Focal C4d + in Renal Allografts is Associated with the Presence of Donor Specific Antibodies and Decreased Allograft Survival

摘要

Diffuse peritubular capillary C4d deposition in renal allograft biopsies is associated with donor specific antibodies (DSA) and graft failure. The significance of focal C4d+ is unclear. We reviewed 368 biopsies from 301 patients performed for renal dysfunction or proteinuria over 5-years. Diffuse C4d+, focal C4d+, and C4d- detected by immunofluorescence occurred in 9.5%, 20.9% and 69.4% of biopsies, respectively. Patients were similar in gender, age, cause of renal disease, donor source, HLA mismatch, serum creatinine at baseline and interval from transplantation to biopsy. Diffuse and focal C4d+ were associated with acute cellular rejection (p<0.001). Transplant glomerulopathy was associated with diffuse C4d+. DSA at the time of biopsy, were positive in 79.3% of diffusely C4d+ patients, 68.8 % of those with focal C4d+ (P=0.27) and 9.9% of patients with C4d- (P< 0.001, compared to either the focal or diffuse groups, respectively). Allograft survival at 40 months was lower in diffuse C4d+ compared to the C4d- group (P=0.014), but not when compared to the focal C4d+ group. There was a clear trend towards worse graft survival in patients with focal C4d+ in this time interval, but focal C4d+ compared to both diffuse C4d+ and C4d-groups was not statistically significant (p=0.08).