Comparison of clinical characteristics of radiological forms of autoimmune pancreatitis.

Background: There is limited understanding of the clinical characteristics of different radiological forms of autoimmune pancreatitis (AIP). This retrospective study compared the clinical features of radiological forms of AIP.

Methods: A retrospective review was conducted of patients with AIP treated from 2005 to 2015. Based on radiological features, these AIP cases were classified as diffuse (D) or focal (F), and the latter further stratified as head (H), or body and/or tail (B/T). The clinical characteristics and laboratory indices were compared.

Results: Among the 119 patients, 66 (55.5%), 40 (33.6%), and 13 (10.9%) were respectively classified as D-, H-, and B/T-type. Compared with the others, the B/T-type patients were younger at onset, the percentage of men was lower, loss of appetite and weight were less common, and these patients had fewer extrapancreatic lesions (P < 0.05, each). Compared with the other groups, the B/T-type patients showed significantly lower levels of liver enzymes, direct bilirubin, and total bilirubin. No B/T-type patient displayed jaundice or pruritus. Three B/T-type patients progressed to D-type during the natural course of illness.

Conclusions: D-type and H-type AIP patients had similar clinical features. The B/T-type group differed significantly from the other two types. B/T-type can progress to D-type.