C-peptide levels do not correlate with pancreas allograft failure: Multicenter retrospective analysis and discussion of the new OPT definition of pancreas allograft failure.

The OPTN Pancreas Transplantation Committee performed a multicenter retrospective study to determine if undetectable serum C-peptide levels correspond to center-reported pancreas graft failures. C-peptide data from seven participating centers (n = 415 graft failures for transplants performed from 2002 to 2012) were analyzed pretransplant, at graft failure, and at return to insulin. One hundred forty-nine C-peptide values were submitted at pretransplant, 94 at return to insulin, and 233 at graft failure. There were 77 transplants with two available values (at pretransplant and at graft failure). For recipients in the study with pretransplant C-peptide <0.75 ng/mL who had a posttransplant C-peptide value available (n = 61), graft failure was declared at varying levels of C-peptide. High C-peptide values at graft failure were not explained by nonfasting testing or by individual center bias. Transplant centers declare pancreas graft failure at varying levels of C-peptide and do not consistently report C-peptide data. Until February 28, 2018, OPTN did not require reporting of posttransplant C-peptide levels and it appears that C-peptide levels are not consistently used for evaluating graft function. C-peptide levels should not be used as the sole criterion for the definition of pancreas graft failure.

Migration of Patients for Liver Transplantation and Waitlist Outcomes.

BACKGROUND & AIMS: Patients in need of liver transplantation may travel to improve their chance of receiving an organ. We evaluated factors to determine which transplant candidates travel to other regions to increase their chances of receiving a liver and effects of travel on waitlist outcomes. METHODS: We performed a retrospective cohort study of all adult patients registered for primary deceased donor liver transplantation in the United States from January 2004 to December 2016. Zip code data were used to calculate the travel distance from a patient's residence to centers at which they were on the waitlist or received a liver transplant. Distant listing and migration were defined as placement on a waitlist and receipt of liver transplantation, respectively, outside the home transplantation region and greater than 500 miles from the home zip code. We assessed the effect of distant listing on outcomes (death and liver transplantation) and predictors of distant listing or migration using multivariable analyses. RESULTS: There were 104,914 waitlist registrations during the study period; of these, 2930 (2.8%) pursued listing at a distant center. Of waitlist registrants, 60,985 received liver transplants, of whom 1985 (3.3%) had migrated. In a multivariable competing risk analysis in which liver transplantation was considered as a competing event, distant listing was associated with a 22% reduction in the risk of death within 1 year (subhazard ratio, 0.78; 95% CI, 0.70-0.88). Distant listing and migration were associated with non-black race, non-Medicaid payer, residence in a higher income area, and education beyond high school. CONCLUSIONS: Placement on a liver transplant waitlist outside the home transplantation region is associated with reduced waitlist mortality and an increased probability of receiving a liver transplant. Geographic disparities in access to liver transplantation have disproportionate effects on patients who are minorities, have lower levels of education, or have public insurance.