Preservation of kidney function in kidney transplant recipients by alkali therapy (Preserve-Transplant Study): rationale and study protocol

BMC Nephrol. 2018 Jul 13;19(1):177. doi: 10.1186/s12882-018-0956-8.


Background: Graft survival after kidney transplantation has significantly improved within the last decades but there is a substantial number of patients with declining transplant function and graft loss. Over the past years several studies have shown that metabolic acidosis plays an important role in the progression of Chronic Kidney Disease (CKD) and that alkalinizing therapies significantly delayed progression of CKD. Importantly, metabolic acidosis is highly prevalent in renal transplant patients and a recent retrospective study has shown that metabolic acidosis is associated with increased risk of graft loss and patient death in kidney transplant recipients. However, no prospective trial has been initiated yet to test the role of alkali treatment on renal allograft function.

Methods: The Preserve-Transplant Study is an investigator-initiated, prospective, patient-blinded, multi-center, randomized, controlled phase-IV trial with two parallel-groups comparing sodium bicarbonate to placebo. The primary objective is to test if alkali treatment will preserve kidney graft function and diminish the progression of CKD in renal transplant patients by assesing the change in eGFR over 2 years from baseline. Additionally we want to investigate the underlying pathomechanisms of nephrotoxicity of metabolic acidosis.

Discussion: This study has the potential to provide evidence that alkali treatment may slow or reduce the progression towards graft failure and significantly decrease the rate of end stage renal disease (ESRD), thus prolonging long-term graft survival. The implementation of alkali therapy into the drug regimen of kidney transplant recipients would have a favorable risk-benefit ratio since alkali supplements are routinely used in CKD patients and represent a well-tolerated, safe and cost-effective treatment.

Trial registration: NCT03102996 . Trial registration was completed on April 6, 2017.

Keywords: Graft function; Graft outcome; Metabolic acidosis; Sodium bicarbonate; eGFR.

Publication types

  • Clinical Trial, Phase IV
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkalies / pharmacology
  • Alkalies / therapeutic use*
  • Graft Survival / drug effects
  • Graft Survival / physiology
  • Humans
  • Kidney / physiology*
  • Kidney Transplantation / adverse effects
  • Kidney Transplantation / methods*
  • Prospective Studies
  • Retrospective Studies
  • Single-Blind Method
  • Sodium Bicarbonate / pharmacology
  • Sodium Bicarbonate / therapeutic use*
  • Transplant Recipients*
  • Treatment Outcome


  • Alkalies
  • Sodium Bicarbonate

Associated data