Diagnosing endometriosis accurately - without surgery
A quick, accurate and non-invasive test for endometriosis is being developed by two separate research teams from Australia and Jordan, and Belgium and Hungary. Two studies published in the journal Human Reproduction show that it is possible to diagnose the condition accurately without resorting to a surgical procedure. Endometriosis is a disease affecting the lining of the uterus. It is often quite painful and associated with infertility. Between 10% and 15% of women of reproductive age suffer from this condition, but for several reasons accurate diagnosis - which could lead to effective treatment - is delayed for several years. Laparoscopy is the 'gold-standard' diagnostic technique; however it is a surgical procedure with rare but serious, potential complications. Imaging methods are effective for women with moderate or severe endometriosis, but for those with minimal or mild endometriosis a non-invasive or minimally invasive procedure is urgently needed. Previous studies by researchers in Australia and Jordan demonstrated that there is a far higher density of nerve fibres in the endometrium (uterine lining) of women with endometriosis than in women who do not have the disease. Indeed, the same researchers found that such nerve density was not associated with any other conditions. The preliminary findings inspired a new search for a non- or minimally invasive diagnostic tool. A team led by Thomas D'Hooghe of the University of Leuven in Belgium carefully analysed biobank samples of endometrial tissue taken from 20 women with minimal or mild endometriosis (confirmed by laparoscopy and biopsy), and compared the findings with 20 normal samples. In all cases, the samples had been taken from women during the secretory phase of their menstrual cycle, when the endometrium is maintained and nerve-fibre density is supposedly at its peak. The researchers found evidence of four types of nerve fibres in 90% of the women with endometriosis; importantly, they observed that the fibres are not uniformly distributed throughout the lining. Examining the whole surface of the specimens was an important part of the study design, as looking at randomly chosen fields could give an entirely different result. 'The density varied throughout the samples, with few specimens showing counts above 30 per square millimetre [mm2], and with most between 0 and 10 per mm2. None, or very few, nerve fibres were detected in any of the samples from women without endometriosis,' explained co-author Attila Bokor of the University of Leuven. 'The density of the small nerve fibres was about 14 times higher in endometrium from patients with minimal to mild endometriosis when compared with women with a normal pelvis.' 'Our data show that the combination of three different neural markers increases the sensitivity, specificity and diagnostic accuracy of this method of testing for endometriosis,' added Professor D'Hooghe. 'The test diagnosed endometriosis with 95% sensitivity and 100% specificity.' The researchers believe that pending further population studies, their diagnostic method, which involves the use of autostainers for microscopic analysis, automated immunohistological image analysis and a robust statistical tool, 'can be developed into a valuable and relatively simple tool for the clinical diagnosis of minimal-mild endometriosis'. The Belgian-Hungarian team will carry out a blinded validation study this autumn. 'If this confirms our findings, we believe our research can be a solid base for a simple, reliable and relatively cheap method for non-invasive diagnosis of minimal and mild endometriosis, since transcervical endometrium sampling and immunohistochemical analysis are routine gynaecological and pathological procedures,' Professor D'Hooge concluded.
Countries
Australia, Belgium, Hungary, Jordan