Distinct Suppression of Prednisone on Endometrial Immune Cells in Women With Reproductive Failure.

RESEARCH QUESTION: For women with reproductive failure, prednisone is widely used but remains controversial as a therapy for improving clinical outcomes. This study aimed to investigate the impact of prednisone on various endometrial immune cells. DESIGN: A total of 24 women with repeated implantation failure and recurrent miscarriage underwent their first endometrial biopsy precisely 7 days after luteinizing hormone surge (LH surge +7). Prednisone was administered from the first day of the subsequent menstrual cycle, followed by the second endometrial sampling on day LH surge +7 again. The density and cell-cell clustering of CD3-CD56+CD16- NK cells, CD3-CD56+CD16+ NK cells, CD68+CD16- macrophages, CD68+CD16+ macrophages, CD3+CD56- T cells, and CD3+CD56+ NK-T cells were analyzed by multiplex staining and compared before and after prednisone treatment. RESULTS: Following prednisone treatment, a significant decrease in the percentage of CD3-CD56+CD16- NK cells (p < 0.001), CD68+CD16- macrophages (p = 0.007), and their clustering degree (p = 0.038) was observed. No significant changes were noted in CD3-CD56+CD16+ NK cells, CD68+CD16+ macrophages, CD3+CD56- T cells, CD3+CD56+ NK-T cells, and their cell-cell clustering. CONCLUSION: Prednisone does not generally reduce all endometrial immune cells; instead, it selectively suppresses specific immune cell subtypes in women with reproductive failure.