Clinical manifestations, evaluation and management of hyperprolactinemia in adolescent and young girls: a brief review

Neuroendocrine disturbances in women with functional hypothalamic amenorrhea: an update and future directions

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of both primary and secondary amenorrhea in women of reproductive age. It is characterized by chronic anovulation and the absence of menses that appear as a result of stressors such as eating disorders, excessive exercise, or psychological distress. FHA is presumed to be a functional disruption in the pulsatile secretion of hypothalamic gonadotropin-releasing hormone, which in turn impairs the release of gonadotropin. Hypoestrogenism is observed due to the absence of ovarian follicle recruitment. Numerous neurotransmitters have been identified which play an important role in the regulation of the hypothalamic-pituitary-ovarian axis and of which the impairment would contribute to developing FHA. In this review we summarize the most recent advances in the identification of contributing neuroendocrine disturbances and relevant contributors to the development of FHA.

Identifying a causal link between prolactin signaling pathways and COVID-19 vaccine-induced menstrual changes

COVID-19 vaccines have been instrumental tools in the fight against SARS-CoV-2 helping to reduce disease severity and mortality. At the same time, just like any other therapeutic, COVID-19 vaccines were associated with adverse events. Women have reported menstrual cycle irregularity after receiving COVID-19 vaccines, and this led to renewed fears concerning COVID-19 vaccines and their effects on fertility. Herein we devised an informatics workflow to explore the causal drivers of menstrual cycle irregularity in response to vaccination with mRNA COVID-19 vaccine BNT162b2. Our methods relied on gene expression analysis in response to vaccination, followed by network biology analysis to derive testable hypotheses regarding the causal links between BNT162b2 and menstrual cycle irregularity. Five high-confidence transcription factors were identified as causal drivers of BNT162b2-induced menstrual irregularity, namely: IRF1, STAT1, RelA (p65 NF-kB subunit), STAT2 and IRF3. Furthermore, some biomarkers of menstrual irregularity, including TNF, IL6R, IL6ST, LIF, BIRC3, FGF2, ARHGDIB, RPS3, RHOU, MIF, were identified as topological genes and predicted as causal drivers of menstrual irregularity. Our network-based mechanism reconstruction results indicated that BNT162b2 exerted biological effects similar to those resulting from prolactin signaling. However, these effects were short-lived and didn't raise concerns about long-term infertility issues. This approach can be applied to interrogate the functional links between drugs/vaccines and other side effects.

The significance of prolactin in systemic connective tissue diseases

Objectives

Does prolactin (PRL) level testing in the diagnosis of systemic connective tissue diseases make sense and should we test it in everyday practice?

Material and methods

Connective tissue diseases (CTDs) are a group of heterogeneous disorders, involving multiple body systems. Rheumatoid arthritis (RA) is one of the most common connective tissue diseases with a global prevalence of 0.3-1% and can be inherited. Less common are systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), systemic sclerosis (SSc), primary Sjögren's syndrome (pSS) and inflammatory myositis. Prolactin is responsible for lactation, breast growth and many other bodily processes, and is elevated in blood of woman who are pregnant or breastfeeding. Hyperprolactinemia is relatively common in women, so some rheumatic diseases may be caused by high prolactin levels, and it should be detected during diagnosis.

Results

Prolactin signals are found in arthritic joint tissues (chondrocytes and synovial fibroblasts) to inhibit cartilage degradation, synovitis and osteoclastogenesis. On the other hand, hyperprolactinemia also promotes the conversion of PRL to vasoinhibin, a fragment of PRL that directly stimulates and indirectly inhibits arthritis in a cell type-dependent manner. The role of the PRL/vasoinhibin axis in inflammatory arthritis should still be monitored and further research is needed to help elucidate the role of PRL in rheumatic diseases in order to ultimately develop new therapeutic interventions that can be tested in patients.

Conclusions

Nowadays, there are no clear indications for prolactin testing in the diagnosis of systemic connective tissue diseases. In the case of suspicion or confirmation of some systemic connective tissue diseases, such as rheumatoid arthritis or systemic lupus erythematosus, testing the prolactin level makes sense when severity of disease symptoms is observed.

