Prolactin and Autoimmunity

Abstract

The great asymmetry of autoimmune diseases between genders represents one of the most enigmatic observations among the mosaic of autoimmunity. Sex hormones are believed to play a crucial role on this dimorphism. The higher prevalence of autoimmunity among women at childbearing ages, disease onset/relapses during pregnancy, and post-partum are some of the arguments that support this hypothesis. Certainly, motherhood represents one of the most remarkable challenges for the immune system, which not only has to allow for the conceptus, but also has to deal with complex endocrine alterations. Hormonal homeostasis is known to exert a crucial influence in achieving a competent and healthy immune system. Prolactin (PRL) has a bioactive function acting as a hormone and a cytokine. It interferes with immune system modulation, mainly inhibiting the negative selection of autoreactive B lymphocytes. Likewise, hyperprolactinemia has been described in relation to the pathogenesis and activity of several autoimmune disorders. Dopamine is an effective inhibitor of PRL secretion due to either a direct influence on the hypophysis or stimulation of postsynaptic dopamine receptors in the hypothalamus, arousing the release of the PRL inhibitory factor. Hence, dopamine agonists have proven to offer clinical benefits among autoimmune patients and represent a promising therapy to be explored. In this review, we attempt to provide a critical overview of the link between PRL, autoimmune diseases, and motherhood.

No impact of treated hyperprolactinemia on cumulative live birth rate and perinatal outcomes in in vitro fertilization‐embryo transfer

“…Using the same model, Gomes et al demonstrated that the amounts of endometrial glycosaminoglycan, which taking part in decidualization, implantation and pregnancy maintenance, changed in hyperprolactinemic mice. Lastly, hyperprolactinemia may have a negative effect on implantation through immune disturbance . For example, prolactin influences macrophage activity in endometrium and changes the pattern of released immunological factors, which might disturb pregnancy …”

“…Lastly, hyperprolactinemia may have a negative effect on implantation through immune disturbance. 16,17 For example, prolactin influences macrophage activity in endometrium and changes the pattern of released immunological factors, which might disturb pregnancy. 18 Currently, there is limit data answering the question whether hyperprolactinemia, especially asymptomatic one, existing before COS, has any positive or negative effect on ART outcomes.…”

Hyperprolactinaemia

“…It has been shown that the risk and severity of RA are decreased in reproductive states characterized by hyperprolactinaemia (pregnancy and breastfeeding) [148]. However, others have demonstrated that severe disease is associated with longer period of breast-feeding and larger number of breastfed children [149]. A randomized placebo controlled study of bromocriptine offered in 88 patients with active RA on background treatment with methotrexate did not have any significant impact on disease activity score at three months [150].…”

Impact of hyperprolactinemia in a patient with polyautoimmunity

“…The role of prolactin (PRL) in the development of autoimmune diseases (ADs), such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), has been previously recognized . Consequently, hyperprolactinemia has been postulated as a triggering factor of autoimmunity and as a predictor of disease activity and severity . PRL is related to a wide variety of functions including mammary gland growth, lactation, stress response, immune system development, and autoimmunity .…”

“…Consequently, hyperprolactinemia has been postulated as a triggering factor of autoimmunity and as a predictor of disease activity and severity . PRL is related to a wide variety of functions including mammary gland growth, lactation, stress response, immune system development, and autoimmunity . In fact, it was recognized that at high PRL levels (>100 ng/mL) the immune system is inactivated; however, sometimes at slightly raised levels (20‐40 ng/mL) the immune activity increases .…”