title: Late primary autoimmune hypothyroidism in a patient with postdelivery autoimmune hypopituitarism associated with antibodies to growth hormone and prolactin-secreting cells.
abstract: BACKGROUND
  Pituitary and thyroid autoimmunity can be triggered by pregnancy. We report the first association of combined growth hormone (GH) and prolactin secretion deficiency due to autoimmune damage to GH- and prolactin-secreting cells in a patient with postdelivery lactation failure, presenting subsequently with primary autoimmune hypothyroidism.
  
  
  METHODS
  A 34-year-old woman presented with lactation failure following the delivery of her first child. She had a family history of hypothyroidism without a history of pituitary dysfunction. Physical examination did not show any abnormal findings. Laboratory investigations showed normal gonadotropin levels after the restoration of normal menstrual cycles following pregnancy, normal basal and stimulated cortisol levels, but an impaired GH response to insulin-induced hypoglycemia, and low basal prolactin and insulin-like growth factor-1 concentrations. Thyroid function was normal when initially investigated three months after delivery, but five months later, marked primary hypothyroidism (thyrotropin levels >100 mIU/L) occurred. Immunological investigation revealed the presence of antipituitary antibodies, identified by double immunofluorescence and targeting GH- and prolactin-secreting cells. Antithyroid antibodies, in the normal range three months postpartum, became significantly elevated when the hypothyroidism appeared. Autoimmune hypophysitis is responsible for selective or multiple pituitary-hormone deficiencies, sometimes involving thyrotropin secretion and causing secondary hypothyroidism, but usually associated with hyperprolactinemia. To our knowledge, this is the first observation of autoimmune hypopituitarism involving deficient growth hormone and prolactin secretion in a patient with lactation failure after delivery, subsequently followed by severe primary autoimmune hypothyroidism, thus falling into an unusual constellation of autoimmune polyendocrine syndrome type 3.
  
  
  CONCLUSIONS
  Considering the well-known relationship between pregnancy and autoimmunity, an early postdelivery immunological and functional investigation in women presenting with disorders of lactation may be useful to detect potential pituitary and thyroid dysfunction even at a subclinical stage.
authors.affiliation: Department of Cardiothoracic and Respiratory Sciences, Section of Endocrinology, Faculty of Medicine and Surgery, Second University of Naples, Naples, Italy. annamaria.debellis@uninaz.it
authors.forename: Annamaria
authors.initials: A
authors.lastname: De Bellis
authors.forename: Caterina
authors.initials: C
authors.lastname: Colella
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellastella
authors.forename: Emma
authors.initials: E
authors.lastname: Lucci
authors.forename: Antonio Agostino
authors.initials: AA
authors.lastname: Sinisi
authors.forename: Antonio
authors.initials: A
authors.lastname: Bizzarro
authors.forename: Ian
authors.initials: I
authors.lastname: Holdaway
mesh_terms: D000328:Adult; D005260:Female; D030342:Genetic Diseases, Inborn / Q000276:immunology*; D050031:Hashimoto Disease / Q000276:immunology*; D019382:Human Growth Hormone / Q000172:deficiency / Q000276:immunology*; D006801:Humans; D007249:Inflammation / Q000276:immunology; D007775:Lactation Disorders / Q000276:immunology*; D010900:Pituitary Diseases / Q000276:immunology; D010902:Pituitary Gland / Q000276:immunology; D011247:Pregnancy; D011388:Prolactin / Q000172:deficiency* / Q000276:immunology / Q000378:metabolism; D013967:Thyroiditis, Autoimmune
chemical_list: D019382:Human Growth Hormone; D011388:Prolactin