Autoimmune pancreatocholangitis, non-autoimmune pancreatitis and primary sclerosing cholangitis: a comparative morphological and immunological analysis.
BACKGROUND
Autoimmune pancreatocholangitis (AIPC) is an emerging, not completely characterized disease. Aim of this study was the comprehensive evaluation of a series of AIPC patients, who were diagnosed and treated in a European institution between January 2003 and July 2006.


RESULTS
Thirty-three patients with histologically confirmed AIPC were analyzed and compared to 20 patients with non-autoimmune chronic pancreatitis (CP) and 14 patients with primary sclerosing cholangitis (PSC). Clinical features and conventional histopathology were taken into account. Immunohistochemistry and real-time quantitative PCR were used for the characterization of the inflammatory infiltrate and the stromal reaction. AIPC was localized in the pancreatic head in 94% of the patients. Intra- and/or extrapancreatic biliary tract involvement was present in 64% of the cases. The number of infiltrating T-lymphocytes, macrophages and total plasma cells was significantly higher in AIPC than in CP (3-, 4- and 8-fold increase, respectively). The absolute number of IgG4-positive plasma cells was higher in AIPC than in CP and PSC (7-fold and 35-fold increase, respectively), but significance was only reached in comparison with PSC. CXCR5- and CXCL13-positive cells were almost exclusively detected in AIPC.


CONCLUSIONS
AIPC is mainly a disease of the pancreatic head with possible extension into the periphery of the gland and/or into the biliary tract/gallbladder. The morphology of AIPC, as well as the immune- and stromal reaction is characteristic and comparable between cases with and without biliary tract involvement. Immunological markers (IgG4, CXCR5, CXCL13) can be of diagnostic relevance in specific settings.
Esposito
Irene
I
Institute of Pathology, Technische Universität München, Munich, Germany. irene.esposito@helmholtz-muenchen.de
Born
Diana
D
Bergmann
Frank
F
Longerich
Thomas
T
Welsch
Thilo
T
Giese
Nathalia A
NA
Büchler
Markus W
MW
Kleeff
Jörg
J
Friess
Helmut
H
Schirmacher
Peter
P
D000328:Adult; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology*; D002761:Cholangitis / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology*; D015209:Cholangitis, Sclerosing / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000175:diagnosis* / Q000276:immunology* / Q000473:pathology*; D050500:Pancreatitis, Chronic / Q000276:immunology