Correlation of Histopathology, Islet Yield, and Islet Graft Function After Islet Autotransplantation in Chronic Pancreatitis

Objective: The number of islets available (yield) is an important predictor of insulin independence after islet autotransplantation (IAT) done at the time of total pancreatectomy to treat painful chronic pancreatitis. The aim of this study was to correlate histopathologic findings with islet yield and graft function. Methods: Pancreatic histopathology was examined in 105 adults who underwent pancreatectomy and IAT; postoperative insulin use was known in 53 cases. Histologic degree of fibrosis, acinar atrophy, inflammation, and nesidioblastosis were scored by a surgical pathologist. The correlation of histopathology with islet yield and graft function was evaluated. Results: Patients received a median of 2968 islet equivalents per kilogram. Fibrosis and acinar atrophy correlated negatively with islet yield (P < 0.001, r = -0.67), as did inflammation (P < 0.001, r = -0.43). There was a positive correlation of islet yield (P < 0.0001, r = 0.64) and a negative correlation of fibrosis (P = 0.006, r = -0.43) and acinar atrophy (P - 0.006, r = -0.42) with islet graft function. Conclusion: More severe histopathologic changes were associated with a lower islet yield and lower likelihood of insulin independence. Total pancreatectomy and IAT should not be delayed in patients with painful chronic pancreatitis refractory to medical therapy; otherwise progressive damage to the pancreas may limit islet yield and increase the risk of diabetes.