title: Characterization of antipituitary antibodies targeting pituitary hormone-secreting cells in idiopathic growth hormone deficiency and autoimmune endocrine diseases.
abstract: OBJECTIVE
  In order to investigate whether somatotrophs are the target of antipituitary antibodies (APA) in adult patients with growth hormone deficiency (GHD), we studied the sera of 37 APA positive patients.
  
  
  METHODS
  Patients were grouped as follows: nine patients with APA at high titre (> 1 : 8) affected by apparently idiopathic GHD; four of them (group 1a) with isolated GHD diagnosed during childhood and five with GHD diagnosed during adulthood associated with autoimmune endocrine diseases (group 1b), and 28 patients with autoimmune endocrine diseases without pituitary impairment, previously found positive for APA at low titre (1 : 8, group 2).
  
  
  METHODS
  APA were evaluated by a four-layer double indirect immunofluorescence technique.
  
  
  RESULTS
  In group 1a patients, APA immunostained exclusively GH-producing cells. In group 1b patients, APA were directed not only to GH- but also to other pituitary hormone-producing cells. In group 2 patients, APA were directed selectively to PRL-producing cells and rarely to some GH-producing cells.
  
  
  CONCLUSIONS
  In the present study, we demonstrated that GH-secreting cells are the target of the autoimmune reaction in autoimmune GHD and that the immunostaining of only the somatotrophs is typical of isolated GHD. In contrast, the finding of diffuse staining of APA indicates the need to search for other autoimmune diseases. Finally, the presence of APA at low titre directed against PRL-secreting cells in patients with autoimmune endocrine diseases in the absence of pituitary impairment, seems to be only a nonspecific marker of pituitary autoimmunity. A longitudinal study would be useful to clarify the relationship between the different pituitary cell involvement and the natural history of pituitary dysfunction in autoimmune hypophysitis.
authors.affiliation: Chair of Endocrinology, Department of Clinical and Experimental Medicine and Surgery F. Magrassi and A. Lanzara - Second University of Naples, 80131, Naples, Italy. annamaria.debellis@unina2.it
authors.forename: Annamaria
authors.initials: A
authors.lastname: De Bellis
authors.forename: Antonio
authors.initials: A
authors.lastname: Bizzarro
authors.forename: Silvia
authors.initials: S
authors.lastname: Perrino
authors.forename: Concetta
authors.initials: C
authors.lastname: Coronella
authors.forename: Marisa
authors.initials: M
authors.lastname: Conte
authors.forename: Daniela
authors.initials: D
authors.lastname: Pasquali
authors.forename: Antonio Agostino
authors.initials: AA
authors.lastname: Sinisi
authors.forename: Corrado
authors.initials: C
authors.lastname: Betterle
authors.forename: Antonio
authors.initials: A
authors.lastname: Bellastella
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D004700:Endocrine System Diseases / Q000276:immunology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D008297:Male; D010902:Pituitary Gland / Q000276:immunology; D010907:Pituitary Hormones / Q000276:immunology*; D011388:Prolactin / Q000276:immunology
chemical_list: D001323:Autoantibodies; D010907:Pituitary Hormones; D019382:Human Growth Hormone; D011388:Prolactin