Aims
Endometriosis is a common, painful gynaecological condition affecting an estimated 10% of women, also affecting gender diverse people. Laparoscopic surgery is currently the only method of confirming an endometriosis diagnosis, resulting in a diagnostic delay of around seven years in Aotearoa, highlighting the need for non-invasive diagnostic biomarkers. This study aimed to investigate the feasibility of isolating cervicovaginal fluid EVs collected from cervical brushes (CB) and vaginal swabs (VS) for use as a diagnostic tool for endometriosis.
Methods
After providing informed consent, CB and VS samples in phosphate buffered saline (PBS) were collected from anaesthetised patients undergoing laparoscopic surgery for suspected endometriosis at Wellington Hospital (Wellington, New Zealand). EVs were isolated using size exclusion chromatography (qEV1/70nm) and characterised through transmission electron microscopy (TEM), tunable resistive pulse sensing (TRPS) (qNano Gold, NP200), bicinchoninic acid (BCA) assays and reverse transcription quantitative polymerase chain reaction (RT-qPCR).
Results
EV concentration was higher in CBs compared to VSs, as found by TRPS (n=3). TEM demonstrated the isolated particles had intact vesicular structure. BCA (n=12) and RT-qPCR (n=3) assays found similar amounts of EV protein and miRNA between matched CB and VS samples, with low protein yield but reasonable miRNA levels. Both sample types have potential for further exploratory biomarker investigations.
Conclusion
We have demonstrated a novel and clinically accessible method of isolating reproductive EVs, with EVs successfully isolated from cervical smears and vaginal swabs and the completion of basic EV characterisation. Next steps include analysis of EVs contents to identify potential non-invasive biomarkers.