Could endometriosis be diagnosed with a simple test?

It can take years to get a diagnosis of endometriosis, a debilitating condition where tissue similar to the lining of the womb grows elsewhere in the body, but a new study suggests a quicker alternative could be on the way.

Scientists in Spain have shown that it is possible to isolate specific cells that are an indicator of endometriosis from a menstrual blood sample and could potentially deliver a diagnosis within a few weeks.

The study – now available on the prepress BioRxiv platform – focuses on the isolation and profiling of menstrual blood-derived stem cells (MenSCs), which are believed to be the cells that drive lesion formation in endometriosis, using a technique known as DNA methylation profiling, already used in cancer diagnosis.

The team – from the Hospital Universitario Insular de Gran Canaria and Hospital Clinic Barcelona – identified specific DNA methylation signatures to serve as a diagnostic, based on samples taken from 19 endometriosis patients and 23 controls during menstruation.

Their work is being led by Paris, France-based biotech endogene.bio, which specialises in women's health.

According to the paper, the accuracy of their test was 81% in distinguishing women with and without endometriosis. Moreover, their sampling approach is much simpler than alternatives such as harvesting cells from a patient using a surgical procedure known as a laparoscopy and growing them in culture, which can alter their properties and skew testing results.

Millions of women worldwide live with endometriosis, which causes symptoms like pain and extreme tiredness and, if untreated, can result in organ damage and infertility. Despite being so common, the average time to diagnosis is between seven and 10 years.

There is no cure for the condition, although it can be treated with drugs that provide pain relief, hormonal treatments, and surgery to remove some of the errant tissue. A new combination pill, Gedeon Richter's Ryeqo (relugolix/estradiol/norethisterone), was recently launched as an alternative to injectable hormone treatments.

The hope is that an easier way to sample MenSCs could help research into the pathological processes underlying endometriosis, leading to new targeted therapies, and help clinicians stratify patients according to disease severity to guide treatment and their suitability for clinical trials.

According to endogene.bio, the approach has already resulted in a partnership with Spanish pharma group Exeltis, which sells a range of women's health products, including contraceptives, fertility treatments, and nutritional supplements.

Co-founder and chief executive Dr María Teresa Pérez Zaballos said: "By accessing the molecular signals in menstrual blood, we're unlocking information about endometriosis activity that was previously only available through surgery. "

She added: "Many members of our team are endometriosis patients themselves, myself included. Our firsthand understanding of the diagnostic delays, clinical blind spots, and emotional toll of endometriosis shapes every decision we make, from sample collection design to clinical priorities."

The next step for the project will be to validate the approach using a larger group of patients.