P0408kidney Transplantation Outcomes in Patients With Iga Nephropathy in the Modern Era of Immunosuppression: A Case Control Study

Abstract

Background and Aims Advances in immunosuppressants, used for kidney transplantation (KTx) have significantly improved outcomes in this field. We aimed to compare the long-term results of KTx in recipients with IgAN, as cause of end stage kidney disease (ESKD), with those of patients, with non-glomerular causes of renal failure, during the modern era of immunosuppression for KTx. Method This is a retrospective, case control study, in which were included patients who received a KTx after 2000. Patients were eligible to be included, if they had IgAN in a native kidney biopsy specimen and follow up longer than 1 year after KTx. IgAN patients were compared to a control-group of patients with non-glomerular primary causes of ESKD matched for age, gender, date of KTx and donor source. Graft biopsies were performed by clinical indication. Patients with ABO incompatible KTx, preemptive KTx, re-KTx, PRA>50%, major surgical complications during the 1st post-KTx month or non-compliance were excluded from the analysis of outcome. Primary outcomes of interest included graft function, patient and graft survival at end of follow up. The rate of IgAN recurrence in the graft and its impact in renal function and survival were also recorded. Computed GFR was calculated using the Modification of Diet in Renal Disease formula. Results A total of 102 KTx recipients with biopsy-proven IgAN, were compared to 204 controls with non-glomerular causes of ESKD. The mean age of patients with IgAN was 43.2(±10.15) years and 68(66.7%) were men. The mean time in dialysis was 50.2(±48.7) months and 59(57.8%) of them received a graft from a living donor. The mean cold ischemia time was 17.5(±6.7) hours, while 22(21.6%) of patients experienced delayed graft function. 97.05% of patients received induction therapy with an anti-CD25 inhibitor and 99.3% were maintained with a triple immunosuppressive regimen consisted of a mycophenolate mofetil formulation, a calcineurin inhibitor and glucocorticoids. The mean serum creatinine and eGFR at end of follow up were significantly lower for the IgAN group (p=0.001 and p=0.02 respectfully) with no difference in the frequency of acute rejection. However, graft and patient survival were not different even after controlling for follow up longer than one decade. During a mean follow up time of 120.8(±49.1) months, IgAN recurrence in the graft was documented in 23(22.5%) patients. The mean time to recurrence was 47.8(41.8) months, with a mean serum creatinine 1.83(±0.52) mg/dl and eGFR of 43.45(±18.4) ml/min/1.73m2 at the end of follow up. Within the IgAN group, although graft function was significantly lower in patients with disease recurrence, compared with that of patients without recurrence (p=0.003), graft loss remained not different between these two subgroups (p=0.49). Conclusion In the newer era of immunosuppression, long-term outcomes of KTx in patients with IgAN, as primary disease, appear significantly improved, and although graft function was significantly lower in patients with IgAN at the end of follow up, graft and patient survival was not different, compared to patients with non-glomerular causes of ESKD. Recurrence of IgAN in the graft was documented in 22.5% of patients and was associated with significantly lower eGFR at end of follow up compared to patients without recurrence but it did not impact graft survival in this time period.