Patients returning to peritoneal dialysis (PD) from failed renal transplantation are recognized to be inflamed, and this situation might produce a high peritoneal solute transport status. We wanted to determine if a period of time with a kidney allograft induces a change in peritoneal function. We studied 19 PD patients who had been living with a graft for a mean of 47 +/- 39 months. We studied their peritoneal function upon starting PD (baseline), immediately before transplantation (pre-Tx), and after returning to PD when the graft failed (post-Tx). We analyzed the peritoneal mass transfer coefficients for urea (U-MTAC) and creatinine (Cr-MTAC), the dialysate-to-plasma ratio of creatinine (D/P-Cr), and net ultrafiltration (UF). We observed no significant differences in the various variables pre-Tx and post-Tx. The U-MTAC post-Tx was significantly lower than at PD baseline (25.9 +/- 8 mL/min vs. 20.2 +/- 5 mL/min, p = 0.03). The U-MTAC and Cr-MTAC post-Tx were not correlated with months on a graft or with MTAC values at baseline. In inherent high transporters (Cr-MTAC > or = 11.5 mL/min at baseline, n = 8), we observed a significant reduction in Cr-MTAC post-Tx (15.2 +/- 2 mL/min vs. 10.2 +/- 4 mL/min, p = 0.03). Three of these patients remained high transporters post-Tx. We conclude that peritoneal function upon reinitiating PD after transplantation is similar to function in the pre-transplantation phase; and that a high peritoneal transport status is more prevalent at first initiation onto PD than at return after transplantation, suggesting that inherently high transport is almost exclusively a feature of an intact, predialysis peritoneum.