The clinical characteristics of women with recurrent implantation failure.

Recurrent implantation failure (RIF) refers to failure to conceive after three or more in vitro fertilisation (IVF) or embryo transfer cycles. Implantation failure may be due to embryo or uterine factors. There are many controversies surrounding the investigation and management of this condition. The aim of our study was to describe the clinical characteristics and the outcome of investigations of a group of women with recurrent implantation failure. A total of 111 couples with RIF were managed in a dedicated clinic and investigated according to a clinic protocol. The frequency of abnormal investigations were as follows: high (≥ 10 IU/l) FSH, 14/107(13%); high free androgen index 6/78(8%); abnormal hysteroscopic findings 7/45(16%); hydrosalpinges 8/33(24%); persistently elevated ACA or tested positive for lupus anticoagulant 19/108 (18%); abnormal karyotype analysis 3/101(3%); hyperprolactinaemia 1/79(1%); abnormal thyroid function 4/100(4%) and tested positive for thyroid peroxidase antibody 10/104(10%). Specific treatments according to the results of investigation produced a live birth rate of 29%. It was concluded that the findings should help practitioners to construct suitable investigation protocols for the initial management of this condition.

The correlation of autoantibodies and uNK cells in women with reproductive failure.

There is conflicting evidence on the role of autoimmune disorders in reproductive failure, including recurrent miscarriage (RM) and recurrent implantation failure (RIF), after in vitro fertilisation (IVF). Several commonly studied autoimmune markers in women with reproductive failure include antiphospholipid antibodies (APAs), thyroid peroxidase antibodies (TPA) and uterine natural killer (uNK) cells. However, there have not been any studies that have examined the correlation of these markers in women with reproductive failure. To determine if women who tested positive for autoantibodies (APA and thyroid peroxidase antibodies) have significantly higher uNK cell numbers than women who tested negative for these antibodies, the percentage of stromal cells that stained positive for CD56 was identified by immunocytochemistry in endometrial biopsies from 42 women with unexplained RM (29 women tested negative for autoantibodies and 13 women tested positive for autoantibodies) and 40 women with unexplained RIF (30 women tested negative for autoantibodies and 10 women tested positive for autoantibodies). Biopsies were obtained on days LH+7 to LH+9. There was no significant difference in uNK cell numbers between women with unexplained RM who tested negative and those who tested positive for autoantibodies. Similarly, there was no significant difference in uNK cell numbers between women with unexplained RIF who tested negative and those who tested positive for autoantibodies. In women with reproductive failure the presence of autoantibodies does not appear to affect the numbers of uNK cells in the endometrium around the time of implantation.

Expression of leukaemia inhibitory factor and interleukin 15 in endometrium of women with recurrent implantation failure after IVF; correlation with the number of endometrial natural killer cells.

BACKGROUND: Several studies have suggested that endometrial interleukin 15 (IL-15) and the leukaemia inhibitory factor (LIF) may be important in embryo implantation. IL-15 is postulated to play a role in the control of uterine natural killer (uNK) cell proliferation and function, and uNK cells are also known to play a role in implantation. The aims of this study was to (1) compare endometrial levels of IL-15 and the LIF in women with recurrent implantation failure (RIF) after IVF with those in fertile women (controls) and (2) examine the relation of IL-15 and LIF levels to the uNK cell number. METHODS: We investigated IL-15 and LIF in precisely timed endometrial biopsies (days LH + 7-LH + 9, where the day of the LH surge is LH + 0) obtained from control women (n = 15) and women with RIF (n = 45) by immunohistochemistry. A semi-quantitative analysis was performed by the H-score analysis of staining intensity in the stroma, glandular epithelium and luminal epithelium, separately. We also correlated expression of LIF and IL15 with uNK cell numbers (obtained in an earlier study of the same samples). RESULTS: The quantity of the LIF protein in endometrial glandular epithelium in women with RIF [median and range; 179 (70-365)] was lower (P = 0.01) than in control women [median and range; 247 (120-287)]. In contrast, the level of the IL-15 protein in the stroma in women with RIF [median and range; 90 (0-175)] was higher (P = 0.009) than in control women [median and range; 60 (15-150)]. There was a significant correlation between the uNK cell number and stromal expression of IL-15 (r = 0.427, P = 0.001). No correlation between the LIF expression in any compartment and the uNK cell number was seen. CONCLUSIONS: The results show an altered expression of LIF and IL-15 in the endometrium of women with RIF. Despite the limitation of not identifying uNK cells by phenotypic markers, the correlation between the uNK cell number and the stromal cell IL-15 suggests that IL-15 may play a role in the control of endometrial uNK cell function or proliferation.

Measurements of CD56+ cells in peripheral blood and endometrium by flow cytometry and immunohistochemical staining in situ.

BACKGROUND: CD56+ cells in peripheral blood or the endometrium may be increased in women with reproductive failure. However, the relationship between numbers of peripheral blood CD56+ and endometrial CD56+ cells is uncertain. The aim of this study was (i) to compare the numbers of CD56+ cells in peripheral blood and endometrium in samples taken simultaneously and (ii) to compare measurements by flow cytometry and immunohistochemistry of CD56+ cells in the same endometrial biopsy. METHOD: Endometrial biopsies and blood were obtained from women with recurrent miscarriage (n= 25) on days LH+7-LH+9 of the cycle. The total number of CD56+, CD56+ CD16- and CD56+CD16+ cells in blood was measured by flow cytometry; the number of CD56+ cells in the endometrium was determined by immunohistochemistry. Endometrial samples were also obtained from fertile women (n= 20) and used to measure CD56+ and CD45+ cells, by both flow cytometry and immunostaining. RESULTS: There was no correlation between the numbers of total CD56+, CD56+CD16- or CD56+CD16+ in peripheral blood and the number of endometrial CD56+ cells in the same women. In endometrium from fertile women, a significant correlation was found between the numbers of CD56+ cells measured by flow cytometry and immunohistochemistry (correlation= 0.497, P= 0.026, when expressed as % total cells; correlation= 0.570, P= 0.009 when expressed as % CD45+ cells). CONCLUSIONS: Measurements of CD56+ cells in peripheral blood do not correlate with endometrial CD56+ cell numbers and therefore should not be extrapolated to events in the endometrium. In contrast, measurements of endometrial CD56+ cells by flow cytometry and immunostaining correlate well.