Elevated C-peptide Levels Are Associated With Acute Rejection in Kidney Pancreas Transplantation.

Background: We assessed whether allograft rejection or failure can be predicted by an acute increase in C-peptide production from the transplanted pancreas.

Methods: Patients with a minimum of 5 years of follow-up post simultaneous pancreas-kidney transplant were identified. C-peptide levels were obtained during clinic visits routinely. Graft failure was defined as return to dependence on insulin therapy or return to dialysis for pancreas and kidney grafts, respectively. Protocol kidney allograft biopsies were performed at 3 and 12 months. For-cause biopsies were also performed.

Results: Acute rejections were detected in 11 patients on biopsy results of the renal allograft. C-peptide levels drawn prior to documented rejections were significantly higher in patients with acute rejection than patients with borderline or no rejection (P = .006). Receiver operating characteristics curves for C-peptide indicated greater accuracy in predicting rejection than simultaneously drawn serum creatinine or lipase.

Conclusions: Higher C-peptide levels in simultaneous pancreas-kidney recipients is associated with acute rejection vs nonrejection.