Lymphatic neoangiogenesis in renal transplants: a driving force of chronic rejection?

Successful therapy of acute renal transplant rejection causes rapid loss of interstitial inflammatory infiltrate cells. Here we show that massive lymphatic neoangiogenesis in the transplant parenchyma at this time point provides exit routes for lymphocytes and macrophages. This proliferation is driven by macrophages that express the lymphangiotrophic growth factor VEGF-C. However, the newly formed lymphatic vessels presumably also organize the perivascular lymphocytes into immunologically active follicular structures which are involved in the survival of the transplant.