Diagnosis and management of autoimmune pancreatitis: An analysis of 43 cases

Objective To clarify the clinical characteristics of autoimmune pancreatitis (AIP) and explore the experience of diagnosis and treatment. Methods Clinical data about 43 patients with a diagnosis of AIP in Chinese PLA General Hospital from January 1, 2011 to June 1, 2014 were retrospectively analyzed. Results The ratio of male to female was 4.4:1 with an average age of 57.4±12.0 years old in 43 patients with AIP. Obstructive jaundice was the most frequent initial symptom (58.1%), followed by abdominal discomfort (37.2%) and anorexia (4.7%). More than half of patients were complicated with weight loss (51.2%). The albumin/ globulin ratio of 38 (88.4%) patients’ serum was lower than 1.5, serum amylase increased in 5 cases (11.6%) and serum CA19-9 level above 100 U/ml occurred in 7 patients (16.3%). Serum immunoglobulin G4 levels were elevated in 39 cases (90.7%) and serum gamma globulin levels were elevated in 14 (93.3%) cases. Diffuse swelling of the pancreas was found in 28 patients (65.1%) and segmental swelling of the pancreas in 15 cases (34.9%). The correct rate of diagnosis upon PET/CT was 58.3% (7/12). The incidence of benign disease post-operation for a presumed malignancy was 11.6% (5/43). The remission rate of steroid-treated AIP was 100% and the relapsing rate within 12 months was 14.0% (6/43) without maintenance therapy. Conclusion Combining clinical symptoms, blood test, computed tomography (CT) and magnetic resonance (MR) findings together can effectively increase the correct diagnosis rate of AIP. When a diagnosis of AIP is highly suspected, a biopsy is recommended, and a short course of steroid treatment should be considered if the biopsy does not reveal features suspicious for malignancy. The standard treatment for AIP is steroid therapy.