title: A new criteria for screening macroprolactinemia using polyethylene glycol treatment combined with different assays for prolactin.
abstract: To establish the criteria for screening macroprolactinemia (MP) after Polyethylene glycol (PEG) treatment plus different assays of Prolactin (PRL) in a clinical setting.
  
  
  
  This study recruited 122 patients, and their PRL-elevated serum samples were collected. Twenty-two of the 122 serum samples were treated by gel filtration chromatography (GFC) and PEG precipitation. The PRL content in the eluent and supernatant were tested separately by two analyzers: i2000sr (Abbott Laboratories, Chicago, IL, USA) and E170 (Roche Diagnostics, Basel, Switzerland). The GFC-method (the gold standard) was applied, in order to establish the criteria of screening MP after PEG-method. The MP positive rate and PRL concentrations in 100 PRL-elevated patients were compared between the literature criteria (a PRL recovery of < 40%) and the new criteria.
  
  
  
  The detected value of macroprolactin with the new criteria in the i2000sr (a PRL recovery of < 50%) was higher than in the E170 (a PRL recovery of < 60%). The E170 analyzer detected 38 cases of MP in 100 PRL-elevated samples by using new criteria, which was higher than the literature criteria (24 cases) (p < 0.05). Therefore, there were 15 samples could not be judged consistently using the literature criteria by the i2000sr and E170 analyzers. There was also a significant difference in PRL concentrations between the two groups (p < 0.01). If using the new criteria, the inconsistency between the two analyzers was reduced to 2 samples. There was a very significant difference in the inconsistency between two criteria (p < 0.01). The reported values of PRL from the i2000sr and E170 were 27.8 (16.2-42.6) ng/ml and 32.0 (19.6-49.9) ng/ml. There were no significant differences between two analyzers.
  
  
  
  Establishment of different criteria for screening MP by using PEG-method is helpful for the accuracy of PRL determination and its comparability.
authors.affiliation: Laboratory Medicine Center, Zhejiang Provincial People's Hospital, Hangzhou, China.
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Chen
authors.forename: G-Z
authors.initials: GZ
authors.lastname: Song
authors.forename: Z-N
authors.initials: ZN
authors.lastname: Wang
mesh_terms: D002850:Chromatography, Gel; D006801:Humans; D006966:Hyperprolactinemia / Q000175:diagnosis*; D011092:Polyethylene Glycols / Q000737:chemistry; D011388:Prolactin / Q000097:blood*
chemical_list: C060678:prolactin, polymeric; D011092:Polyethylene Glycols; D011388:Prolactin