Persistence of Macroprolactinemia Due to Antiprolactin Autoantibody before, during, and after Pregnancy in a Woman with Systemic Lupus Erythematosus

Abstract

A woman with systemic lupus erythematosus (SLE) with marked increases in circulating 150-kDa PRL was studied from before conception, throughout pregnancy, and after pregnancy. The clinical features of the patient included idiopathic hyperprolactinemia without clinical symptoms such as amenorrhea and galactorrhea before pregnancy. No clinical lupus activity was present during follow-up. Serum PRL increase during pregnancy in this patient was considerably higher at weeks 27 and 33 than in normal pregnant women. In contrast, serum-free PRL levels were considerably lower at weeks 20, 27, and 33 than in normal pregnant women. A 150-kDa PRL (big big PRL) species persisted as the predominant circulating form of PRL throughout each measurement in this woman with SLE. In contrast, the predominant form of PRL in serum from healthy pregnant women was little PRL (or monomeric PRL). The nature of big big PRL was due to the presence of anti-PRL autoantibodies forming an IgG-23 kDa PRL complex, in accordance with the studies by affinity chromatography for IgG and Western blot analysis. The IgG-PRL complex was fully bioactive in vitro (Nb2 rat lymphoma cell assay). Injection of the serum into the rats demonstrated that the IgG-PRL complex was cleared more slowly than serum containing predominantly monomeric PRL. The data suggest that the IgG-PRL complex has biological activity; the absence of symptoms in this woman may be attributed to the fact that due to its large molecular weight, big big PRL does not easily cross the capillary walls. Delayed clearance may account for increased serum PRL levels in this SLE patient with anti-PRL autoantibodies.

Prolactin and Autoimmunity

“…Even if high serum PRL levels are associated to lupus activity, patients with anti PRL autoantibodies have less clinical and serological SLE activity than those without anti PRL autoantibodies [36]. A possible explanation is that anti PRL antibodies attenuate the biological activity of PRL interfering with PRL-receptor binding on lymphocytes [37]. Finally, it has been suggested that PRL could have a role in activation of the allergic reactions caused by Th2 cytokines as well as IL-4 or IL-13 that induce B-cells to switch towards IgE and IgG synthesis [38].…”

Impact of macroprolactin on galactorrhea and the rate of patients possibly affected by macroprolactin

“…However, we found the number of patients with a MPRL level that may possibly affect galactorrhea to be more than twelvefold the number of patients with macroprolactinemia. Some studies on the MPRL [24][25][26][27]. Although a few studies have revealed MPRL activity to be similar to monomeric prolactin in vitro [24,25], they have not it to be apparent in vivo [26,27].…”

“…Some studies on the MPRL [24][25][26][27]. Although a few studies have revealed MPRL activity to be similar to monomeric prolactin in vitro [24,25], they have not it to be apparent in vivo [26,27]. The reason for this is presumed to be due to its high molecular weight [28,29].…”

Imunofenotipagem dos linfócitos positivos para indoleamina 2,3 dioxigenase (IDO) em cultura de células de placenta bovina

“…Dessa maneira, com a presença da IDO nos linfócitos TCD4, as células ao redor entrariam em apoptose devido à falta de triptofano e aos catabólitos tóxicos gerados pela sua quebra, atenuando a reposta imunológica na região da interface materno fetal. O estrógeno, hormônio em altas concentrações durante a gestação (Østensen 1999), possui efeitos específicos sobre as células T e B, participando da proliferação e da diferenciação destas células (Leaños-Miranda et al 2001). Nos animais com gestação mais adiantada a concentração estrogênica é bastante elevada, por isso, o seu efeito nas células imunológicas, estudadas, é mais elevado nos animais com idade gestacional avançada.…”