Endometrial expression of IL-1RtI in patients undergoing miscarriage or unsuccessful IVF cycles

This study sought to compare the endometrial expression of interleukin-1 receptor type I in patients with a history of spontaneous recurrent miscarriage and patients with unsuccessful IVF cycles. Eight patients who had undergone two or more consecutive unsuccessful IVF cycles (group I), in which at least one good quality embryo was transferred, and 18 patients with at least three spontaneous late miscarriages (group II) were included in the study. Endometrial and follicular development were evaluated by ultrasonography. Plasma concentrations were evaluated for FSH and prolactin on cycle day 3 and for progesterone on day 7 after ovulation, when an endometrial biopsy was performed; samples were cryopreserved for interleukin-1 receptor type I immunohistochemistry and embedded in paraffin for endometrial dating. Patients with no ovulation or any anomalies in hormone concentrations, uterine cavity or endometrial histology were excluded. Interleukin-1 receptor type I was expressed in the lumenal epithelium of both groups. There was a significant difference (P = 0.0357, two-tailed Fisher's exact test) in the glandular epithelium expression of interleukin-1 receptor type I between groups I (87.5% of patients) and II (38.9% of patients). Endometrial expression of interleukin-1 receptor type I does not seem to be involved in embryo implantation in IVF patients, but may play a role in spontaneous recurrent miscarriage.