ABSTRACT
PURPOSE: C4d detection in peritubular capillaries in acute allograft rejection has been regarded as a poor prognostic factor for graft kidney survival. We investigated the clinical importance of C4d positivity in renal transplant recipients with acute rejection. METHODS: Forty eight renal allograft biopsies were selected, which were available for immunofluorescence study. The samples were divided into two groups, one which was diagnosed as acute rejection clinically (n=30), the other which underwent protocol biopsy 2 weeks after transplantation (n=18). Among the acute rejection group, C4d staining was positive in 50% of acute rejection cases (C4d (+), n=15) and negative in the others. (C4d (-), n=15). We compared the C4d (+) group and the C4d (-) group in terms of clinical parameters and graft survival duration. RESULTS: Renal function was reduced in the C4d (+) group compared to the C4d (-) group. In the C4d (+) group, 8 of 15 cases resulted in graft loss, but only one graft loss developed in the C4d (-) group. Graft survival duration after kidney biopsy was reduced in the C4d (+) group compared to the C4d (-) group. CONCLUSION: Renal transplant recipient with C4d-positive acute rejection shows inferior graft survival duration. So tight management in addition to steroid pulse therapy should be considered for these patients.