Testing for Anti-PBP Antibody Is Not Useful in Diagnosing Autoimmune Pancreatitis.
Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis, clinically mimicking pancreatic cancer. In 2009, a serological diagnostic test detecting antibodies against plasminogen-binding protein (PBP) of Helicobacter pylori was reported with outstanding test performances (NEJM 361:135). We aimed to validate these findings.



Between March 2007 and May 2011, sera were collected from consecutive patients presenting with type 1 AIP, pancreatic ductal adenocarcinoma (PDAC), chronic pancreatitis (CP), primary sclerosing cholangitis (PSC), and healthy controls (HC) with or without antibodies against H. pylori. Serum antibody binding to synthetic PBP peptide was quantified by enzyme-linked immunosorbent assay (ELISA), using standard curves of custom-made PBP rabbit polyclonal antibodies. A synthetic Flag peptide (DYKDDDK), to which no antibodies are found in human serum, was included as negative control.



High sensitivity of PBP peptide recognition was demonstrated by selective binding of PBP peptide over Flag peptide by PBP-immunized rabbit serum. Competition assays with PBP peptide validated the selectivity for antibodies recognizing this antigen. A total of 114 patients were subsequently tested: 34 AIP, 29 PDAC, 17 CP, 16 PSC, and 18 HCs (9 positive and 9 negative for H. pylori). No significant differences in detection of antibodies against the PBP peptide were found between different the patient groups and healthy controls.



Using a sensitive and selective ELISA-based assay, we did not find increased serum antibodies against PBP peptide in AIP patients. PBP serum antibodies are therefore not a useful diagnostic tool to diagnose AIP.
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Jorie
J
Buijs
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Djuna L
DL
Cahen
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Marianne J
MJ
van Heerde
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.|Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands.
Bettina E
BE
Hansen
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Henk R
HR
van Buuren
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Maikel P
MP
Peppelenbosch
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Gwenny M
GM
Fuhler
Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Marco J
MJ
Bruno
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000276:immunology*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D021441:Carcinoma, Pancreatic Ductal / Q000276:immunology; D002352:Carrier Proteins / Q000276:immunology*; D016022:Case-Control Studies; D015209:Cholangitis, Sclerosing / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000276:immunology; D010195:Pancreatitis / Q000175:diagnosis / Q000276:immunology*; D050500:Pancreatitis, Chronic / Q000276:immunology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; C084529:plasminogen-binding protein, bacteria