Saliva Test Can Detect Endometriosis

The ENDO-miRNA study claims to be the first prospective study to report a saliva-based diagnostic miRNA signature for endometriosis. If used in a widely available test, this discovery could contribute to improving early diagnosis of endometriosis by means of a non-invasive tool easily available in any health care system, rather than the more invasive and costly laparoscopy.

"Endometriosis diagnosis constitutes a considerable economic burden for the healthcare system with diagnostic tools often inconclusive with insufficient accuracy," the authors wrote. "We sought to analyze the human miRNAome to define a saliva-based diagnostic miRNA signature for endometriosis."

The authors of the prospective ENDO-miRNA study are based in France, including at the Hopital Tenon, Sorbonne University, Ziwig Health, and Lyon South University Hospital.

For the study, they collected 200 saliva samples from 200 women with chronic pelvic pain suggestive of endometriosis. The samples were collected between January and June of 2021. The study consisted of two parts:

* The identification of a biomarker based on genome-wide miRNA expression profiling by small RNA sequencing using next-generation sequencing (NGS); and

* Development of a saliva-based miRNA diagnostic signature according to expression and accuracy profiling using a Random Forest algorithm.

According to the study, among the 200 patients, 76.5% (n = 153) were diagnosed with endometriosis and 23.5% (n = 47) without (controls). Small RNA-seq of 200 saliva samples yielded about 4642 M raw sequencing reads (from approximately 13.7 M to approximately 39.3 M reads/sample).

Quantification of the filtered reads and identification of known miRNAs yielded approximately 190 M sequences that were mapped to 2561 known miRNAs. Of the 2561 known miRNAs, the feature selection with Random Forest algorithm generated after internally cross validation a saliva signature of endometriosis composed of 109 miRNAs. The respective sensitivity, specificity, and AUC for the diagnostic miRNA signature were 96.7%, 100%, and 98.3%. (See: Bendifallah S, Suisse S, Puchar A, et al. Salivary MicroRNA Signature for Diagnosis of Endometriosis. J Clin Med. 2022;11(3):612. Published 2022 Jan 26. doi:10.3390/jcm11030612.)