Distributions of endometrial NK cells, B cells, T cells, and Th2/Tc2 cells fail to predict pregnancy outcome following recurrent abortion

Problem: To evaluate the ability of immunophenotypes of endometrial leukocytes from patients with histories of recurrent abortion to predict outcome of subsequent pregnancy. Methods of study: Seventeen women with two successive spontaneous abortions with normal karyotype in the conceptus and 15 women with male-factor infertility were studied. Subsequent pregnancy outcomes in 17 recurrent abortion patients were noted; 11 had live birth, while six aborted in the first trimester. All of 15 women with male-factor infertility became pregnant after therapy, resulting in live birth in all cases. Endometrium was sampled during the peri-implantation period before subsequent pregnancy. We immunostained paraffin-embedded sections for lymphocyte markers including natural killer (NK) cell markers, CD56 and CD16, a B-cell marker CD20, T-cell markers CD3 and CD8, and a specific T-helper(Th)2 and T-cytotoxic (Tc)2 marker termed 'chemoattractant receptor-homologous molecule expressed on Th2 cells' (CRTH2). Immunoreactive cells for these antigens were counted and positivity ratios to CD45- or CD3-positive cells were calculated. These parameter were compared between 17 patients with histories of recurrent abortion and 15 control women and also compared between 11 patients whose subsequent pregnancy was successful and six patients whose subsequent pregnancy was a failure. Results: Numbers of CD45⁺, CD56⁺, CD16⁺, CD20⁺, CD3⁺, CD8⁺, and CRTH2⁺ cells in recurrent abortion patients resembled those in controls. No significant difference in lymphocyte subset numbers or ratios was noted between patients whose subsequent pregnancy was successful and those who again aborted. Conclusion: We could not predict pregnancy outcome by immunophenotypic analysis of endometrium in women with recurrent abortion.