In this issue of the journal, Rodríguez Carranza, et al. present a series of 14 women with mild hyperprolactinemia (about 80 ng/ml) who had not been treated pharmacologically or who had not responded satisfactorily to dopamine agonist treatment1. Surprisingly, eight of them (58%) proved to have a greater than 60% proportion of macroprolactin (macroPRL). Although such an unusually high prevalence of macro-PRL is likely the result of a selection bias, perhaps the most remarkable feature of this study is the finding of menstrual abnormalities and/or galactorrhea in approximately 70% of the patients. This is reminiscent of a previously published study by Hattori, et al. who followed a large group of patients with macroPRL and found that 68% had menstrual abnormalities and up to 40% had galactorrhea. Therefore, it seems that not all patients with macroPRL are asymptomatic. In trying to understand this apparent paradox, we should remember that the ratio of monomeric PRL/macro-PRL is not stable. At least two factors influence this circumstance; first, a dissociation phenomenon between PRL and IgG that can release a greater amount of biologically active monomeric PRL3 and, second, the inability of macroPRL to reach its receptors in the hypothalamus, which can result in a reduction in dopaminergic tone due to a reduction of negative feedback inhibition and, consequently, an increased production of monomeric PRL. Supporting this sequenceof events, monomeric hyperprolactinemia may develop in a substantial proportion of subjects with macroPRL upon long-term follow up.
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2017-07-24 | 437 visitas | Evalua este artículo 0 valoraciones
Vol. 4 Núm.2. Abril-Junio 2017 Pags. 57 Rev Mex Endocrinol Metabol Nut 2017; 4(2)