The pain caused by endometriosis is thought to be due to a type of white blood cell called a “macrophage” modified by the disease. Ultimately, this discovery could lead to the development of an alternative treatment to hormonal options.
One in ten women is affected by endometriosis in France, a disease caused by the migration of endometrial tissue outside the uterus. On average, it takes doctors seven years to make a sure diagnosis in the absence of very definite symptoms. In the meantime, patients suffer from urinary and digestive disorders and terrible pain during menstruation and intercourse. Once identified, if the disease can be relieved by painkillers or hormonal treatments, or even by performing surgery, no curative treatment exists.
What’s more, conventional hormone-based treatments are “not ideal” because they target the ovaries and can therefore affect the fertility of patients. Also, researchers are trying to better understand the causes of the disease in order to develop alternative treatments. According to a study published in the FASEB Newspaperendometriotic pain is thought to be caused by a type of white blood cell called a macrophage that has been altered by the disease.
Previous studies had already shown that macrophages play a central role in the development of endometriosis. Immune cells help lesions grow and stimulate the development of their blood supply. More recent research has also revealed that macrophages help nerves grow into lesions. Also, the aim of the study conducted here by the Universities of Warwick and Edinburgh, UK, was to “determine the mechanical role of macrophages in the production of pain associated with endometriosis”.
Targeting modified macrophages to reduce patient pain?
Macrophages modified by endometriosis stimulate the growth and activation of nerve cells by releasing a growth hormone called IGF-1, observed the researchers who worked with mice. In women with endometriosis, the levels of IGF-1 in the tissue of the pelvic cavity are higher and in line with the intensity of their pain, notes the study. In addition, by blocking the cellular receptor for IGF-1 in mice, the “painful behavior of those with endometriosis” was reversed, explain the researchers.
Thus, targeting disease-modified macrophages could be a new way to treat pain caused by endometriosis. “If we could better understand the role of macrophages in endometriosis, then we could distinguish them from healthy macrophages and develop treatments to target them”, concludes Dr Erin Greaves who led the study.
A long and invasive diagnosis
Although very common, endometriosis remains a complicated disease to treat. The diagnosis is long and invasive. In most cases, women must undergo an endoscopy, an operation that involves inserting a camera into the abdominal cavity. Researchers are currently working on the development of a simple menstrual blood test to facilitate diagnosis.
Once the latter is established, most patients are prescribed a continuous pill or an IUD releasing hormones to prevent the onset of menstruation, which is always very painful for them. However, these treatments are fraught with side effects. Besides the fertility issues mentioned above, many sufferers have complained of a drastic drop in their libido.
Finally, in cases where the disease is really too important, a surgical operation can remove the lesions and make the symptoms disappear for a certain period. The decision will be made with regard to what the patient experiences on a daily basis, her history and her desire for pregnancy.
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