Pretransplant Serum Creatinine in Peritoneal Dialysis Patients Predicts Graft Outcomes

Although peritoneal dialysis (PD) as a pretransplant dialysis modality is associated with favorable outcomes after kidney transplant, it is unknown if pretransplant serum creatinine (Scr) level is associated with subsequent graft outcomes in candidates managed with PD. Our objective was to examine the association between Scr at the time of transplant and short-term and long-term outcomes posttransplant.

Retrospective cohort study.

A total of 20,166 adult (≥18 years of age) patients who were receiving PD at the time of a first living or deceased donor kidney transplant in the United States between 2000 and 2017, identified using the Scientific Registry of Transplant Recipients database.

Primary exposure was final Scr level before transplant, categorized as <5, 5-8, 8-12, and >12 mg/dL. Sensitivity analyses for patient subgroups included recipient age (≥50 vs <50 years) and dialysis vintage (≥3 vs <3 years) at transplant.

The primary outcome was death-censored graft loss (DCGL). Secondary outcomes included all-cause graft loss and delayed graft function (DGF).

Pretransplant Scr was significantly associated with DCGL (adjusted HR, 1.17; 95% CI, 1.02-1.34 for Scr >12 mg/dL [reference <5 mg/dL]) and DGF (adjusted OR, 2.71; 95% CI, 2.26-3.26 for Scr >12 mg/dL [reference <5 mg/dL]). There was no association with all-cause graft loss. The risk of DCGL and DGF associated with high pretransplant Scr was higher for those who were older (≥50 years) and those with longer dialysis vintage (≥3 years).

No access to potential predictors of pretransplant Scr including residual kidney function, dialysis adequacy and adherence; exact timing of Scr values pretransplant was unknown.

To our knowledge, this is the first study to explore the association between pretransplant Scr level in PD patients and graft outcomes after kidney transplantation. The reason for this increased risk is unclear but may reflect reduced residual kidney function, among other factors.