title: Macroprolactinemia: the consequences of a laboratory pitfall.
abstract: The objective of this study was to assess the prevalence of macroprolactin, a macromolecule with reduced bioactivity, in hyperprolactinemic patients. Prolactin was measured before and after precipitation of macroprolactin by polyethylene glycol in 306 patients. Only patients with prolactin values >700 mIU/L (n = 270) entered the study. In 23% of the patients, macroprolactinemia was found. In women, the occurrence of macroprolactinemia increased with advancing age (< 30 yr: 16%; 30-45 yr: 28%; > 45 yr: 42%; p < 0.05). A priori clinical signs of hyperprolactinemia (morphological abnormalities in pituitary imaging, galactorrhea infertility) occurred significantly less frequently in macroprolactinemia than in true hyperprolactinemia. In eight females macroprolactinemia and true hyperprolactinemia appeared simultaneously. To avoid diagnostic and therapeutic pitfalls, the screening for macroprolactinemia of all patients with prolactin levels of > 700 mIU/ L is recommended.
authors.affiliation: Central Laboratory, Markusovszky Teaching Hospital of County Vas, Szombathely, Hungary.
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Toldy
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Löcsei
authors.forename: István
authors.initials: I
authors.lastname: Szabolcs
authors.forename: Miklós I
authors.initials: MI
authors.lastname: Góth
authors.forename: Pál
authors.initials: P
authors.lastname: Kneffel
authors.forename: Dominika
authors.initials: D
authors.lastname: Szöke
authors.forename: Gábor L
authors.initials: GL
authors.lastname: Kovács
mesh_terms: D000328:Adult; D002648:Child; D005260:Female; D005590:Fractional Precipitation; D006801:Humans; D006966:Hyperprolactinemia / Q000097:blood* / Q000175:diagnosis; D008163:Luminescent Measurements; D008297:Male; D011092:Polyethylene Glycols / Q000737:chemistry; D011388:Prolactin / Q000097:blood*; D012189:Retrospective Studies
chemical_list: C060678:prolactin, polymeric; D011092:Polyethylene Glycols; D011388:Prolactin