Cell-mediated and humoral acute vascular rejection and graft loss: A registry study.

Aims: Rejection of renal allografts following transplantation continues to be a major impediment to long-term graft survival. Although acute vascular rejection (AVR) is associated with a high risk of graft loss, it remains unclear whether AVR with accompanied cellular or acute humoral rejection (AHR) have dissimilar outcomes. The aim of this registry study was to examine the association between subtypes of AVR and graft loss.

Methods: Using Australia and New Zealand Dialysis and Transplant registry, primary kidney transplant recipients between 2005 and 2012 whose first rejection episode was AVR were included and categorized into AVR-none (AVR without other rejections), AVR-CG (AVR with cellular and/or glomerular rejections), and AVR-AHR (AVR with AHR). Association between AVR groups and graft loss was examined using logistic and Cox regression models.

Results: Of the 274 recipients, 61 (22.3%) experienced AVR-none, 79 (28.8%) AVR-AHR and 134 (48.9%) AVR-CG. Compared with AVR-none and AVR-CG, AVR-AHR was associated with the highest incidence of overall graft loss at 3 months (12%, 10% and 27%, respectively, χ(2) = 11.88, P = 0.003). AVR-AHR was associated with almost a threefold greater risk of death-censored graft loss compared with AVR-none (adjusted hazard ratio 2.84, 95% confidence interval 1.22-2.62, P < 0.01).

Conclusion: AVR-AHR is associated with the poorest outcome with over 25% of grafts being lost 3 months after transplantation. Future studies evaluating factors that predict graft loss in AVR-AHR may help determine prognosis and inform treatment practices.