Endometrial nerve fiber density and CA-125 and CD23 levels in the blood can help diagnose women thought to have endometriosis but lacking the most common symptoms, a pilot study suggests. Moreover, these parameters can help monitor endometriosis treatments’ effectiveness.
The study, “Assessment of biomarkers in women with endometriosis-associated pain using the ENG contraceptive implant or the 52 mg LNG-IUS: a non-inferiority randomised clinical trial,” was published in The European Journal of Contraception & Reproductive Health Care.
Diagnosis of endometriosis involves invasive surgery to collect tissue from lesions. In cases of deep endometriosis, clinicians can use non-invasive, image-based diagnostic methods, including magnetic resonance imaging (MRI) and transvaginal ultrasonography (TVUS).
However, in many cases, achieving an early and accurate diagnosis of endometriosis remains a challenge. Identifying biomarkers of endometriosis that can help predict its development and progression is an emerging need.
Researchers at University of Campinas Medical School in Brazil evaluated the diagnostic and predictive potential of CA-125, CD23, and endometrial nerve fiber density.
CA-125 is mostly known for being a biomarker of ovarian cancer, but was also suggested as a biomarker of endometriosis. “Although CA-125 has low sensitivity and specificity, it is still one of the most common biomarkers for managing women with endometriosis,” researchers stated.
CD23 is a protein produced by immune cells during an active inflammatory process, such as that occurring in endometriosis. Increased endometrial nerve fiber density has previously been linked to endometriosis-associated pain.
The study (NCT02480647) included 103 women with confirmed endometriosis-associated pain. They randomly received either Mirena (levonorgestrel-releasing intrauterine system) or Nexplanon (subdermal implant-releasing etonogestrel).
Before treatment, CD23 levels were found to be significantly higher in endometriosis patients as compared to median reported values for healthy women, which suggests CD23 could be a suitable biomarker of endometriosis.
Analysis performed six months after the start of treatment showed that CD23 blood levels and nerve fiber density in endometrial tissue samples were significantly reduced in both treated groups. Also, patients treated with Nexplanon had lower levels of CA-125.
In addition, evaluation of pain symptoms’ severity, as determined by visual analog scale (VAS) scores, showed significant improvement in pelvic-pain and painful-period scores in both treatment groups. Still, the team found no correlation between the biomarkers assessment and the reported improvements in pain symptoms.
“[These] findings could be useful for healthcare professionals when counseling women with endometriosis-associated pain,” researchers said.
Although these biomarkers have not been recommended to help diagnose endometriosis in the most recent guidelines, the team thinks they could “be a complementary, non-invasive diagnostic tool.” They could be particularly useful “for asymptomatic women, adolescents with suspected endometriosis and infertile women with suspected endometriosis but without pain,” they said.