Assessment of islet function following islet and pancreas transplantation

Abstract

Pancreas and islet transplant recipients are monitored using various metabolic and imaging methods. The inaccessibility of the transplanted whole pancreas and of the isolated islets poses specific problems (eg, all assessment techniques are indirect). Although successful pancreas transplantation typically restores normal glucose homeostasis, islet transplantation into the liver does not completely normalize islet hormone secretion and glucose metabolism. Development of better testing strategies, such as direct islet imaging, will significantly advance the field.

Figure 1

Local glycogen deposition surrounding an intrahepatic islet allograft in a nonhuman primate. PAS—periodic acid–Schiff.

Figure 2

Two National Institutes of Health patients, who received islet allografts 5 years prior, have persistent C-peptide secretion up to the present time. Depicted are their C-peptide responses (defined as the maximum C-peptide concentration [mean of the highest three values after arginine stimulation] minus the mean of two baseline values). After introduction of exogenous long-acting insulin, decreased C-peptide responses were observed and restored after omission of insulin 24 hours prior to testing.