A Meta-Analysis of Antipsychotic-Induced Hypo- and Hyperprolactinemia in Children and Adolescents

Objective: Antipsychotic-related prolactin changes may expose children and adolescents to severe adverse reactions (ARs) related to pubertal development and growth. We therefore aimed to assess the effects of antipsychotics on prolactin levels and associated somatic ARs in children and adolescents. Methods: We systematically searched PubMed and CENTRAL for placebo-controlled randomized trials of antipsychotics in children and adolescents aged ≤18 years, reporting prolactin levels and related ARs. We conducted a random-effect meta-analysis and assessed risk of bias version 2 (ROB2). Results: Thirty-two randomized controlled trials with an average trial duration of 6 weeks, covering 4643 participants with an average age of 13 years and a male majority of 65.3%. Risk of bias across domains was low or unclear. The following antipsychotic compounds: aripiprazole (n = 810), asenapine (n = 506), lurasidone (n = 314), olanzapine (n = 179), paliperidone (n = 149), quetiapine (n = 381), risperidone (n = 609), and ziprasidone (n = 16) were compared with placebo (n = 1658). Compared with placebo, statistically significant higher prolactin increase occurred with risperidone (mean difference [MD] = 28.24 ng/mL), paliperidone (20.98 ng/mL), and olanzapine (11.34 ng/mL). Aripiprazole significantly decreased prolactin (MD = -4.91 ng/mL), whereas quetiapine, lurasidone, and asenapine were not associated with significantly different prolactin levels than placebo. Our results on ziprasidone are based on a single study, making it insufficient to draw strong conclusions. On average, 20.8% of patients treated with antipsychotic developed levels of prolactin that were too high (hyperprolactinemia), whereas only 1.03% of patients reported prolactin-related ARs. Data were highly limited for long-term effects. Conclusions: In children and adolescents, risperidone, paliperidone, and olanzapine are associated with significant prolactin increase, whereas aripiprazole is associated with significant decrease. Despite the significant changes in prolactin level, few ARs were reported. Study protocol on PROSPERO: CRD42018116451.

Minimal Effects of Cariprazine on Prolactin Levels in Bipolar Disorder and Schizophrenia

BACKGROUND

Many medications used to treat schizophrenia and bipolar I disorder are linked to hyperprolactinemia. The effects of cariprazine, a dopamine D₃/D₂ receptor partial agonist, on prolactin levels in patients with schizophrenia or bipolar I disorder were evaluated.

METHODS

Effects on prolactin were evaluated using pooled data from randomized, double-blind, placebo-controlled studies in patients with schizophrenia (4 studies; 6-week duration; cariprazine 1.5-3 mg/d, 4.5-6 mg/d, and 9-12 mg/d), bipolar mania (3 studies; 3-week duration; cariprazine 3-6 and 9-12 mg/d), and bipolar depression (3 studies; 6- to 8-week duration; cariprazine 1.5 and 3 mg/d). Long-term effects were analyzed using open-label studies in patients with schizophrenia (2 studies; 48-week duration) and patients with bipolar mania (1 study; 16-week duration). Change in prolactin levels (ng/mL) from baseline to study endpoint was evaluated in subsets of sex and prior medication use.

RESULTS

In patients with schizophrenia (male, n = 1377; female, n = 558), median prolactin changes were -1.2 for males and -7.4 for females on placebo, and ranged from -4.2 to -3.6 for males and -12.4 to +0.2 for females in the cariprazine-treatment groups. In patients with bipolar mania (male, n = 570; female, n = 395), median prolactin changes were -0.2 for males and -1.1 for females on placebo and ranged from -2.1 to -3.0 for males and 0 to +1.8 for females in the cariprazine-treatment groups. Median decreases were also seen in the long-term studies of schizophrenia (range, -14.6 to -2.0) and bipolar mania (range, -0.8 to +1.9). In patients with bipolar depression (male, n = 485; female, n = 780), median prolactin changes were +0.3 for males and +0.7 for females on placebo and ranged from +0.4 to +0.5 for males and +3.0 to +3.1 for females in the cariprazine-treatment groups.

CONCLUSION

Treatment with cariprazine for schizophrenia or bipolar I disorder was associated with minimal effects on prolactin levels.