Vedolizumab Antagonizes MAdCAM-1-Dependent Human Placental Cytotrophoblast Adhesion and Invasion In Vitro.

BACKGROUND

Anti-α4β7 (Vedolizumab) treats inflammatory bowel disease (IBD) by blocking the interaction between integrin α4β7 on leukocytes and mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) on the gut endothelium. Women with IBD often require continuing biologic therapy during pregnancy to avoid disease flare. To date, there have been no reports of an increase in adverse events with Vedolizumab use during pregnancy. Notably, integrins play a major role in human placental development during pregnancy. It is unknown whether Vedolizumab disrupts placental cell (cytotrophoblast) invasion and/or adhesion by blocking interactions with MAdCAM-1. We therefore investigated human placental expression of MAdCAM-1, the role of MAdCAM-1/α4β7 interactions in cytotrophoblast invasion/adhesion in vitro, and whether Vedolizumab administration in vivo alters the placental structure.

METHODS

Histological sections of placentas from normal pregnancies were evaluated for MAdCAM-1 expression by immunofluorescence. The impacts of Vedolizumab or anti-integrin β7 on human cytotrophoblast invasion and adhesion were assessed. Histology results from term placentas of 2 patients with IBD receiving Vedolizumab were compared to those of untreated healthy controls.

RESULTS

Placental MAdCAM-1 expression was predominantly associated with invading extravillous cytotrophoblasts at the maternal-fetal interface. Treatment of isolated primary cytotrophoblasts with Vedolizumab or anti-integrin β7 significantly reduced Matrigel invasion, adherence to a MAdCAM-1-coated substrate, and interactions with HuT-78 cells. Placentas from 2 Vedolizumab-treated patients with IBD exhibited pronounced pathologic features as compared to healthy control specimens.

CONCLUSIONS

This study revealed a previously unrecognized role for α4β7 and MAdCAM-1 in human placentation. More clinical and histological data from Vedolizumab-treated pregnant patients will be necessary to determine whether this medication poses any risk to the mother and fetus.