Timing of pre-emptive living donor transplantation

Transplantmedium

A 50-year-old woman presents for follow-up in the kidney transplant evaluation clinic. She has a history of CKD stage 4 secondary to IgA nephropathy. Kidney function has slowly worsened over the last 5 years. Her current medications include lisinopril and amlodipine. BP is 125/75 mm Hg. Physical examination is unremarkable. Laboratory studies show a serum creatinine of 2.2 mg/dL (reference range, 0.5–1.1) with eGFR 25 mL/min/1.73 m² (reference range, ≥60). She previously completed her evaluation and has no contraindications to kidney transplantation. Her husband was found to be a suitable donor. The patient asks when kidney transplantation should be performed. Which ONE of the following is the OPTIMAL time for this patient to undergo kidney transplantation?

  1. A.After 90 days of dialysis
  2. B.Once eGFR is <20 mL/min/1.73 m2Correct
  3. C.Once uremic symptoms develop
  4. D.As soon as possible

Explanation

Patients for whom pre-emptive kidney transplant is available should undergo transplantation once the eGFR falls below 20 mL/min/1.73 m². Pre-emptive transplantation is associated with improved patient and allograft outcomes, so should not be delayed until after dialysis is initiated or uremic symptoms develop. The renal replacement therapy options available for the treatment of ESRD are dialysis and kidney transplantation. Overall, kidney transplantation in patients with ESRD is associated with improved patient survival compared with dialysis. Several studies have shown that pre-emptive transplantation (before initiation of dialysis) is associated with improved patient and allograft survival compared with transplantation after dialysis. Furthermore, in patients who receive a kidney transplant after dialysis, longer time on dialysis is associated with worse post-transplant outcomes. Therefore, pre-emptive kidney transplantation is the preferred treatment for eligible patients with advanced CKD. The United Network for Organ Sharing (UNOS) rules state that eGFR should be <20 mL/min/1.73 m² for pre-emptive transplantation. This threshold is based on operative risks of kidney transplantation and data showing no additional benefit to pre-emptive transplantation in patients with eGFR >20 mL/min/1.73 m² compared with <20 mL/min/1.73 m². The patient described in the scenario has an eGFR of 25 mL/min/1.73 m², so she should not proceed with transplantation at this time. Transplantation should be delayed until eGFR is consistently <20 mL/min/1.73 m². The rate of progression is also important to consider because some patients with chronic tubulointerstitial disease may have very slow kidney function decline. Most patients with advanced CKD will undergo pre-emptive transplantation when eGFR is <15 mL/min/1.73 m². It is not necessary to delay pre-emptive transplantation until the emergence of uremic symptoms. To do so would risk the need to initiate dialysis to stabilize a patient prior to transplantation and might negate the advantage of pre-emptive transplantation.

Why each option

A.
Any time on dialysis before transplantation worsens patient and graft outcomes, so waiting for 90 days of dialysis forfeits the pre-emptive advantage.
B.
Correct. Pre-emptive living donor transplantation once eGFR is consistently below 20 mL/min/1.73 m² maximizes patient and graft survival without premature surgery.
C.
Waiting for uremic symptoms risks urgent dialysis initiation before surgery and may negate the survival advantage of pre-emptive transplantation.
D.
Transplanting at eGFR 25 exposes her to operative risk earlier than needed, with no added benefit over pre-emptive transplantation below 20.

Reference: KDIGO 2020 Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

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