Crohnʼs disease complicated by pancreatic atrophy

Abstract

Crohn's disease is an immunodysregulatory disorder. We report a case of a common bile duct stricture followed by pancreatic atrophy complicating Crohn's disease in a pediatric patient. A 13 year-old presented with chronic postprandial right upper quadrant pain, decreased oral intake, and five-day history of bloody formed stools. Initial labs showed direct bilirubin of 0.8 (<0.1 mg/dl), ALT 176 (<63 IU/L), AST 88 (<55 IU/ L), GGT 446 (<45 IU/L), and lipase 65 (<30 U/L). ESR was 43 (<20 mm/h) and albumin was 3.3 (>3.5 g /dl). Amylase, CBC, and INR were normal. ERCP showed a distal stricture with a 12 mm proximal dilatation of the common bile duct. Pancreaticogram was normal. She was treated with a sphincterotomy and stent placement. Ductal brushings were remarkable for reactive changes, neutrophils, pancytokeratin positive epithelium trapped in fibrous tissue. There was no dysplasia or positive IgG4 staining. An abdominal CT scan was normal. Sclerosing cholangitis was suspected and subsequent colonoscopy showed mildto- moderate granulomatous pancolitis. She went in remission with steroids, and maintained on mesalamine, and ursodeoxycholic acid. Workup was notable for weakly positive ASCA IgG and negative ANA, antismooth muscle, anti liver-kidney microsomal antibodies. Total IgG and IgG4 were normal. Her pain and liver enzymes normalized within 6 weeks. Three months later a repeat ERCP with stent removal showed stricture resolution. Six months later she was admitted with weight loss, hematochezia, and periumbilical abdominal pain. Labs showed CRP 15 (<0.81 mg/dl), ESR 33, and albumin 3.1. Her liver and pancreatic enzymes were normal. Colonoscopy showed severe colitis which responded to a steroid burst and 6-mercaptopurine was added. MRCP at that time showed marked pancreatic atrophy not previously seen in the initial abdominal CT but normal biliary and pancreatic ducts. She had a normal PRSS-1, SPINK-1, and CFTR genotype. Her fecal elastase, Hemoglobin A1C, vitamins A and D, and pancreatic enzymes in duodenal aspirate were all normal. Due to slightly low Vitamin E levels, fat soluble vitamins were started. The differential diagnosis for pancreatic atrophy includes autoimmune pancreatitis (AIP), cystic fibrosis, hereditary pancreatitis and chronic pancreaticobiliary ductal obstruction. The constellation of findings supported a diagnosis of Type II autoimmune pancreatitis (AIP) associated with Crohn's disease. Type II AIP is seen in females during the 3rd decade of life, has an association with IBD, and occasionally can have biliary duct strictures with negative IgG4 staining. AIP is steroid responsive but 30-50% of patients relapse after initial steroid therapy. Maintenance options include chronic low dose steroids or thiopurines. Diabetes mellitus can develop in 60-70% of cases. There is no causal link to pancreatic cancer. In summary, we report a pediatric patient presenting with a CBD stricture and suspected sclerosing cholangitis who was then diagnosed with Crohn's disease. Subsequently she developed pancreatic atrophy most likely secondary to Type II AIP. Unique features include normal amylase and lipase on initial presentation, absence of pancreatic enlargement, and rapid pancreatic atrophy within six months of presentation.