Endometriosis IS an Autoimmune disease.

Endometriosis is a disorder in which tissue normally found inside the uterus begins to grow elsewhere in the body. Endometriosis affects 10–20% of women of reproductive age and is associated with pelvic pain and infertility,

In 1984, Syracuse researchers first noted various immune phenomena including changes in complement levels in women with infertility caused by endometriosis. However, without the advanced analytical methods available today, they were unable to demonstrate the presence of endometrial autoantibodies.

The Autoimmune Link

A large study published in Human Reproduction in 2002 confirmed these early reports. Specifically, women with endometriosis were found to be more than 100 times as likely to have chronic fatigue syndrome as women in the normal population. Hypothyroidism was seven times more common than seen in the normal population and fibromyalgia twice as common.

Women with endometriosis also had higher than expected rates of autoimmune inflammatory diseases including systemic lupus erythematosus, Sjögren’s syndrome, and rheumatoid arthritis, as well as multiple sclerosis. Allergies occurred in 61 percent of patients compared to the 18 percent seen in the normal population. Asthma occurred in 12 percent of the patients compared to the 5 percent seen in the normal population. Among the patients who had chronic fatigue syndrome or fibromyalgia, up to 88 percent had allergies.

Pain Dysregulation Syndromes

Because chronic fatigue syndrome and fibromyalgia are considered to be associated with dysregulation of pain, the researchers proposed that endometriosis might also be associated with abnormal sensitivity to pain. Symptoms that may precede the development of endometriosis include fever, headaches, stiffness and joint problems. Other research recently found that a woman has more than five times the normal risk of getting endometriosis if she has a sister with the disease.

Autoimmune Nature

In 2007, researchers at National Jewish Hospital in Denver discovered that endometriosis lesions are characterized by the presence of abundant plasma cells, many of which produce IgM, and macrophages that produce BLyS/BAFF/TNFSF13B, a member of the TNF superfamily implicated in other autoimmune diseases. In addition, B lymphocyte stimulator (BLyS) protein was found to be elevated in the serum of endometriosis patients. These observations suggest that endometriosis occurs when BLyS-responsive plasma cells interact with retrograde menstrual tissues to give rise to endometriosis lesions.

Endometrial Autoantibodies

In June 2008, researchers at the Indian Council of Medical Research found the presence of antibodies to endometrial stroma in 60 percent of patients with endometriosis. Researchers propose that these anti-endometrial antibodies might be partially responsible for failure of implantation leading to infertility.

The observations made by researchers at National Jewish Hospital along with the demonstration of endometrial antibodies in patients with endometriosis confirm the autoimmune nature of endometriosis.

Resources:

Ninet Sinaii, S. Cleary, M. Ballweg, L. Nieman, and P. Stratton, “High rates of autoimmune and endocrine disorders, fibromyalgia, chronic fatigue syndrome and atopic diseases among women with endometriosis: a survey analysis” Hum Reprod. 2002;17(10):2715-2724

Gajbhiye R, Suryawanshi A, Khan S, Meherji P, Warty N, Raut V, Chehna N, Khole V, “Multiple endometrial antigens are targeted in autoimmune endometriosis,” Reproductive Medicine Online. 2008 Jun;16(6):817-24.