P–346 Luteal endometrial immunity and implantation rates
Authors: Matsumoto L , Imperia. Carneir. Liez F , Miyadahira E H , Turco E L , Oliveir. Ramos F , Heirinch V 
Published: August 2021

Abstract

Study question
Does the percentage of CD56 + NK cells, CD 156 + D16 +, and the presence of CD 138 correlate with pregnancy rates?

Summary answer
Presence of CD 138, as a marker of chronic endometritis, correlates with implantation failure in patients submitted to endometrial immunological analysis despite being treated.

What is known already
Embryo-uterine cross-talk during implantation is a complex process, which involves the synchronization between hormonal aspects, changes in the endometrium, morphological and molecular embryonic quality, and immunological aspects of the endometrium.The presence of CD 138 has been used as a marker of chronic endometritis, which is associated with lower rates of endometrial implantation since the presence of plasmocytes is believed to lead to an increase in interleukins harmful to embryonic implantation.

Study design, size, duration
Retrospective study, with 85 patients submitted to luteal endometrial biopsy, with the same endometrial preparation performed for embryo transfer, from Jun / 2019 to Oct / 20.

Participants/materials, setting, methods
Patients submitted to endometrial preparation, with estradiol, and endometrial biopsy performed on the fifth day of progesterone use. Immunohistochemistry was performed for CD 138, CD 56+, CD16 +. Patients with CD 138+ were treated with antibiotic therapy. Endometrial preparation performed after adequate treatment, and blastocyst transfer. Exclusion criteria: non-treated hydrosalpinx, endometrial adherences, submucosal fibroids, and endometrial thickness less than 5mm. A chi-square test was used to compare the implantation rate group and the p-value of 5% is considered significant.

Main results and the role of chance
The average age of patients with positive beta hCG was 35.63 years ± 8.00, and among patients with negative beta hCG was 39.31 ± 2.206, with p = 0.093.
The pregnancy rate was 55%, 1 blastocyst embryo was transferred, with 47 patients with positive beta hCG, of these, 10 were biochemical pregnancies, and 5 abortions, with 32 evolutionary pregnancies.
There was no difference between the percentage of NK CD 56+ cells among patients with positive beta hCG, with an average of 9.56% ± 11.65%, and 8.26% ± 7.32% among patients who did not become pregnant. (p = 0.694).
There was also no difference between patients regarding the number of NK CD 16+ cells, with an average of 7% ± 8.01%, in patients with positive beta hCG, and in patients with negative beta hCG, 4% ± 3,48%, ep = 0.174.
16 samples presented CD 138+, were treated with antibiotic therapy, but even so, there was a correlation with negative beta hCG and the presence of CD 138+ with p = 0.049.

Limitations, reasons for caution
A retrospective study with a low sample size.
Wider implications of the findings: More prospective studies are necessary to elucidate the effect of endometrial immunity and the influence of CD 138 on embryonic implantation.

Trial registration number
Not Applicable - Retrospective cohort