Autoimmune pancreatitis with spontaneous remission on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

Abstract

A 79-year-old man with elevated blood glucose was started on insulin therapy. IgG4 was as high as 1,830 mg/dL, and 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) confirmed diffuse pancreatic enlargement and accumulation of FDG. Based on the above, autoimmune pancreatitis (AIP) was diagnosed, but steroid treatment was not performed. IgG4 later declined, and FDG accumulation in the pancreas disappeared on FDG-PET/CT at the age of 83 years. AIP was thought to have gradually remitted spontaneously over time. FDG-PET/CT is useful for evaluating AIP activity.

Case Details

Disease Location

Pancreas

Personal Characteristics

79-year-old man. Family history of pulmonary tuberculosis and angina pectoris. At the age of 67, the patient received coronary angioplasty and coronary artery bypass due to acute myocardial infarction. In the same year, he underwent clipping for an unruptured cerebral aneurysm. He was diagnosed with diabetes at age 68, and at 72, he developed high blood pressure and hyperlipidemia. He was treated with aspirin 100 mg/day, amlodipine 5 mg/day, warfarin 2.75 mg/day, acarbose 0.6 mg/day, pioglitazone 15 mg/day, and ethyl icosapentate acid 1,800 mg/day.

Clinical Characteristics

Reported dry mouth and weight loss. He was hospitalized because his blood glucose control deteriorated. Aspirin 100 mg/day, warfarin 1 mg/day, sarpogrelate 100 mg/day, telmisartan 40 mg/hydrochlorothiazide 12.5 mg combination tablet/day, adenosine triphosphate 600 mg/ day, mitiglinide 10 mg/voglibose 0.2 mg combination tablet (3 tablets/day), gliclazide 20 mg/day, mecobalamin 1,500 mg/day, ezetimibe 10 mg/day, and alogliptin 25 mg/pioglitazone 30 mg combination tablet/day were administered on admission. Serum total protein and γ-globulin levels were increased. IGG was increased in the γ-globulin fraction; igg1, IGG 2, IGG 3, and igg4 subtypes were increased, but igg4 was particularly high. Diabetic complications included simple retinopathy and mild neuropathy, but no nephropathy. After hospitalization, mitiglinide/voglibose, gliclazide, and pioglitazone/alogliptin were discontinued. The patient was prescribed 4 u of insulin aspart immediately before breakfast, just before lunch, and just before dinner. Before bed, 6 u of insulin detemir was prescribed. Insulin aspart was gradually increased to 13 u immediately before breakfast, 12 u just before lunch, and 11 u just before dinner. This regimen improved blood glucose control. As igg4 was high, autoimmune pancreatitis was suspected, and imaging tests were performed. Magnetic resonance cholangiopancreatography revealed stenosis of the main pancreatic duct at the head of the pancreas. The common bile duct narrowed at the area penetrating the pancreatic head. Diffuse enlargement of the pancreas and accumulation of fdg were observed on fdg-PET/CT. Right subclavian, abdominal periaortic, subdiaphragmatic, iliac, and inguinal lymph nodes were enlarged, and fdg accumulation was observed. Imaging findings were consistent with autoimmune pancreatitis.

Remission Characteristics

Swelling of the pancreas disappeared on abdominal CT at age 83. Serum igg4 gradually decreased

Treatment & Mechanisms

Clinical Treatment

Aspirin 100 mg/day, warfarin 1 mg/day, sarpogrelate 100 mg/day, telmisartan 40 mg/hydrochlorothiazide 12.5 mg combination tablet/day, adenosine triphosphate 600 mg/ day, mitiglinide 10 mg/voglibose 0.2 mg combination tablet (3 tablets/day), gliclazide 20 mg/day, mecobalamin 1,500 mg/day, ezetimibe 10 mg/day, and alogliptin 25 mg/pioglitazone 30 mg, insulin