Acute vascular rejection: a clinical and morphological study

We analyzed one special type of acute vascular rejection (AVR), defined as fibrous thickening of the arterial intimal layer that leads to early renal failure. Twenty-one patients who presented this histological pattern were studied among 339 transplanted over 4 years. Patients were separated into two groups. Thirteen patients have restained their kidneys (Group A, 61.9%) and 8 have lost their grafts (Group B, 38%). Diagnosis was made on average 430. POD in GA and at 49 degrees POD in GB on the 43rd postoperative day in group A and on the 49th postoperative day in group B (NS). In group A, mean serum creatinine is 2.2 mg/dl and follow-up time is 29 months. Oliguria was much more frequent in group B (75% versus 15.3%, P = 0.01). These patients were submitted to 91 renal biopsies always because of non-function. Typical vascular lesions began at arcuate arteries and progressed, as seen in sequential biopsies, to interlobular arteries and arterioles. When only arcuate arteries were affected, 22.5% of renal losses were seen, but when arcuate plus interlobular arteries were compromised, 72.2% of patients lost their kidneys (P = 0.006). We did not identify any difference in immunofluorescent staining from biopsies with or without vascular rejection, or between groups A and B. We concluded that about 2.3% of our patients lost their kidneys because of this kind of AVR, diagnosed near the 43rd postoperative day. The only clinical predictive sign of poor reversibility was oliguria. The attack on arcuate plus interlobular arteries meant a poor prognosis. Immunofluorescent staining did not have a prognostic value.