Study protocol: a pilot study to determine the safety and efficacy of induction-therapy, de novo MPA and delayed mTOR-inhibition in liver transplant recipients with impaired renal function. PATRON-study.

BACKGROUND: Patients undergoing liver transplantation with preexisting renal dysfunction are prone to further renal impairment with the early postoperative use of Calcineurin-inhibitors. However, there is only little scientific evidence for the safety and efficacy of de novo CNI free "bottom-up" regimens in patients with impaired renal function undergoing liver transplantation. This is a single-center study pilot-study (PATRON07) investigating safety and efficacy of CNI-free, "bottom-up" immunosuppressive (IS) strategy in patients undergoing liver transplantation (LT) with renal impairment prior to LT. METHODS/DESIGN: Patients older than 18 years with renal impairment at the time of liver transplantation eGFR < 50 ml/min and/or serum creatinine levels > 1.5 mg/dL will be included. Patients in will receive a CNI-free combination therapy (basiliximab, MMF, steroids and delayed Sirolimus). Primary endpoint is the incidence of steroid resistant acute rejection within the first 30 days after LT. The study is designed as prospective two-step trial requiring a maximum of 29 patients. In the first step, 9 patients will be included. If 8 or more patients show no signs of biopsy proven steroid resistant rejection, additional 20 patients will be included. If in the second step a total of 27 or more patients reach the primary endpoint the regimen is regarded to be safe and efficient. DISCUSSION: If a CNI-free-"bottom-up" IS strategy is safe and effective, this may be an innovative concept in contrast to classic top-down strategies that could improve the patient short and long-time renal function as well as overall complications and survival after LT. The results of PATRON07 may be the basis for a large multicenter RCT investigating the new "bottom-up" immunosuppressive strategy in patients with poor renal function prior to LT.http://www.clinicaltrials.gov-identifier: NCT00604357.

Improved outcome after 'bottom-up' immunosuppression in liver transplant recipients with preoperative renal impairment.

BACKGROUND: Most patients with high MELD scores have impaired renal function prior to transplantation. PATIENT AND METHODS: A retrospective case control study was conducted with initial low immunosuppression, which was increased when patients rejected or were clinically stable beyond day 30 ('bottom-up'). RESULTS: Thirty patients with impaired renal function were included. Fifteen were treated with de novo cyclosporine A (CsA; group A), and 15 had 'bottom-up' immunosuppression (group B). Baseline renal function was similar: serum creatinine (SCr) median 1.8 mg/dl (range: 1.5-4.0 mg/dl; group A) versus 2.4 mg/dl (range: 1.5-4.0 mg/dl; group B; p = 0.24). The requirement for renal replacement therapy was significantly lower in group B (p = 0.032). Ten received 'bottom-up' immunosuppression [4 CsA/1 sirolimus (Sir) 'on demand' after rejection, 5 Sir (stable)] beyond day 30. By months 6 and 12 (1.6 mg/dl vs. 1.2 mg/dl), SCr values were significantly better in group B (p = 0.006). Renal function in group B did not differ between patients receiving CsA or Sir. Overall complication rates, survival and biopsy-proven acute rejection were similar, although BANFF scores were higher in group B (p = 0.004). CONCLUSION: Successful implementation of 'bottom-up' immunosuppression in liver transplant recipients with high lab-MELD scores and renal dysfunction at the time of transplantation has the potential to substantially improve short- and long-term outcomes.

Calcineurin Inhibitor Free De Novo Immunosuppression in Liver Transplant Recipients With Pretransplant Renal Impairment: Results of a Pilot Study (PATRON07).

BACKGROUND: Renal impairment and high model of end-stage liver disease scores before liver transplantation (LT) are increasingly common. PATIENTS AND METHODS: This was a single-arm, 2-step prospective trial of bottom-up calcineurin inhibitor (CNI)-free de novo immunosuppressive treatment (mycofenolate mofetil, steroids, basiliximab) with delayed introduction of sirolimus in patients with renal impairment. Primary endpoint was immunologic safety assessed by the incidence of steroid-resistant rejection within the first 30 days after liver transplantation. RESULTS: Twenty-seven patients were included with a median age of 56 years and labMELD of 28. Baseline glomerular filtration rate was 38 (Cockroft-Gault) and 24 mL/min (modification of diet in renal disease). No steroid-resistant rejections occurred within 30 days. Incidence of biopsy proven acute rejection was 18.5%. Sirolimus was started on day 10 (range, day 1 to day 48). The rate switched to CNI treatment by 1 year was 44%; 1-year overall survival was 93%. Renal function improved significantly, reflected by a Δglomerular filtration rate of 31 mL/min from baseline to 1 year (P = 0.006). Per protocol analysis revealed freedom from CNI, but not presence of sirolimus within the first 30 days, as critical for renal recovery. CONCLUSIONS: Initial de novo CNI-free immunosuppressive bottom-up treatment is safe in selected patient groups. The critical period for relevant recovery of renal function seems to be the early period (first 30 days), independent from presence of sirolimus.