[1379] Acute Transient Arteriopathy in the Early Phase after the Renal Transplantation

R Ohashi, CE Alpers, KD Smith, RF Nicosia, J Kowalewska. Universtiy of Washington Medical Center, Seattle, WA

Background: Vascular lesions in early phase of renal allografts are key determinants of outcome. While vascular rejection characterized by infiltration of leukocytes in the arterial walls has a well recognized impact on the graft survival, other vascular lesions have not been well characterized and documented in the literature. We identified a subset of patients with biopsies performed in the peritransplant period which showed proliferative arterial endothelial cell lesions of uncertain clinical significance. We correlated these vascular lesions to renal function and pathology.
Design: The study population consisted of renal allograft biopsies accessioned at the University of Washington, Seattle, from 1/1/ 2000 to 8/31/2008. Based on pathology reports and histology, we identified cases with a unique arterial vasculopathy, characterized by endothelial cell prominence in the absence of vasculitis, arterial sclerosis, or hyalinosis.
Results: Out of 2938 renal allograft biopsies, 11 cases (0.4 %, mean age; 47.2 11.36) showed arterial lesions characterized by endothelial cell swelling, lifting, and vacuolization without diagnostic features of vascular rejection. Mean post-transplantation time was 16.6 14.7 days. All cases were deceased donor kidney transplants. Induction immunosuppressive therapy included anti-thymocyte globulin (91%) and mycophenolate (64%). The indication for biopsy in all the cases was elevated serum creatinine level (5.1 4.3 mg/dl). Three (18 %) biopsies showed coexistent acute cellular rejection and 6 (55%) demonstrated acute tubular injury. C4d staining in peritubular capillaries was negative in all cases. Follow up biopsies were done in 8 cases (mean follow-up time; 94.9 90.4 weeks) at which time the arterial endothelial lesions identified at the initial biopsy had completely resolved in all patients. The follow-up serum creatinine level demonstrated a significant decline (1.45 0.62 mg/dl, p < 0.005, mean follow-up time; 107.8 93.9 weeks).
Conclusions: We report an acute arteriopathy occurring in the early phase after the renal transplantation. These lesions are associated with increased serum creatinine level, and are reversible. The pathologic findings and the clinical information indicate that these lesions may represent an acute endothelial injury process that occurs during the peritransplant period, analogous to acute tubular injury.
Category: Kidney (does not include tumors)

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 182, Tuesday Afternoon