Macroprolactin: From laboratory to clinical practice

• Published in: Endocrinología, diabetes y nutrición. diabetes y nutrición., 2022-01, Vol.69 (1), p.63-69
• Main Authors: Biagetti, Betina, Ferrer Costa, Roser, Alfayate Guerra, Rocío, Álvarez García, Elías, Berlanga Escalera, Eugenio, Casals, Gregori, Esteban Salán, Margarita, Granada Ibern, María-Luisa, Gorrín Ramos, Jorge, López Lazareno, Nieves, Oriola, Josep, Sánchez Martínez, Pilar María, Torregrosa Quesada, M. Eugenia, Urgell Rull, Eulàlia, García Lacalle, Concepción
• Format: Article
• Language: English
• Subjects: Big prolactin; Gran prolactina; Humans; Hyperprolactinemia - diagnosis; Hyperprolactinemia - etiology; Laboratories; Macroprolactin; Macroprolactina; Pituitary Neoplasms - complications; Pituitary Neoplasms - diagnosis; Polietilenglicol; Polyethylene glycol; Prolactin; Prolactina
• ISSN: 2530-0180; 2530-0180
• DOI: 10.1016/j.endien.2022.01.001

Prolactin measurement is very common in standard clinical practice. It is indicated not only in the study of pituitary adenomas, but also when there are problems with fertility, decreased libido, or menstrual disorders, among other problems. Inadequate interpretation of prolactin levels without contextualizing the laboratory results with the clinical, pharmacological, and gynecological/urological history of patients leads to erroneous diagnoses and, thus, to poorly based studies and treatments. Macroprolactinemia, defined as hyperprolactinemia due to excess macroprolactin (an isoform of a greater molecular weight than prolactin but with less biological activity), is one of the main causes of such erroneous diagnoses, resulting in poor patient management when not recognized. There is no unanimous agreement as to when macroprolactin screening is required in patients with hyperprolactinemia. At some institutions, macroprolactin testing by polyethylene glycol (PEG) precipitation is routinely performed in all patients with hyperprolactinemia, while others use a clinically based approach. There is also no consensus on how to express the results of prolactin/macroprolactin levels after PEG, which in some cases may lead to an erroneous interpretation of the results. The objectives of this study were: 1. To establish the strategy for macroprolactin screening by serum precipitation with PEG in patients with hyperprolactinemia: universal screening versus a strategy guided by the alert generated by the clinician based on the absence or presence of clinical symptoms or by the laboratory when hyperprolactinemia is detected. 2. To create a consensus document that standardizes the reporting of prolactin results after precipitation with PEG to minimize errors in the interpretation of the results, in line with international standards. La medición de la prolactina es muy frecuente en la práctica clínica habitual. Está indicada no solo en el estudio de los adenomas hipofisarios, sino también cuando hay problemas de fertilidad, disminución de la libido o trastornos menstruales, entre otros. Una interpretación incorrecta de la concentración de la prolactina sin contextualizar los resultados analíticos con la historia clínica, farmacológica y gineco/urológica de los pacientes lleva a diagnósticos erróneos y, por lo tanto, a estudios y tratamientos mal fundamentados. La macroprolactinemia, definida como la hiperprolactinemia debida al exceso de macroprolactina (isoforma de mayor