Risk of carcinoma in IgG4-associated autoimmune pancreatitis – a single center experience

Introduction: Immunoglobulin G4-associated pancreatitis has been recently regarded as a novel and challenging entity. This disease is part of a complex autoimmune disorder with multi-organic involvement characterized with IgG4-positive plasmacytic infiltration of various tissues and organs with consequent sclerosis which responds excellent to steroid therapy. Most commonly affected organs are the pancreas in sense of autoimmune pancreatitis (AIP) and biliary tract, the so called autoimmune cholangitis (AIC). It is suggested that patients may be at risk to develop malignancies since AIP shares a number of clinical, biochemical, and imaging features with pancreas- and cholangiocarcinoma (CCA).

Patients and methods: We therefore retrospectively analyzed 30 patients treated at our Department between 2010 and 2015 who fulfilled the international diagnostic criteria for AIP and compared patients with type 1 autoimmune pancreatitis (AIP1) with patients diagnosed with type 2 autoimmune pancreatitis (AIP2) and defined characteristics which may promote the development of carcinoma.

Results: The majority of our patients suffered from AIP2 (53.3%). Patients with AIP1 were significantly older (mean age 57.1 ± 4.8 years) than those with AIP2 (mean age 45.2 ± 3.0 years, p < 0.05). The majority in AIP1 was male (71.4%) while AIP2 patients were mostly of female gender (62.5%). Moreover, 78.6% of the AIP1 patients had concurrent autoimmune cholangitis (AIC) while 18.8% of the AIP2 patients suffered from ulcerative colitis (UC). We found 2 patients in the AIP1 group who developed CCA. However, in the AIP2 group 1 patient was diagnosed with CCA and 1 patient suffered from hepatocellular carcinoma (HCC).

Conclusion: AIP has gained increased attention worldwide. Awareness of this disease is essential to avoid delays in diagnosing malignancies. Therefore, it is of primary clinical importance to closely survey these patients.