title: Immunoglobulin G4-related prostatitis: a case-control study focusing on clinical and pathologic characteristics.
abstract: OBJECTIVE
  To evaluate the occurrence and histopathologic characteristics of immunoglobulin G4 (IgG4)-related prostatic involvement in patients diagnosed with autoimmune pancreatitis.
  
  
  METHODS
  Nine cases of IgG4-related prostatitis were identified among 117 men in the autoimmune pancreatitis and IgG4-associated cholangitis patient databases in 2 tertiary hospitals. Clinical information was retrieved, and available prostatic tissue samples and 18 prostatitis control samples were evaluated for characteristic IgG4-related disease (IgG4-RD) features: maximum number of IgG4-positive cells per high-power field; dense lymphoplasmacytic infiltrate; fibrosis, arranged at least focally in a storiform pattern; phlebitis with or without obliteration of the lumen; and increased number of eosinophils.
  
  
  RESULTS
  The aspecific sign of urine retention was commonly present in IgG4-RD patients with prostatic involvement. In these patients with IgG4-related prostatitis, the median number of IgG4-positive cells in prostatic tissue was 150 (interquartile range, 20-150) per high-power field compared with a median of 3 (interquartile range, 1-11) in control patients (P = .008). Dense lymphoplasmacytic infiltrate was observed in most (86% in cases and 72% in control patients) tissue samples independent of the underlying cause of prostatitis. Fibrosis in at least a focally storiform pattern was seen rarely in both groups, and (obliterative) phlebitis was absent in all patients. Furthermore, eosinophil numbers were more often elevated in patients with IgG4-RD compared with controls (P <.001). In 2 cases, amelioration of the prostatitis symptoms on corticosteroid treatment was documented.
  
  
  CONCLUSIONS
  Prostatic involvement might not be rare in patients with pancreatic or biliary IgG4-RD. Clinicians should consider this disease entity in patients with IgG4-RD and prostatic symptoms.
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Jorie
authors.initials: J
authors.lastname: Buijs
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Lucas
authors.initials: L
authors.lastname: Maillette de Buy Wenniger
authors.affiliation: Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Geert
authors.initials: G
authors.lastname: van Leenders
authors.affiliation: Department of Pathology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Joanne
authors.initials: J
authors.lastname: Verheij
authors.affiliation: Department of Urology, Amphia Hospital, Breda, The Netherlands.
authors.forename: Ilze
authors.initials: I
authors.lastname: van Onna
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Bettina
authors.initials: B
authors.lastname: Hansen
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Marianne
authors.initials: M
authors.lastname: van Heerde
authors.affiliation: Department of Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Nanda
authors.initials: N
authors.lastname: Krak
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Beuers
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Marco
authors.initials: M
authors.lastname: Bruno
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands. Electronic address: h.vanbuuren@erasmusmc.nl.
authors.forename: Henk
authors.initials: H
authors.lastname: van Buuren
mesh_terms: D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications / Q000276:immunology*; D016022:Case-Control Studies; D002761:Cholangitis / Q000150:complications / Q000276:immunology; D004804:Eosinophils; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000150:complications / Q000276:immunology; D010950:Plasma Cells / Q000473:pathology; D011467:Prostate / Q000737:chemistry / Q000473:pathology*; D011472:Prostatitis / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D016055:Urinary Retention / Q000209:etiology
chemical_list: D007074:Immunoglobulin G