Prolactin presents important size heterogeneity in terms of circulating molecular forms. Besides the monomer (23kDa), which predominates in healthy subjects as well as in patients with prolactinoma, high molecular forms are also present in low concentrations (1). These high molecular forms include 50 kDa dimers (big prolactin) and also forms with even larger molecular weights (MW>150 kDa), know...

Macroprolactin, a prolactin-immunoglobulin complex, continues to be problem for prolactin measurement. It is detected by all immunoassays leading falsely elevated levels. The current recommended best practice screen samples with high level using PEG precipitation estimate the biologically active level. While many labs test macroprolactin results from number of surveys indicate that there variab...

Macroprolactinemia is characterized by a large molecular mass of PRL (macroprolactin) as the main molecular form of PRL in sera, the frequent elevation of serum PRL (hyperprolactinemia), and the lack of symptoms. Macroprolactin is largely a complex of PRL with immunoglobulin G (IgG), especially anti-PRL autoantibodies. The prevalence of macroprolactinemia is 10-25% in patients with hyperprolact...

Macroprolactin may cause elevation of prolactin (PRL) concentrations measured by standard assays. In our study, we assessed the prevalence of pituitary lesions in women with macroprolactinaemia and either oligomenorrhoea or secondary amenorrhoea. Pituitary MRI scans were performed in 61 women aged 31.0  ±  6.7 years (mean  ±  SD), with raised PRL concentrations due to macroprolactinaemia, detec...

BACKGROUND Increased serum concentrations of macroprolactin are a relatively common cause of misdiagnosis and mismanagement of hyperprolactinemic patients. METHODS We studied sera from a cohort of 42 patients whose biochemical hyperprolactinemia was explained entirely by macroprolactin. Using 5 pretreatments, polyethylene glycol (PEG), protein A (PA), protein G (PG), anti-human IgG (anti-hIgG...

Prolactin (PRL) is a 198 polypeptide hormone involved in many biological functions in women. The main role of PRL is primarily associated with lactation and breast development. There are 3 isoforms of PRL: the little (23 kDa), the big (50-60 kDa) and the big-big also named macroprolactin (> 100 kDa). Macroprolactin was described for the first time nearly 30 years ago but the structure of the co...

Background. Macroprolactin, the high-molecular prolactin isoform, is considered to be an inactive in vivo product with extrapituitary origin. Patients with macroprolactinemia are usually asymptomatic, with negative pituitary imaging. Based on these data, most authors do not recommend treatment and long-term followup in subjects with macroprolactinemia. However, there is evidence for overlapping...