Steroid Withdrawal in Pediatric Renal Transplant: Impact on Growth, Bone Metabolism and Acute Rejection

Steroid Withdrawal in Pediatric Renal Transplant: Impact on Growth, Bone Metabolism and Acute Rejection

Multicenter, Open-Label, Randomized Study on Steroid-Free Immunosuppression, in Comparison With Daily Steroid Therapy, in Pediatric Renal Transplant : Impact on Growth, Bone Metabolism and Acute Rejection

The present study investigates the safety and efficacy of steroid withdrawal at six days post-transplant in pediatric renal recipients under concomitant immunosuppression based on antibodies anti IL2 (interleukin 2), Tacrolimus (TAC) and Mycophenolate Mofetil (MMF). To investigate the impact of this protocol in growth, bone metabolism, insulin- sensitivity and evaluate the expression of IL17 (interleukin 17) and mRNA FOXP3 (messenger ribonucleic acid forkhead box protein 3) as early markers of acute rejection (blood, urine and renal biopsy). Hypothesis:Steroid withdrawal in renal pediatric transplant patients improves growth and bone metabolism without increasing the risk of acute rejection. The expression of FoxP3/IL17 in urine cells could be an early molecular markers of acute rejection.

The intention of this investigation is to evaluate a prospective immunosuppressive protocol based on antibodies anti IL-2 (Ac-IL-2), Tacrolimus (TAC) and Mycophenolate Mofetil (MMF)and withdrawal steroids in renal transplant and to compare with a steroid-based protocol. Objectives: To evaluate growth and the impairment in the GH/IGF (growth hormone/insulin like growth factor) axis To determine the impact of steroids on bone metabolism (biochemical parameters, DXA and pQCT) To determine the steroid effect on metabolic factors (dyslipidemia, insulin- sensitivity and arterial hypertension) To determine acute rejection incidence (protocol renal biopsy) To evaluate the expression of IL-17 and mRNA FoxP3 as early markers of acute rejection (blood, urine and renal biopsy). Two treatment regimes (Arms)will be compared in randomized form in the course of 12 months after transplantation. Arm A: TAC + MMF + withdrawal of steroids over a six-days following randomization. Arm B: TAC + MMF + prednisolone (see schedule)/day

Arms A: TAC + MMF + withdrawal steroids over a six-days following randomization. 1°day: Methylprednisolone iv, 2-3 mg/kg/d 3 doses 2ºday: Methylprednisolone iv, 2-3 mg/kg/d 3 doses 3°day: Prednisone 2 mg/kg/d in 2 doses 4ºday: Prednisone 1 mg/kg/d in 2 doses 5ºday: Prednisone 0.5 mg/kg/d in 2 doses 6ºday: Prednisone 0.25 mg/kg/d in 2 doses 7ºday: Stop Prednisone

Arms B: TAC + MMF + prednisolone (see schedule)/day 10°days after Tx: 2 mg/kg/d Day 11 - 20: 1 mg/kg/d Day 21 - 30: 0.5 mg/kg/d Day 31 - 60: 0.3 mg/k/d Week 8 - 12: 0.25 mg/k/d Week 12 - 16: 0.20 mg/k/d Week 16 - 20: 0.15 mg/k/d Month 6 - 12: 0.10 - 0.12 mg/k/d

Arms A: Tacrolimus (TAC)+ Mycophenolate Mofetil (MMF) + withdrawal steroids over a six-days following randomization. 1°day: Methylprednisolone iv, 2-3 mg/kg/d 3 doses 2ºday: Methylprednisolone iv, 2-3 mg/kg/d 3 doses 3°day: Prednisone 2 mg/kg/d in 2 doses 4ºday: Prednisone 1 mg/kg/d in 2 doses 5ºday: Prednisone 0.5 mg/kg/d in 2 doses 6ºday: Prednisone 0.25 mg/kg/d in 2 doses 7ºday: Stop Prednisone

Arms B: Tacrolimus (TAC)+ Mycophenolate Mofetil (MMF) + prednisolone (see schedule)/day 10°days after Tx: 2 mg/kg/d Day 11 - 20: 1 mg/kg/d Day 21 - 30: 0.5 mg/kg/d Day 31 - 60: 0.3 mg/k/d Week 8 - 12: 0.25 mg/k/d Week 12 - 16: 0.20 mg/k/d Week 16 - 20: 0.15 mg/k/d Month 6 - 12: 0.10 - 0.12 mg/k/d

Growth-factors (IGF-I, IGFBP-3) Bone Metabolism (FA, Ca/Cru, CaxP, 25(OH)VitD, FGF23, Klotho, PTH, DXA, pQCT) Insulin-sensitivity by ISI Method. Molecular Markers - Acute Rejection (FOXP3/IL-17). Acute Rejection Incidence/Protocol Renal Biopsy

Inclusion Criteria: Age < 16.0 years Bone age of boys < 15 years, of girls < 13 years Prepuberal Tanner Status I First or second kidney transplant, living or deceased kidney donation Immunosuppression with Tacrolimus (TAC),Mycophenolate mofetil (MMF) Patients and parents, respectively, have given their written consent after enlightenment (informed consent) Exclusion Criteria: Irreversible rejection of former transplant Highly reactive (> 30%) lymphocytotoxic antibodies within 12 months prior to transplantation Suspected insufficient medication compliance in dialysis Patients receiving a basic immunosuppression other than that prescribed in this protocol Simultaneous therapy with growth hormone after renal transplant