Targeted gene expression profiling for accurate endometrial receptivity testing

Abstract

STUDY QUESTIONHow accurately can a targeted gene expression sequencing assay estimate endometrial receptivity corresponding to the window of implantation? DESIGNEndometrial biopsies (n=175) from healthy fertile volunteers (n=66), polycystic ovarian syndrome (PCOS) patients (n=39), and recurrent implantation failure (RIF) patients (n=44) were collected and sequenced with TAC-seq (Targeted Allele Counting by sequencing) method targeting 68 biomarker genes for endometrial receptivity. The expressional profiles were clustered, and differential expression analysis was performed on the model development group, using 63 endometrial biopsies spanning over proliferative (PE, n=18), early-secretory (ESE, n=18), mid-secretory (MSE, n=17) and late-secretory (LSE, n=10) endometrial phases. A quantitative predictor model was trained on the development group and validated on sequenced samples from healthy women, consisting of 52 paired samples taken from ESE and MSE phases and five LSE phase samples from 31 individuals. Finally, the developed test was applied to 44 MSE phase samples gathered from a study group of patients diagnosed with RIF. RESULTSThe developed assay successfully captures the unique receptivity profile of the endometrium using 68 biomarker genes. When compared to healthy women of the same cycle phase, we did not detect any significant gene expression bias caused by PCOS in PE, ESE, MSE, and LSE samples. In validation samples (n=57), we detected displaced WOI in 1.8% of the samples from fertile women. In the RIF study group, we detected a significantly higher proportion of the samples with shifted WOI than in the validation set of samples from fertile women, 15.9% and 1.8%, respectively. CONCLUSIONSThe developed beREADY screening test enables highly sensitive and dynamic detection of selected transcriptome biomarkers, providing a quantitative and accurate prediction of endometrial receptivity status for personalised embryo transfer.