P-389: Immunohistochemistry confirms the presence of chronic endometritis in patients with recurrent implantation failure

Abstract

We have previously reported that patients with recurrent implantation failure (RIF) have a higher incidence of chronic endometritis in their endometrium. This study was carried out to identify by immunohistochemistry the immunological cells found in the endometrial biopsies diagnosed with chronic endometritis in those patients. Retrospective Comparative Study in a Tertiary Care Center. We reexamined the endometrial biopsies which showed chronic endometritis (n=9) performed on patients who failed at least two consecutive in vitro fertilization and embryo transfer (IVF-ET) cycles and then proceeded with either a fresh IVF-ET or a thaw cycle after the biopsy date (n=25), between 2001-2004. Biopsies were performed using a Pipelle catheter or sharp curettage after confirmation of a negative pregnancy test. Biopsies were evaluated by the same University Pathology Department. Chronic endometritis was defined as presence of plasma cells in the endometrial stroma on H&E stained biopsies. Endometrial biopsies from our previously reported study were immunohistochemically stained with an antibody specific to plasma cells, CD 138, to distinguish them from other immunological cells. Slides were cut from the origin paraffin embedded endometrial biopsies and prepared for immunohistochemical staining by dewaxing and antigen retrieval. Prepared slides were then incubated with the CD 138 antibody, Biocare Inc, at 1:100 dilution for 1 hour. Slides were then washed and incubated with EnvisionPlus-HRP anti-mouse antibody for 30 minutes and developed with DAB+. The population consisted of two groups: Group 1 (n=9) included patients with chronic endometritis, Group 2 (n=17) were patients with negative biopsies. All 9 biopsies previously described as chronic endometritis (Group 1) stained positive with the CD 138 antibody, thus immunohistochemically confirming the diagnosis of chronic endometritis in 34.6% (9/26) of the patients biopsied. All patients had a negative test of cure prior to initiation of their next cycle. Age, number of previous failed cycles, number of transferred embryos and the number of good quality embryos were similar between the two groups. Patients with chronic endometritis had significantly lower clinical pregnancy and implantation rates (11.1% and 8.3%) as compared with those with negative biopsies (58% and 31.1%) respectively (P<0.05). Chronic endometritis was identified in approximately 35% of the patients biopsied. This is significantly higher than previous reports (2-13%), therefore we used immunohistochemical staining to confirm this diagnosis. Clinical pregnancy and implantation rates were significantly lower in patients with chronic endometritis, even after appropriate antibiotic treatment. This pathology may permanently alter the integrity or biochemical milieu within the endometrial cavity. It is also possible that the plasma cells, which are used to diagnose chronic endometritis, are part of another immunologic process taking place within the endometrial cavity. Our study confirms that chronic endometritis is a frequent finding which confers a poorer prognosis for patients with RIF.