Clinicopathologic analysis of acute vascular rejection cases after renal transplantation

Histopathologic change of acute vascular rejection (AVR) is characterized by intimal arteritis and transmural arteritis. In this report, we discuss the clinicopathologic analysis of AVR cases after renal transplantation.

AVR was diagnosed in 28 renal transplant recipients followed up in our institute between January 2003 and November 2010.

Among 28 cases of AVR, 18 were mild (v1 in Banff 07 classification), 8 were moderate (v2), and 2 were severe (v3). Interstitial inflammation was present in 25 biopsy specimens. Moderate to severe tubulitis (t2-t3) was present in 10 biopsy specimens and transplant glomerulitis in 17; peritubular capillaritis was in 25 of the 28 biopsy specimens. C4d deposition in peritubular capillaries was observed in 11/28 cases. By using assays with plastic beads coated with human leukocyte antigen (HLA) in the 28 cases, we detected circulating anti-HLA alloantibody in 18 patients, among which 11/28 were donor-specific. Acute antibody-mediated rejection was diagnosed in 6 cases. Among AVR cases, 19/28 displayed steroid-resistant rejection (SRR) requiring greater anti-rejection therapy (ART), including muromonab CD3 injection, gusperimus injections, plasmapheresis, intravenous immune globulin, and/or rituximab injections. Twenty of 28 patients recovered renal allograft function after ART, and 26/28 grafts are functioning. Among the 2 cases of graft loss, only 1 patient lost his graft due to AVR.

In some cases, AVR might be provoked by anti-donor antibodies. The prognosis of the graft exhibiting AVR was relatively good using available immunosuppression.