Acute rejection features in dual kidney transplant recipients fromelderly donors: comparison of calcineurin inhibitor-based and calcineurininhibitor-free immunosuppressive protocols.

Features of acute rejection in dual kidney transplant have not been studied. The aim of this study is to compare acute rejections in dual kidney transplant recipients from elderly donors on different immunosuppressive protocols. Sixty-nine patients were evaluated: 28 received calcineurin inhibitor-based (group 1) and 41 received calcineurin inhibitor-free immunosuppression (group 2). Histology of all donor kidneys was evaluated before implantation. All rejections showed tubulitis in both groups, and were classified as T-cell mediated acute rejections. Incidence and Banff grade of rejections in the two groups were not significantly different. Late rejections however, were observed in group 1 (P < 0.01) whereas steroid-resistant rejections occurred in group 2 (P < 0.03). C4d deposition was only observed in group 2. Occurrence of acute rejection was significantly associated with graft loss due to interstitial fibrosis/tubular atrophy in both groups. In group 1 mean serum creatinine levels of patients with rejections at six months and one year were higher than those of patients without rejections (P < 0.03 and P < 0.009, respectively). In group 2 they were higher at six months (P < 0.01) but not at one year. In addition, graft loss due to interstitial fibrosis/tubular atrophy occurred in 3/28 patients in group 1 (10.7%, OR= 1.95, 95%CI 1.02-3.71), and in 1/41 patients in group 2 (2.4%, OR= 0.41, 95%CI 0.07-2.24). Taken together these results suggest better renal function in patients on calcineurin inhibitor-free immunosuppression. In conclusion, acute rejections were detrimental irrespective of the type of immunosuppression, but different features were observed with each therapy. A tailored approach should be advantageous for prevention and treatment of acute rejections.