Response to editorial entitled “Biomarkers of endometrial receptivity through a minimally invasive approach”

30 05 2013

To the Editor:

The editorial by Dr. Robert Norman in this issue of Fertility and Sterility (1) succinctly summarizes the various approaches currently used to identify biomarkers of endometrial receptivity toward development of a viable predictive/assessment test for clinical application. As Dr. Norman points out, multiple approaches have been applied to identify candidate biomarkers, including proteomic and lipidomic assessments of uterine aspirate fluid and gene expression profiling of endometrial biopsies. In this editorial, Dr. Norman introduces our paper in which we demonstrate the feasibility of performing genome-wide gene expression profiling on uterine aspirations (2). Using unsupervised hierarchical clustering, we demonstrate that the phase of sampling (LH+2 versus LH+7) affects gene expression more so than individual differences in gene expression between patients. We identified and verified robust differences in expression of 245 genes due to phase of sampling and determined that expression of 53 of these genes efficiently separated our two groups and those of a publically available dataset of gene expression signatures obtained from endometrial biopsy samples. Since LH+2 coincides with a pre-receptive phase and LH+7 coincides with a receptive phase in fertile women, the differentially expressed genes identified in our study encode for candidate biomarkers of endometrial receptivity. This 53-gene list overlaps significantly with those indicated in other studies, including the 238-gene list comprising the endometrial receptivity assay used by Diaz-Gimeno et al. (3) in their algorithm for predicting the receptive period from endometrial biopsy samples. We are excited by the potential of our approach because uterine aspiration is less traumatic to the endometrium than biopsy. Unlike endometrial biopsy, uterine aspiration is compatible with evaluation within an active IVF or natural cycle in which a patient is attempting pregnancy (4, 5), enabling us and other researchers to directly associate altered gene expression with implantation success. This approach will facilitate our future identification of those candidate biomarkers for further development of point-of-care assays for clinical use. While our 53-gene cassette includes several interesting candidate biomarkers, including those encoding secreted products, we do not propose these as a clinical test. Rather, we propose that our approach enables further testing and reduction of this signature to identify those genes most predictive. We agree with Dr. Norman that protein-based assays will be preferable to transcript measurements for clinical assays; however, gene expression data are necessary to direct proteomic discovery assays to improve these approaches. Read the rest of this entry »

It’s time to pay attention to the endometrium, including the nucleolar channel system

29 09 2011

To the Editor:

In the context of the excellent Views and Reviews devoted to the endometrium (1), Dr. Bruce A. Lessey offers a thorough analysis of 186 publications that are of significance to the window of implantation (WOI) (2). We feel this already exhaustive effort needs to be expanded further. Although one histological hallmark of midluteal endometrium – pinopodes (whose significance as markers of endometrial receptivity has been questioned) – is reviewed in detail, another, the nucleolar channel system (NCS), went unmentioned. The presence of NCSs distinctly marks the midluteal phase of human endometrium overlapping with the WOI. Read the rest of this entry »

Endometrial preparation for in vitro maturation treatment

27 10 2009

To the Editor:

We read with great interest the paper published recently by Elizur et al. in the September 2009 edition of Fertility and Sterility (1). The authors compared retrospective data of two different protocols used to perform in vitro maturation treatment (IVM) based on physician preference: only micronized 17β-estradiol (6-12 mg/day) for endometrial preparation or human menopausal gonadotropins (HMG) 150 IU/day to induce both endometrial preparation and mild follicle stimulation. Read the rest of this entry »

Woman’s age and morphologic pattern should be taken into consideration while talking about “thin” endometrium

13 05 2009

To the Editor:

We have read with great interest the excellent study by Miwa et al. (1) and would like to comment on the potential relationship between endometrial thickness, a woman’s age and endometrial morphologic pattern. Read the rest of this entry »