependent growth of the endometrial glands and stroma outside the endometrial cavity. The diagnosis requires a high degree of suspicion and can be only confirmed on histopathology. Treatment includes medical and surgical options. Both hormonal and nonhormonal medical options are available and are tried at first with a goal to control pain and stop the growth of the endometriotic lesions. Nonsteroidal anti-inflammatory drugs, oral contraceptive pills, gonadotropin-releasing hormone (GnRH) agonists, aromatase inhibitors are some of the commonly used medications. With more research on the molecular and biochemical aspects of endometriosis, newer targets of therapy are being developed like selective progesterone receptor modulators, antiangiogenic factors and immunomodulators. In women who do not respond to medical therapy or have severe symptoms, surgical excision of the endometrial lesions and adhesions is often helpful and offers confirmatory diagnosis by histopathology.