Key factors for human islet isolation and clinical transplantation

Background. To further improve the outcome of clinical islet transplantation analysis of the impact of donor- and process-related factors could be of great importance. Materials and Methods. Thirty-eight consecutive clinical islet transplantations were performed with consecutive islet isolations. Univariate analysis for donor- and isolation-related variables were correlated with recipient C-peptide levels at 2 and 4 weeks after transplantation. "Warm ischemia time" was defined as the time from start of University of Wisconsin solution perfusion in the donor until the pancreas was removed to the back table. Results. Short "warm ischemia time" (WIT), low expression of tissue factor (TF) in pancreatic tissue, and high creatinine levels in the donor were variables related to high C-peptide values after islet transplantation. Furthermore, hospitalization length longer than 4 days was associated with low C-peptide levels. The number of islet equivalents (IEQ) did not correlate with the clinical outcome, possibly due to the fact that IEQ number was included in the release criteria for clinical islet transplantation Conclusions. Successful clinical islet transplantation is strongly correlated with donor and pancreas procurement factors rather than isolation process-related variables. "WIT" may induce TF expression in the pancreatic tissues. TF has been identified as the main trigger of the instant blood-mediated-inflammatory reaction in clinical islet transplantation. Therefore, assay of TF expression in pancreatic tissues could be applied as useful screening tool to identify "good" pancreata for clinical transplantation.