Predictive Factors for Relapse in Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a distinct inflammatory pancreatic disorder characterized by its responsiveness to glucocorticoid therapy and association with autoimmune features. AIP primarily consists of type 1 and type 2, with relapse being a significant problem mainly associated with type 1 AIP, which has a high relapse rate of approximately 40%, whereas type 2 AIP has significantly lower relapse rates. This narrative review comprehensively examines the multifaceted factors influencing AIP relapse, particularly focusing on type 1 AIP. Dynamic changes in serum IgG4 levels-particularly insufficient decline, relative increase, or persistently elevated levels after steroid therapy-consistently correlate with relapse risk. Other serological markers including IgE and autotaxin may serve as potential relapse predictors. Imaging features associated with relapse include diffuse pancreatic swelling, persistent post-treatment pancreatic enlargement, and elevated FDG-PET metabolic parameters. Extra-pancreatic involvement, especially proximal biliary and renal manifestations, significantly increases relapse risk. Therapeutic considerations reveal that prolonged maintenance glucocorticoid therapy reduces relapse rates, while immunosuppressants and rituximab show promise in managing refractory cases. This review synthesizes current evidence to guide clinicians in developing effective management strategies for this challenging pancreatic disorder.