Runing Title: L-selectin ligands expression in ectopic pregnancy

The objective of the study was to evaluate the expression of L-selectin ligands in the tubal epithelia during tubal ectopic pregnancy. Sixteen Fallopian tube samples from ectopic pregnancies and four normal control Fallopian tubes from women undergoing sterilization were obtained for the study. Oviduct tissues from ectopic pregnancies were separated into implantation sites and matched non-implantation sites. Expression of L-selectin ligands was evaluated by immunohistochemistry with antibodies against HECA-452 and MECA-79 and by real-time polymerase chain reaction. Immunoreactivities against HECA-452 and MECA-79 were significantly higher at the implantation site than at the paired non-implantation site or at the normal oviducts. Moreover, compared with MECA-79, stronger HECA-452 staining was observed in the implantation and non-implantation groups. HECA-452 histologic scores at implantation sites correlated with the serum hCG levels. Increased expression of L-selectin ligands might be involved in the implantation process in tubal pregnancy.