Review article

Macroprolactinemia: new insights in hyperprolactinemia

Miro Kasum orcid.org/0000-0003-4896-1284 ; Department of Obstetrics and Gynaecology, University Hospital Center, School of Medicine, University of Zagreb, Zagreb, Croatia
Slavko Oreskovic ; Department of Obstetrics and Gynaecology, University Hospital Center, School of Medicine, University of Zagreb, Zagreb, Croatia
Ivana Zec ; Laboratory of Endocrinology, Clinic of Oncology and Nuclear Medicine, Sestre Milosrdnice University Hospital Center, Zagreb, Croatia
Davor Jezek ; Department of Histology, School of Medicine, University of Zagreb, Zagreb, Croatia; Department of Obstetrics and Gynaecology, Sestre Milosrdnice University Hospital Center, University of Zagreb, Zagreb, Croatia
Vlatka Tomic ; Department of Histology, School of Medicine, University of Zagreb, Zagreb, Croatia; Department of Obstetrics and Gynaecology, Sestre Milosrdnice University Hospital Center, University of Zagreb, Zagreb, Croatia
Vesna Gall ; Department of Histology, School of Medicine, University of Zagreb, Zagreb, Croatia; Department of Obstetrics and Gynaecology, Sestre Milosrdnice University Hospital Center, University of Zagreb, Zagreb, Croatia
Goran Adzic ; Department of Obstetrics and Gynaecology, Clinical Hospital Mostar, University of Mostar, Mostar, Bosnia and Herzegovina

Abstract

Hypersecretion of prolactin by lactotroph cells of the anterior pituitary may lead to hyperprolactinemia in physiological, pathological and idiopathic conditions. Most patients with idiopathic hyperprolactinemia may have radiologically undetected microprolactinomas, but some may present other causes of hyperprolactinemia described as macroprolactinemia. This condition corresponds to the predominance of higher molecular mass prolactin forms (big-big prolactin, MW > 150 kDa), that have been postulated to represent prolactin monomer complexed with anti-prolactin immunoglobulins or autoantibodies. The prevalence of macroprolactinemia in hyperprolactinemic populations between 15-46% has been reported. In the pathophysiology of macroprolactinemia it seems that pituitary pro-lactin has antigenicity, leading to the production of anti-prolactin autoantibodies, and these antibodies reduce prolactin bioactivity and delay prolactin clearance. Antibody-bound prolactin is big enough to be confined to vascular spaces, and therefore macroprolactinemia develops due to the delayed clea-rance of prolactin rather than increased production. Although the clinical symptoms are less frequent in macroprolactinemic patients, they could not be differentiated from true hyperprolactinemic patients, on the basis of clinical features alone. Although gel filtration chromatography (GFC) is known to be the gold standard for detecting macroprolactin, the polyethylene glycol precipitation (PEG) method has offered a simple, cheap, and highly suitable alternative. In conclusion, macroprolactinemia can be considered a benign condition with low incidence of clinical symptoms and therefore hormonal and imaging investigations as well as medical or surgical treatment and prolonged follow-up are not necessary.

Keywords

macroprolactin; diagnosis; clinical features; pathophysiology

Hrčak ID:

83221

URI

https://hrcak.srce.hr/83221

Publication date:

15.6.2012.

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