Female patients with no known uterine pathologies and good general health undergoing treatment for unexplained infertility will be identified and invited to participate in the study. Endometrial biopsy will be obtained seven days after luteinizing hormone (LH) surge during a natural cycle. The following month, 5 days after LH surge, peripheral blood mononuclear cells (PBMC) will be isolated from patients' peripheral blood by density gradient (1.077g/ml) centrifugation and suspended in culture medium. The obtained PBMC will be incubated with 500 IU IFNt at 37˚C for 24 hours. This cell suspension will be carefully introduced in the uterine cavity by catheter on day 6 post LH surge. A second biopsy will be obtained the following day (LH+7).~Immunohistochemistry evaluation of endometrial tissue will be performed in terms of quantities and spatial distribution of various cell types.
The aim of this clinical trial is to investigate the change in endometrial composition during the window of implantation following intrauterine administration of PBMC immunomodulated with IFNt.~Patients seeking assisted reproductive therapy will be invited to participate. Two endometrial biopsies will be obtained from each patient during mid-secretory phase of two consecutive menstrual cycles. The first biopsy will be obtained one month before the intervention, and the second one - a day after intrauterine administration of the tested cell treatment which will take place the following month.~Immunohistochemistry analysis of the cell composition of the endometrium will be performed.