Is Endometriosis an Autoimmune Disease?|Endometriosis Increases the Risk of Cancer & Other Cardiovascular Conditions?
A chronic condition affecting one in every ten women, endometriosis occurs when the lining of the uterus starts to grow in other areas of the body such as the ovaries, the fallopian tubes, and can even reach the bowel or vagina. Under normal circumstances, the lining of the uterus thickens throughout the month and then is shed from your body during the menstrual cycle. However, the displaced endometrial tissue that is growing in other parts also sheds every month but is unable to exit the body and becomes trapped. This displaced tissue can become inflamed and bleeds, causing severe irritation to the organs and cells around them. This is why women suffering from endometriosis often have severely painful periods and may also bleed between periods.
They also tend to suffer from back and pelvic pain. The condition affects women between the ages of 15 and 44 and is most common in women between the ages of 30 - 40 years. There is a change visible in the treatment of endometriosis recently as there is growing evidence that the condition is actually an autoimmune condition and not just a hormonal one. Experts are now of the opinion that there is an autoimmune connection to why some women get affected by endometriosis and others don't.
What is Endometriosis?
Affecting one out of every ten women, endometriosis occurs when the tissue that lines the uterus, known as endometrial tissue, starts to grow outside of the uterus in other parts of the body. It can start to grow on the ovaries, the fallopian tubes, bladder, and even the intestines. The endometrial tissue is what is associated with a woman's menstrual cycle and women suffering from endometriosis therefore end up having severely painful and heavy periods. They also experience pelvic pain and cramps, and can even have painful intercourse. Endometriosis is one of the leading causes of infertility and has been linked to other health concerns as well. In fact, it has been associated with certain autoimmune diseases, fibroids, interstitial cystitis, adenomyosis, and even some types of cancers.
Due to the displaced growth of the endometrial tissues, organs and cells surrounding the tissue can become irritated as the tissue becomes inflamed and bleeds. As there is no way for this tissue to exit the body, it causes irritation and pain at various places where the tissue is growing. The exact cause of endometriosis remains poorly understood and researchers have believed that there are several different causes of endometriosis. Doctors still remain unsure about what exactly triggers this condition. New research, however, now believes that endometriosis could be caused by a combination of factors such as genetics and immune dysfunction, placing endometriosis in the category of autoimmune diseases.
Is Endometriosis an Autoimmune Disease?
Up until now, the clinical approach to the treatment of endometriosis was surgery followed by hormonal suppression medications which were usually hormonal birth control or other similar drugs. Now, however, there is a change happening in endometriosis treatment. The new approach is shifting towards anti-inflammatory and immune-modulating treatments. This is thanks to the fact that there is growing evidence pointing to the fact that endometriosis might not primarily be a hormonal condition, but instead, it is an autoimmune condition.
While endometriosis has still not been officially declared as being an autoimmune condition, research is fast suggesting this fact.
In 2012, a paper titled "Is there an association between autoimmunity and endometriosis?" was released. The authors of this literature review explored the autoimmune connection in detail. The paper concluded that endometriosis fulfills most of the classification criteria that define an autoimmune disease, such as tissue-specific antibodies and blood markers of inflammatory cytokines.
The paper further showed that endometriosis frequently also occurs in combination with other autoimmune conditions such as rheumatoid arthritis, SLE, inflammatory bowel disease and autoimmune thyroid disease.
While the evidence is just falling short of saying that endometriosis is an autoimmune disease, what is clear from recent studies is that there is definitely a complex interplay between the body's defense mechanism for preventing the endometrial cells from implanting outside of the uterus and causing inflammatory lesions. However, the exact role played by the immune systems in this process is still unknown. So while endometriosis has not yet been classified as an autoimmune disease, the evidence is mounting that it does increase your risk for other autoimmune disorders. Experts believe that it is the inflammatory nature of endometriosis that triggers an imbalance in the immune system, giving rise to other autoimmune disorders.
Endometriosis and Other Autoimmune Disorders
Researchers continue to explore and understand what the root cause of endometriosis is. It is now being believed that women suffering from endometriosis could be having abnormal immune system responses stemming from endometriosis or endometriosis could be the result of such responses.
