Biopsy of the pancreas: the predictive value and therapeutic impact on autoimmune diabetes

Diabetes mellitus is by definition an end-stage organ failure. Type 1 diabetes mellitus is an autoimmune disease. Autoinflammatory infiltrate appears to characterize the insulitis associated with type 1 diabetes mellitus. In recent times, a comprehensive composition of peri-islet capsules and their basement membrane (BM) has been described. Lymphocytic infiltration around the islets without invasion of the BM is the first step in disease induction (nondestructive insulitis phase). Invasion of the BM by leukocytic infiltration (destructive insulitis phase) occurs over a period of several years, offering good window for therapeutic intervention. Clinical symptoms appear only when 70-90% of β-cell mass are destroyed. These data emphasize on the importance of identification and classification of such pathologic features by performing a biopsy of the pancreas, along with histoimmunochemistry analysis at the prehyperglycemic stage in a high-risk, genetically predisposed, autoimmune-suspected patient, which may at least in part help in achieving new therapeutic approaches and halting the progression to end-stage pancreatic disease known as diabetes mellitus. In this review, we emphasize the predictive role biopsy of the pancreas can have, by building up a solid gold standard tool in the diagnosis, staging, and therapeutic follow-up of autoimmune diabetes mellitus.