Islet Isolation Outcomes in Patients Undergoing Total Pancreatectomy with Islet Autotransplantation in the POST Consortium

Background. In total pancreatectomy with islet autotransplantation (TPIAT), a greater number of islets transplanted produces more favorable outcomes. We aimed to determine predictors of islet isolation outcomes. Methods. We investigated factors associated with islet isolation outcomes expressed as islet number (IN), islet equivalents (IEQ; standardized to an islet with 150 μm diameter), IN/kg, or IEQ/kg using data from the multicenter Prospective Observational Study of TPIAT. Single-predictor linear regression was used to estimate the association of individual patient and disease characteristics with islet isolation outcomes, and augmented backward elimination was used to select variables to include in multivariable analyses. Results. In multivariable analyses, only elevated hemoglobin A1c was associated with worse outcomes for all measures (P < 0.001 for all). Total IEQ obtained for transplant was higher for participants with Hispanic ethnicity (P = 0.002) or overweight status pre-TPIAT (P < 0.001) and lower with non-White race (P = 0.03), genetic pancreatitis (P = 0.02), history of lateral pancreaticojejunostomy (P = 0.03), and presence of atrophy (P = 0.006) or ductal changes (P = 0.014) on imaging. IEQ/kg was higher in females (P = 0.01) and Hispanic participants (P = 0.046) and generally lower with older age (nonlinear association, P < 0.001) and pancreatic atrophy (P < 0.001) on imaging. Total IN and IN/kg showed trends similar, but not identical, to IEQ and IEQ/kg, respectively. Conclusions. Patient demographics and certain pancreatic disease features were associated with outcomes from islet isolation. Hemoglobin A1c before TPIAT was the metabolic testing measure most strongly associated with islet isolation results.