Expression of interleukin-11 receptor α and interleukin-11 protein in the endometrium of normal fertile women and women with recurrent miscarriage

Interleukin-11 (IL-11) is a member of the IL-6 family of cytokines. Previous studies have suggested that IL-11 may play a role in human endometrial function. In this study, we have used immunocytochemistry to compare endometrial IL-11Ralpha and IL-11 expression in precisely timed peri-implantation biopsies from 9 normal fertile women and 16 recurrent miscarriage (RM) women. lmmunocytochemistry was semi-quantified by obtaining an H-score value, which showed increased expression of both IL-11 and IL-11Ralpha in epithelial cells compared to stromal cells in all biopsies. There was a significant (P < 0.01) reduction in epithelial cell IL-11. but not stromal cell IL-11, expression in endometrium from RM women compared to normal fertile women. There were no significant differences in expression of IL-11Ralpha protein in both stromal and epithelial cells in endometrium from the two groups of women. This work shows the presence of IL-11 and IL-11Ralpha within the endometrium of RM women during. the peri-implantation period. The decreased expression of IL-11 in epithetial endometrium in RM women suggests that this cytokine may play a role in preventing miscarriage. (C) 2004 Elsevier Ireland Ltd. All rights reserved.