Diabetes as First Manifestation of Autoimmune Pancreatitis

Abstract

Autoimmune pancreatitis (AIP) is a distinct form of pancreatitis that presents with nonspecific symptoms, such as mild abdominal pain, general fatigue or obstructive jaundice, diffuse or localized enlargement of the pancreas on imaging tests and good response to steroids. AIP is categorized into 2 subtypes, type 1 and type 2. 1 Kanno A. Masamune A. Okazaki K. Nationwide epidemiological survey of autoimmune pancreatitis in Japan in 2011. Pancreas. 2015; 44: 535-539 Crossref PubMed Scopus (119) Google Scholar Type 1 AIP is associated with multiorgan involvement, named immunoglobulin G4 (IgG4)-related disease, whereas type 2 AIP is a pancreas-specific disorder with no relation to IgG4. 1 Kanno A. Masamune A. Okazaki K. Nationwide epidemiological survey of autoimmune pancreatitis in Japan in 2011. Pancreas. 2015; 44: 535-539 Crossref PubMed Scopus (119) Google Scholar Almost all cases of AIP in Japan are type 1, and the prevalence rate is 4.6 per 100,000 individuals in Japan. 1 Kanno A. Masamune A. Okazaki K. Nationwide epidemiological survey of autoimmune pancreatitis in Japan in 2011. Pancreas. 2015; 44: 535-539 Crossref PubMed Scopus (119) Google Scholar In contrast, type 2 AIP is more common in the United States. 1 Kanno A. Masamune A. Okazaki K. Nationwide epidemiological survey of autoimmune pancreatitis in Japan in 2011. Pancreas. 2015; 44: 535-539 Crossref PubMed Scopus (119) Google Scholar The symptoms of type 1 AIP are nonspecific, and the most common symptoms are obstructive jaundice, mild abdominal pain or discomfort, body weight loss and anorexia (Table). It is seen that 15% of type 1 AIP cases are asymptomatic. 2 Okazaki K. Kawa S. Kamisawa T. Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 I. Concept and diagnosis of autoimmune pancreatitis. J Gastroenterol. 2014; 49: 567-588 Crossref PubMed Scopus (81) Google Scholar Laboratory data demonstrated elevated hepatic enzyme levels in 60-82% and elevated bilirubin levels in 39-62% of patients with type 1 AIP. 2 Okazaki K. Kawa S. Kamisawa T. Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 I. Concept and diagnosis of autoimmune pancreatitis. J Gastroenterol. 2014; 49: 567-588 Crossref PubMed Scopus (81) Google Scholar Although pancreatic enzymes are elevated in 36-64% of patients, the levels rarely become extremely high. 2 Okazaki K. Kawa S. Kamisawa T. Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 I. Concept and diagnosis of autoimmune pancreatitis. J Gastroenterol. 2014; 49: 567-588 Crossref PubMed Scopus (81) Google Scholar TABLEClinical symptoms in autoimmune pancreatitis. (Reproduced from Okazaki et al 2 Okazaki K. Kawa S. Kamisawa T. Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 I. Concept and diagnosis of autoimmune pancreatitis. J Gastroenterol. 2014; 49: 567-588 Crossref PubMed Scopus (81) Google Scholar with permission from the Japanese Society of Gastroenterology.) Clinical symptoms in AIP % Obstructive jaundice 33-59 Abdominal pain 32 Back pain 15 Body weight loss 15 Anorexia 9 General fatigue 9 Abnormal stool 7 Fever 6 No symptoms 15 AIP, autoimmune pancreatitis. Open table in a new tab AIP, autoimmune pancreatitis.