Clinical and laboratory aspects of investigations into prolactin isoforms by PEG precipitation and ultrafiltration techniques
The objective of this work was to study prolactin (PRL) isoforms using two methods, polyethylene glycol (PEG) precipitation and ultrafiltration (UF). Sera from 41 patients with hyperprolactinemia were available for analysis. The two techniques revealed roughly similar levels of monomeric and high-molecular weight PRL variants. The somewhat lower monomeric PRL level following UF may be attributed to separation of not only macroprolactin but also of dimeric forms of the hormone during filtration. The clinical picture of the disease and brain MRI images of the patients were consistent with low-molecular weight PRL levels. Comparison of monomeric PRL levels showed no significant difference between the results of measurements by the two methods.