Renal transplant rejection is caused by a lymphocyte-rich inflammatory infiltrate that attacks
cortical tubules and endothelial cells. Immunosuppressive therapy reduces the number of
infiltrating cells; however, their exit routes are not known. Here a> 50-fold increase of
lymphatic vessel density over normal kidneys in grafts with nodular mononuclear infiltrates is
demonstrated by immunohistochemistry on human renal transplant biopsie susing
antibodies to the lymphatic endothelial marker protein podoplanin. Nodular infiltrates are …