Objective  To evaluate the relationship between serum IgG4 levels and CT morphological changes of abdominal organs involved in autoimmune pancreatitis (AIP).

  Methods  Serum IgG4 levels, pancreas and other involved abdominal extrapancreatic organs' CT morphological changes of 19 clinically diagnosed AIP patients who had complete related information were retrospectively analyzed. The patients were divided into two groups (recovering and non-recovering) according to the above three aspects. Consistency among serum IgG4 levels, morphological changes of the pancreas and morphological changes of involved abdominal extrapancreatic organs was evaluated by Fisher exact test.

  Results  In total, 13/19 patients had consistent trend between serum IgG4 level and pancreatic morphological changes (P=0.169); 15/19 had consistent trend between serum IgG4 level and morphological changes of involved abdominal extrapancreatic organs (P=0.013); 15/19 patients had consistent trend in morphological changes between the pancreas and involved abdominal extrapancreatic organs (P=0.020).

  Conclusions  The trend of serum IgG4 level and morphological changes of involved abdominal extrapancreatic organs have a good consistency, so do the morphological changes of the pancreas and involved abdominal extrapancreatic organs, while the trend of serum IgG4 level appears to have a poor consistency with the morphological changes of the pancreas.