C4d-positive acute humoral renal allograft rejection: Rescue therapy by immunoadsorption in combination with tacrolimus and mycophenolate mofetil

Abstract

Objective We investigated the efficacy of immunoadsorption (IA) in combination with tacrolimus (FK506) and mycophenolate mofetil (MMF) rescue therapy for C4d-positive acute humoral rejection (AHR) of renal transplants. Methods Six of 185 cadaveric renal allograft recipients developed AHR at a mean of 4.8 ± 0.8 days after the operation. C4d deposits were observed in peritubular capillaries (PTC) with accumulation of granulocytes. IA with staphylococcal protein A and FK506-MMF combination therapy were administered. Results After treatment with IA for 6.3 ± 1.03 sessions combined with FK506 (0.14 to 0.16 mg · kg −1 · d −1) and MMF (1.5 g/d) therapy, renal function recovered in all the patients. The mean duration of treatment to a serum creatinine decrease was 14 ± 2.9 days. The pre-IA panel reactive antibody reactivity (PRA) peaked at 50.2% ± 6.1%, and was significantly reduced to 8.3% ± 2.9% after IA. In four of six patients repeat allograft biopsy revealed a remission of AHR. With a mean follow-up of 18.8 ± 5.46 months, patient and allograft survival are 100% and renal function remains stable with a mean serum creatinine of 1.2 ± 0.22 mg/dL. Conclusion The optimal treatment for alloantibody-mediated AHR remains uncertain. Our findings suggest that a therapeutic approach combining IA and FK506-MMF rescue improves the outcome of AHR.