title: The prevalence of IgG4-related hypophysitis in 170 consecutive patients with hypopituitarism and/or central diabetes insipidus and review of the literature.
abstract: OBJECTIVE
  The prevalence and clinical characteristics of IgG4-related hypophysitis remain unclear due to the limited number of case reports. Therefore, in this study, we screened consecutive outpatients with hypopituitarism and/or diabetes insipidus (DI) to estimate its prevalence.
  
  
  METHODS
  A total of 170 consecutive outpatients with hypopituitarism and/or central DI were screened at Kobe University Hospital for detecting IgG4-related hypophysitis by pituitary magnetic resonance imaging, measuring serum IgG4 concentrations, assessing the involvement of other organs, and carrying out an immunohistochemical analysis to detect IgG4-positive cell infiltration.
  
  
  RESULTS
  Among the screened cases, 116 cases were excluded due to diagnosis of other causes such as tumors and congenital abnormalities. Additionally, 22 cases with isolated ACTH deficiency were analyzed and were found not to meet the criteria of IgG4-related hypophysitis. The remaining 32 cases were screened and seven were diagnosed with IgG4-related hypophysitis, of which three cases were diagnosed by analyzing pituitary specimens. IgG4-related hypophysitis was detected in 30% (seven of 23 patients) of hypophysitis cases and 4% of all hypopituitarism/DI cases. The mean age at the onset of IgG4-related hypophysitis was 61.8±8.8 years, and the serum IgG4 concentration was 191.1±78.3 mg/dl (normal values 5-105 mg/dl and values in IgG4-related disease (RD) ≥135 mg/dl). Pituitary gland and/or stalk swelling was observed in six patients, and an empty sella was observed in one patient. Multiple co-existing organ involvement was observed in four of the seven patients prior to the onset of IgG4-related hypophysitis.
  
  
  CONCLUSIONS
  These data suggest that the prevalence of IgG4-related hypophysitis has been underestimated. We should also consider the possibility of the development of hypopituitarism/DI caused by IgG4-related hypophysitis during the clinical course of other IgG4-RDs.
authors.affiliation: Division of Diabetes and Endocrinology, Department of Internal Medicine.
authors.forename: Hironori
authors.initials: H
authors.lastname: Bando
authors.forename: Genzo
authors.initials: G
authors.lastname: Iguchi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Fukuoka
authors.forename: Masaaki
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Ryusaku
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Kentaro
authors.initials: K
authors.lastname: Suda
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nishizawa
authors.forename: Michiko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Eiji
authors.initials: E
authors.lastname: Kohmura
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D020790:Diabetes Insipidus, Neurogenic / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007018:Hypopituitarism / Q000453:epidemiology*; D007074:Immunoglobulin G / Q000097:blood; D007249:Inflammation / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000453:epidemiology*; D015995:Prevalence
chemical_list: D007074:Immunoglobulin G