Circulating plasma microRNAs as potential non-invasive biomarkers in infertile women with adenomyosis: an observational study.

backgroundDespite advancements in imaging techniques, the non-invasive diagnosis of adenomyosis remains particularly challenging due to the overlap of imaging features with other uterine diseases, and the lack of consistent correlation with clinical presentation, with histological confirmation after hysterectomy still necessary. In this context, circulating miRNAs emerge as promising candidates for accurate non-invasive diagnosis.

methodsTo determine whether women with adenomyosis exhibit a distinct circulating plasma miRNA profile that can serve as a diagnostic marker, miRNA sequencing was performed to compare the plasma miRNA profile of women with adenomyosis with infertile and healthy fertile controls (n =  10/group). Adenomyosis was diagnosed by transvaginal ultrasound using Morphological Uterus Sonographic Assessment (MUSA) criteria. Plasma and endometrial biopsies were collected during the secretory phase from women undergoing hormone replacement therapy. Total RNA was extracted from plasma, libraries were prepared using NEXTFLEX® Small RNA-Seq v4 kits, and miRNAseq was performed on the NextSeq 550 NGS platform. Differentially expressed (DE) miRNAs were identified using the edgeR method (false discovery rate < 0.05). The discriminatory potential of DEmiRNAs was evaluated by receiver operating characteristic (ROC) curve analysis using the area under the curve (AUC). Validation was performed by quantitative PCR on plasma and endometrium (n =  15/group). The target genes of DEmiRNAs were retrieved from miRTarBase and subjected to functional enrichment analysis.

resultsA total of 11 disease-specific DEmiRNAs were identified in adenomyosis compared to infertile controls (5 up- and 6 downregulated), and 23 healthy control-referenced DEmiRNAs compared to fertile controls (19 up- and 4 downregulated). Among disease-specific DEmiRNAs, miR-4433 and miR-652-5p demonstrated strong diagnostic performance for adenomyosis compared to infertile controls (AUC = 0.92 and 0.91, respectively; p < 0.001). For healthy control-referenced DEmiRNAs, 11 miRNAs showed statistically significant diagnostic value (p < 0.01), with the highest AUCs observed for miR-3200-5p, miR-193b-5p, and miR-4732-5p (AUC = 0.88, 0.88 and 0.87, respectively). Validation experiments corroborated the upregulation of miR-4433 and miR-92a-3p upregulation in plasma and endometrium.

conclusionsThis study supports the potential of circulating miRNAs as non-invasive biomarkers for adenomyosis and contributes to understanding its molecular basis. The concordance between circulating and endometrial miRNA expression suggests a possible link between systemic molecular alterations and endometrial pathology.