title: Antibodies to carbonic anhydrase and IgG4 levels in idiopathic chronic pancreatitis: relevance for diagnosis of autoimmune pancreatitis.
abstract: BACKGROUND
  Increased serum antibodies against carbonic anhydrase II (CA-II Ab) or IgG4 levels have been reported in cases of autoimmune chronic pancreatitis (ACP).
  
  
  OBJECTIVE
  To assess the relevance of serum CA-II Ab and IgG4 levels for the diagnosis of ACP in idiopathic CP (ICP) versus alcoholic CP and Sjogren's syndrome (SS).
  
  
  METHODS
  This was a multicentre study involving 227 subjects divided into four groups: ICP (n = 54), normal controls (n = 54, paired by age and sex with ICP patients), alcoholic CP (n = 86), and SS (n = 33).
  
  
  METHODS
  CA-II Ab was measured by ELISA and confirmed by western blotting. A score of easy clinical use with major clinical, morphological, and biochemical parameters for the diagnosis of ACP was applied.
  
  
  RESULTS
  The percentage of patients with increased serum CA-II Ab was higher in the ICP group (28%) than in controls (1.9%) and in patients with alcoholic CP (10.5%), but lower than in patients with SS (64%). The proportion with elevated IgG4 levels was higher in the ICP group (15%) compared with controls (1.9%) and SS (0%) but not significantly different from alcoholic CP (8%). Most ICP patients (7/8) with high IgG4 levels exhibited increased CA-II Ab and a compatible ACP score. A definitive diagnosis of ACP by histological analysis was associated with other autoimmune disorders, an increase in both serum IgG4 and CA-II Ab levels, and IgG4 positive plasma cells.
  
  
  CONCLUSIONS
  The increase in serum IgG4 levels was strongly associated with elevated CA-II Ab levels, manifestations compatible with ACP, and lymphoplasmacytic infiltration when surgical specimens were available.
authors.affiliation: Unit of Heptatology, University Clinic Hospital, Valencia, Spain. aparisi_lui@gva.es
authors.forename: L
authors.initials: L
authors.lastname: Aparisi
authors.forename: A
authors.initials: A
authors.lastname: Farre
authors.forename: L
authors.initials: L
authors.lastname: Gomez-Cambronero
authors.forename: J
authors.initials: J
authors.lastname: Martinez
authors.forename: G
authors.initials: G
authors.lastname: De Las Heras
authors.forename: J
authors.initials: J
authors.lastname: Corts
authors.forename: S
authors.initials: S
authors.lastname: Navarro
authors.forename: J
authors.initials: J
authors.lastname: Mora
authors.forename: M
authors.initials: M
authors.lastname: Lopez-Hoyos
authors.forename: L
authors.initials: L
authors.lastname: Sabater
authors.forename: A
authors.initials: A
authors.lastname: Ferrandez
authors.forename: D
authors.initials: D
authors.lastname: Bautista
authors.forename: M
authors.initials: M
authors.lastname: Perez-Mateo
authors.forename: S
authors.initials: S
authors.lastname: Mery
authors.forename: J
authors.initials: J
authors.lastname: Sastre
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D024402:Carbonic Anhydrase II / Q000276:immunology*; D002908:Chronic Disease; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D019512:Pancreatitis, Alcoholic / Q000175:diagnosis / Q000276:immunology; D010950:Plasma Cells / Q000276:immunology; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D007074:Immunoglobulin G; D024402:Carbonic Anhydrase II