Histomorphological assessment of phlebitis in renal allografts.
OBJECTIVE
To evaluate the histomorphological features of veins in normal and transplanted kidneys.


METHODS
Between 1992 and 1997, we semiquantitatively evaluated histomorphological changes in veins in nephrectomy specimens of 29 renal allografts with rejection and in 31 control kidneys. The structure of different segments of renal veins was additionally analyzed.


RESULTS
Small interlobular veins were composed of endothelium and basement membrane, similar to capillaries, while the walls of large interlobular and arcuate veins had smooth muscle cell bundles forming the medial layer, similar to large extrarenal veins. In the control group, only focal mononuclear infiltration around small interlobular veins was found (8/31). In rejected kidney allografts, the veins were frequently infiltrated with inflammatory cells, predominantly T lymphocytes and macrophages (29/29). Other changes included thrombosis (16/29), fibrinoid necrosis (7/29), and sclerosis (9/29), and in one case an intimal lipid deposition.


CONCLUSIONS
This study, performed on whole explanted kidney specimens, revealed that rejection vasculitis often involved extrarenal and intrarenal veins, showing a whole spectrum of histopathological changes similar to those in arteries. Since large intrarenal veins have a muscle wall, we believe that the term "rejection phlebitis" could be used in renal transplant pathology.
Jurcić
Vesna
V
Institute of Pathology, Ljubljana University School of Medicine, Ljubljana, Slovenia.
Jeruc
Jera
J
Marić
Stela
S
Ferluga
Dusan
D
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006084:Graft Rejection / Q000473:pathology*; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010689:Phlebitis / Q000473:pathology*; D012082:Renal Veins / Q000473:pathology*