C-peptide and combined kidney-pancreas transplantation

Simultaneous transplantation of kidney and pancreas (SKP) is an excellent treatment option for patients with type I diabetes mellitus with end-stage renal failure. The risk associated with the procedure is somewhat higher than that with transplantation of a kidney alone. This excess risk relates to a higher likelihood of rejection, necessitating on average higher levels of immunosuppression, as well as an increased surgical risk regarding thrombosis of the pancreatic graft and infection. In suitable patients, however, this excess risk is offset by the fact that successful SKP ensures a life free of dialysis and insulin. Traditionally, SKP has been reserved for patients with type I diabetes mellitus while type II diabetes has been regarded as a contraindication. Most transplant centres also believe that C-peptide levels are helpful to distinguish between the two and require a Cpeptide assay as part of the workup for SKP. In this regard, we present a case that provided a surprise during workup for SKP. We briefly discuss the relevant literature and highlight current controversies regarding C-peptide levels and workup for SKP. The case presented here initially deceived us after numerous seasoned clinicians all claimed that he had type I diabetes. It was only after his markedly elevated C-peptide levels came back that we refuted a diagnosis of type I diabetes and abandoned the plan of SKP.