C4d-positive Renal Transplants: Single-center Clinical Outcomes.

Ciszek M, Ptasińska AP, Durlik M, Paczek L.

Clinical Transplants 2006, Chapter 33

Abstract

Among 269 biopsies performed in our institution in 2006, 24 biopsies were C4d positive. There were seven cases of early AMR (< 6 months post-transplant) and 17 cases of late AMR. Cellular rejection was found in 12 biopsies (50%) and classified as type I tubulointerstitial (six biopsies: five Banff IA and one Banff IB) and type II vascular (six biopsies: Banff IIA); in five biopsies (21%), borderline rejection was diagnosed. Changes consistent with chronic rejection were found in six biopsies (25% of all and 35% of biopsies in the late post-transplant period). Among patients with early-onset AMR, there were three cases with thrombotic microangiopathy. Graft function improved in all cases of early AMR after treatment with steroid pulses, and in two cases it improved with ATG and increasing doses of MMF, respectively. All of these patients showed good graft function during follow-up. Methylprednisolone pulses with various modifications of immunosuppressive protocols were used for treatment of late-onset AMR with rather poor effect. Graft function improved in only five patients (29%) but decreased thereafter in three cases; dialysis was started in four cases (24%), and one patient died in sepsis. AMR could be associated with various histological features; trombotic microangiopathy was the specific type of injury for the early-onset AMR in our study, and all but one late-onset AMR were associated with chronic changes. Conventional treatment of acute rejection with steroid pulses or ATG was effective in cases of AMR diagnosed early after transplantation but was of little benefit in cases during the late post-transplant period. Treatment with plasmapheresis with or without immunologlobins or rituximab could be the best therapy in such cases.