Type 1 Autoimmune Pancreatitis Unmasked by COVID-19 Vaccine

Autoimmune pancreatitis is a rare fibro-inflammatory disease with 2 distinct subtypes of which each has their own clinical presentation, risk factors, and histopathological patterns. We present a case of newly diagnosed type 1 autoimmune pancreatitis in a symptomatic 54-year-old man with stable ulcerative colitis 1 month after COVID-19 vaccination. Previous reports have indicated that vaccinations can trigger autoimmune disease in predisposed individuals. This case discusses the occurrence of autoimmune pancreatitis triggered after COVID-19 vaccination.

A case of high-grade pancreatic intraepithelial neoplasia concomitant with type 1 autoimmune pancreatitis: The process underlying both conditions

We report a case of high-grade pancreatic intraepithelial neoplasia (PanIN) concomitant with lymphoplasmacytic sclerosing pancreatitis. The patient was an 82-year-old man in whom narrowing of the main pancreatic duct was detected incidentally by abdominal ultrasonography. Magnetic resonance cholangiopancreatography further revealed abrupt narrowing plus distal dilatation of the duct, from the pancreatic body to the tail. Distal pancreatectomy was performed under a preoperative diagnosis of intraductal papillary-mucinous neoplasm. Macroscopic examination of the surgical specimen showed an ill-demarcated, white-gray area and prominent pancreatic atrophy, while histological analysis detected small (<5 mm in diameter) cystic dilatations of the main pancreatic duct and some branch ducts plus pancreatic atrophy with fibrosis and fatty replacement of acinar cells. We also detected variously sized papillary projections, fused glands, and scattered focal papillary proliferation of columnar ductal epithelium comprising cells with elongated, mildly hyperchromatic nuclei, consistent with high-grade PanIN. In addition, we observed marked lymphoplasmacytic infiltration, periductal storiform fibrosis, and obliterative phlebitis. Immunohistochemical staining revealed abundant immunogloblin G4-positive plasma cells, indicative of type 1 autoimmune pancreatitis (AIP). The coexistence of high-grade PanIN and marked lymphoplasmacytic infiltration, typical of AIP, point to a close association between the former, as a carcinogenic process, and the latter, as an immune response.

Recommendations for Diagnosis and Management of Autoimmune Pancreatitis in Childhood: Consensus From INSPPIRE

OBJECTIVES

Autoimmune pancreatitis (AIP) represents a complex immune-mediated pancreas disorder. Pediatric AIP (P-AIP) is rare. We have recently summarized the characteristic features of P-AIP. We now aim to develop recommendation statements to standardize the diagnostic and therapeutic approach to P-AIP and facilitate future research in the field.

METHODS

A panel of pediatric gastroenterologists participating in the International Study Group of Pediatric Pancreatitis: In search for a cuRE was formed to discuss and then vote on 15 recommendation statements. A consensus of at least 80% was obtained following 3 voting rounds and revision of the statements.

RESULTS

We have now generated 15 statements to help standardize the approach to diagnosis and management of P-AIP.

CONCLUSIONS

The first P-AIP recommendation statements developed by the International Study Group of Pediatric Pancreatitis: In search for a cuRE group are intended to bring standardization to the diagnosis and treatment of this rare childhood disorder. These statements may help guide a uniform approach to patient care and facilitate future research studies.

Autoimmune Pancreatitis Type 2: Case Report

A middle-aged man presents with acute pancreatitis of unknown etiology and is found to have a presentation consistent with the diagnosis of type 2 autoimmune pancreatitis (AIP). AIP is a group of rare heterogeneous diseases that are challenging to diagnose. There are 2 types of AIP. Type 1 disease is the more common worldwide than type 2 AIP. While type 1 AIP is associated with IgG4-positive antibodies, type 2 AIP is IgG4 antibody negative. Both types of AIP are responsive to corticosteroid treatment. Although type 1 AIP has more extrapancreatic manifestations and more commonly relapses, this is a case of a patient with type 2 AIP with inflammatory bowel disease and relapsing course.

Mass-forming type 1 autoimmune pancreatitis mimicking pancreatic cancer

We reported three cases of mass-forming type 1 autoimmune pancreatitis (AIP) that were preoperatively suspected to be pancreatic cancer, and reviewed their clinicopathological features. Radiological findings in the patients revealed hypoattenuating masses in the early phase or a stricture of the main pancreatic duct with upstream dilatation, which was consistent with the diagnosis of pancreatic cancer. Histopathologically, the lesions were well demarcated and met all diagnostic criteria for immunoglobulin G4 (IgG4)-related AIP, including the presence of periductal lymphoplasmacytic infiltration, obliterative phlebitis, storiform fibrosis and abundant IgG4-positive plasma cells. However, the adjacent uninvolved pancreatic duct and lobular structures were well preserved. And in all patients, none or some of the aforementioned characteristics were observed. We suggest that some cases of focal AIP may progress to more severe grades and exhibit mass formation, although remaining localized. These focal cases of AIP are difficult to distinguish from pancreatic cancer. To our knowledge, this report is the first to present a histopathological comparison of mass-forming AIP with the adjacent uninvolved pancreatic tissues.