title: Macroprolactinaemia associated with prolactin adenoma.
abstract: BACKGROUND
  Macroprolactinaemia, defined as hyperprolactinaemia with a predominance of, or only, the big big prolactin (bbPRL) isoform, is considered idiopathic and poorly symptomatic. Since its association with a PRL adenoma is poorly documented, we examined a series of 13 patients with tumoral hyperprolactinaemia for the presence of macroprolactinaemia.
  
  
  METHODS
  From a series of 36 patients with hyperprolactinaemia studied for PRL isoforms, we selected 13 with hyperprolactinaemia and a prolactinoma, and divided them into two groups on the basis of the predominant PRL isoform, the large PRL group (five patients), with a predominance of the big big PRL isoform, and the monomeric PRL (mPRL) group (eight patients), with a predominance of the mPRL isoform. Plasma PRL concentrations were measured by radioimmunoassay, while plasma PRL heterogeneity was studied by gel filtration chromatography. The plasma autoantibody-bound PRL and the histology of the tumours were also studied.
  
  
  RESULTS
  Macroprolactinaemia was seen in five out of the 13 patients with a PRL adenoma. The clinical and biological characteristics of the groups with and without macroprolactinaemia were similar. In the large PRL group, no evidence for anti-PRL autoantibodies was found and the prolactinomas were either typical or exhibited unusual aggregates of immunoreactive PRL deposits, the latter suggesting the tumoral origin of these large forms.
  
  
  CONCLUSIONS
  Our results suggest that PRL adenoma may be associated with macroprolactinaemia.
authors.affiliation: Service d'Endocrinologie, Hôpital Bellevue, 42055 Saint-Etienne Cedex 2, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Mounier
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Trouillas
authors.forename: Bruno
authors.initials: B
authors.lastname: Claustrat
authors.forename: Robert
authors.initials: R
authors.lastname: Duthel
authors.forename: Bruno
authors.initials: B
authors.lastname: Estour
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000097:blood* / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D015994:Incidence; D008297:Male; D008599:Menstruation Disturbances / Q000209:etiology; D010911:Pituitary Neoplasms / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D011388:Prolactin / Q000097:blood* / Q000378:metabolism; D015175:Prolactinoma / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D020033:Protein Isoforms / Q000097:blood
chemical_list: D020033:Protein Isoforms; C060678:prolactin, polymeric; D011388:Prolactin