Severe Phlebitis Accompanying Vascular Rejection Type Acute T Cell-Mediated Rejection in Renal Transplantation.

PURPOSE: Renal transplant patients with vascular rejection type acute T cell-mediated rejection (ATCMR) grade II have a poor prognosis. Vascular lesions in those cases are thought to randomly occur, thus we searched for a novel pathological marker related to vascular rejection in kidney transplantation. METHODS: We determined pathological characteristics in 14 ATCMR grade II patients treated during an acute phase from 2004 to 2013. We then examined whether those findings appeared in transplant kidney biopsy specimens, except for cases of vascular rejection, in patients examined from 2010 to 2014. RESULTS: In 9 of the 14 ATCMR grade II patients, phlebitis was accompanied by inflammatory cells that formed polypoid projections in the venous lumen and partial disappearance of vascular endothelium. Further investigation showed those inflammatory cells to be T cells and macrophages. Histological findings revealed coexisting phlebitis in 2 of 13 patients with ATCMR grade I, 3 of 24 with borderline changes, and none with normal findings. Phlebitis occurred at a significantly greater rate than the other findings in cases of vascular rejection (P < .05). However, there was no significant difference in regard to graft survival between patients with and without phlebitis (P = .1829). CONCLUSION: Our results suggest severe phlebitis as a novel finding associated with the pathology of vascular rejection in patients with a renal allograft.