title: [Macroprolactinemia identification in patients with hyperprolactinemia].
abstract: BACKGROUND
  Macroprolactinemia is defined as hyperprolactinemia with predominance of the big-big prolactine isoform. Its frequency has not been clearly established due to technical difficulties to identify it. This method used to detect it is gel filtration chromatography, an expensive and complicated procedure that could not be used routinely.
  
  
  OBJECTIVE
  To validate the PEG precipitation technique, to identify the presence of macroprolactinemia and to correlate it with the clinical characteristics in a group of pre-selected patients with elevated serum PRL levels from different causes.
  
  
  METHODS
  There were studied 14 patients non pre-selected with high PRL serum levels. Prolactine levels were determined with commercial immunometric quimioluminescence essays. All the essays were duplicated, and healthy patients serum (without hyperprolactinemia) were used. Technique consists on mixing 250 microL of serum with the same volume of polyethylene glycol. Later it was centrifugated at 3000 rpm during 30 minutes at 4 degrees C. Prolactine level was measured in supernatant.
  
  
  RESULTS
  Within patients 7 to 14 macroprolactinemia was ruled out and confirmed truth hyperprolactinemia, some times slight and nontumoral, some times mild, and some times due to prolactin-producer hypophysial macroadenomas.
  
  
  CONCLUSIONS
  Polyethylene glycol precipitation technique is reliable to detect macroprolactinemia.
authors.affiliation: Servicio de endocrinologia, Unidad de Investigación Médica en Endocrinologia Experimental, México.
authors.forename: Carolina
authors.initials: C
authors.lastname: Sandoval
authors.forename: Baldomero
authors.initials: B
authors.lastname: González
authors.forename: Sonia
authors.initials: S
authors.lastname: Cheng
authors.forename: Yoshua
authors.initials: Y
authors.lastname: Esquenazi
authors.forename: Moisés
authors.initials: M
authors.lastname: Mercado
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods; D006801:Humans; D006966:Hyperprolactinemia / Q000097:blood*; D008970:Molecular Weight; D010865:Pilot Projects; D011092:Polyethylene Glycols; D011388:Prolactin / Q000097:blood*
chemical_list: C060678:prolactin, polymeric; D011092:Polyethylene Glycols; D011388:Prolactin