In-vitro endometrial secretion of human interleukin for DA cells/leukaemia inhibitory factor by explant cultures from fertile and infertile women.

Human interleukin for DA cells/leukaemia inhibitory factor (HILDA/LIF) is a cytokine with pleiotropic effects involved in successful murine implantation. We evaluated human uterine HILDA/LIF production by monitoring its in-vitro secretion by endometrial explant cultures obtained from individuals in either normal or pathological conditions. The cytokine secretion was standardized using the day 5:day 1 ratio of HILDA/LIF concentration in supernatants of such cultures, hereby termed HILDA/LIF production index (HLPI). Our results confirmed that HILDA/LIF is secreted by the human endometrium as assessed by secretion at every phase of the cycle in either normal fertile women, or women bearing intrauterine devices. This was also the case for samples obtained from infertile women presenting repeated failures of embryonic implantation or unexplained primary sterility. However, the HLPI were significantly lower in those latter two groups when compared to fertile women. These results suggest an abnormal regulation of HILDA/LIF secretion in such circumstances, and the clinical implication of those data is discussed.