Background: Relapse and spontaneous remission (SR) are characteristic features of autoimmune pancreatitis (AIP).
Aim and methods: We conducted a study to determine if the predictive factors might be potentially related to the relapse in 70 consecutive AIP patients. Regarding SR, we studied the data of patients without corticosteroid treatment (CST).
Results: CST was administered to 60% (42/70) of the patients; however, relapse was noted in 45.2% (19/42) of these patients. In 95% (18/19) of the AIP patients developing relapse, the relapse occurred within 3 years. The relapse rate was 80% (12/15) in the AIP patients administered CST for less than 12 months and 25.9% (7/27) in those administered CST for over 12 months (p < 0.01). The results of univariate analysis revealed significant association of relapse with the presence of jaundice, IgG4 seropositivity, presence of diffuse pancreas swelling, duodenal papillitis (DP), history of initial CST, and history of supportive treatment (p < 0.05), whereas multivariate analysis revealed that IgG4 seropositivity (OR 10.506, p = 0.0422) and the presence of jaundice (OR 6.945, p = 0.0174) are significant independent factors predictive of relapse in AIP patients. SR was recognized in 65.0% (13/20) of AIP patients without CST. The results of univariate analysis revealed that SR was associated with IgG4 seropositivity (p < 0.05), and multivariate analysis identified IgG4 seropositivity (OR 0.032, p = 0.0092) as a significant independent factor predictive of SR in these cases.
Conclusion: AIP patients with IgG4 seropositivity and jaundice are at a higher risk of relapse and they could therefore be candidates for over 3 years of maintenance CST. AIP patients with IgG4 seronegativity have a high likelihood of SR.