Hypothyroidism, rheumatoid arthritis, fibromyalgia, etc., are all autoimmune disorders and have been linked to having a higher occurrence rate in women having endometriosis. Inflammation is believed to play a role in these conditions, similar to endometriosis.
Other autoimmune disorders linked to endometriosis are celiac disease and inflammatory bowel syndrome (IBS). Both these inflammatory conditions have an established connection to endometriosis.
There are many other autoimmune disorders that have been linked to endometriosis in ways apart from the inflammation factor as well. However, statistics are not very clear on this. Let us take the example of multiple sclerosis and systemic lupus. These two conditions are often identified as autoimmune disorders that have a higher occurrence rate in women with endometriosis, though a study has shown that we cannot conclusively prove that the connection with endometriosis exists.
Endometriosis Increases the Risk of Cancer
It is true that while we won't know for certain whether endometriosis is an autoimmune disorder, the condition definitely increases the risk of certain types of cancer. These include the following.
Ovarian Cancer: The risk for a woman to develop ovarian cancer in her life remains quite low. However, endometriosis is known to increase the chances of being diagnosed with ovarian cancer. While most endometriosis lesions are benign, they can become cancerous due to estrogen levels, oxidative stress, and other factors.
Skin Cancer: There have been 12 studies done that explore the link between endometriosis and skin cancer. Seven out of these 12 studies clearly found that women having endometriosis have a higher risk of getting skin cancer. The remaining five studies could not demonstrate a clear link. It is believed from the results of these studies that exposure to environmental toxins and chemicals can trigger both skin cancer and endometriosis in women, thus connecting the two conditions.
Cervical Cancer: Opposite of the belief that endometriosis heights the risk of cancer, research has suggested that women having endometriosis are actually at a decreased risk of cervical cancer. The exact cause of why this happens remains unknown.
Other Cancers: Studies have also been conducted on brain cancer, endocrine cancer, kidney cancer, and non-Hodgkin's lymphoma to determine if there is a connection to endometriosis, but the results have been mixed. While some studies show the presence of a strong link between endometriosis and these cancers, others claim that there is not sufficient evidence to prove a link. As of now, more research is still needed to understand if there is a link between endometriosis and these other types of cancer.
Endometriosis Increases the Risk of Cardiovascular Conditions
There seems to be a shared genetic background between endometriosis and coronary artery disease. Oxidative stress is believed to be related to both these conditions and it implies that the conditions are linked. In fact, surgeries that are used for treating endometriosis, such as hysterectomies, are also used to treat heart disease.
Treating Endometriosis with Autoimmune Drugs
Studies that have been done with existing drugs such as anti-TNF and pentoxifylline have shown no change in the symptoms of endometriosis. Experts agree that since hormones are the primary driving factor in endometriosis and changes in hormones are successful in treating endometriosis, any autoimmune treatment that is designed in the future will have to be compared with these hormonal therapies for side effects and for determining their final impact on the symptoms of endometriosis. Such kind of a study is yet to be undertaken.
It is important, though, to keep in mind that unlike some of the other autoimmune disorders, endometriosis does not have a measurable autoantibody and also is not known to respond positively to any of the known treatments for autoimmunity.
There are also some other comorbidities that are being suspected to come with endometriosis. Research is still trying to understand more about how these disorders link together with endometriosis. For example, it is believed that vaginal infections and upper respiratory infections are also likely to occur more frequently when you have endometriosis.
To sum up, while many studies are suspecting that endometriosis is an autoimmune disease, there is still no clear evidence to suggest that it has an autoimmune basis as there is no auto antibody that can be identified and the lack of response to the existing autoimmunity treatments have not shown any improvement in endometriosis. This also indicates that drugs such as steroids (prednisone) and methotrexate that have been used for treating autoimmune diseases will not prove to be beneficial to women having endometriosis. While research is still ongoing in the field of endometriosis, it still remains to be determined what the exact role the immune system has on and with endometriosis.