Vedolizumab Does Not Affect Antibody Secreting Cell Recruitment to the Lactating Mammary Gland of Mothers With Inflammatory Bowel Disease.

Despite a known role for α4ß7 and MAdCAM-1 for the recruitment of antibody secreting cells to the lactating mammary gland, vedolizumab which targets integrin α4ß7 did not lower breastmilk IgA in lactating mothers with IBD receiving the drug. It is likely that antibody secreting cells alternatively employ α4ß1 to arrest on VCAM-1 also expressed by the lactating mammary gland.