Defining pancreatic damage and symptom burden in IgG4-related autoimmune pancreatitis: A cross-sectional study of 118 patients from a single-center registry

Objectives

Type 1 autoimmune pancreatitis is a common manifestation of IgG4-related disease (IgG4-RD). However, there is a paucity of literature characterizing pancreatic damage and symptom burden in IgG4-RD.

Methods

We performed a cross-sectional analysis of patients who fulfilled the ACR/EULAR IgG4-RD Classification Criteria. Disease features and complications were collected by medical record review. A survey regarding symptoms and disease history was distributed to all patients. Characteristics were compared between patients with and without autoimmune pancreatitis.

Results

Of 303 patients who fulfilled Classification Criteria at the time of the chart review, 118 (39 %) had evidence of autoimmune pancreatitis. Overt indicators of acute pancreatitis (e.g., abdominal pain, nausea/emesis, elevated serum lipase) each occurred in fewer than 50 % of patients with autoimmune pancreatitis. Diabetes mellitus (DM), exocrine pancreatic insufficiency (EPI), or both were present in 47 %, 48 %, and 21 % of the autoimmune pancreatitis patients, respectively. After encouraging all patients to have fecal elastase measured, 40/49 (82 %) stool samples had low elastase concentrations. 9/118 (8 %) had undergone pancreatic resections before the diagnosis was established. 162/325 (50 %) completed surveys (n = 81 [50 %] with autoimmune pancreatitis). Patients with autoimmune pancreatitis reported a higher burden of abdominal pain, weight loss, and changes in stool than those without (all p < 0.05).

Conclusion

Despite an often subclinical presentation, autoimmune pancreatitis is associated with EPI, DM, or both in a high percentage of patients with IgG4-RD. While symptomatic acute pancreatitis may not be common, patient-reported symptom burden due to IgG4-related autoimmune pancreatitis or its complications is greater than previously appreciated.