Prolactin and autoimmunity

Prolactin, autoimmunity, and motherhood: when should women avoid breastfeeding?

The sexual dimorphic prevalence of autoimmunity represents one of the most alluring observations among the mosaic of autoimmunity. Sex hormones are believed to be a mainstay of this asymmetry. The greater prevalence of autoimmunity among fertile women, disease onset/relapses during pregnancy, and postpartum are some of the points that support this theory. Undeniably, motherhood represents one of the most remarkable challenges for the immune system that not only has to allow for the conceptus but also deal with extraordinary hormonal alterations. Prolactin has a recognized immune-stimulatory effect, mainly inhibiting the negative selection of autoreactive B lymphocytes. In accordance, hyperprolactinemia has been associated with several autoimmune diseases, interfering with its pathogenesis and activity. During the pregnancy and lactation period, assorted autoimmune patients experience relapses, suggesting an active interference from increased levels of prolactin. This association was found to be significant in systemic lupus erythematosus, rheumatoid arthritis, and peripartum cardiomyopathy. Furthermore, treatment with bromocriptine has shown beneficial effects specially among systemic lupus erythematosus patients. In this review, we attempt to provide a critical overview of the link between prolactin, autoimmune diseases, and motherhood, emphasizing whether breastfeeding should be avoided among women, both with diagnosed disease or high risk for its development.

Impact of hyperprolactinemia in a patient with polyautoimmunity

Hyperprolactinemia has been proposed as a triggering factor for autoimmune diseases. The increased levels of prolactin could induce an abnormal immune response. Herein, we present a patient with hyperprolactinemia who developed polyautoimmunity. Patient's symptoms were associated with slightly raised levels of prolactin (20-40 ng/mL) and administration of dopaminergic agonists.

Circulating levels of prolactin are elevated in patients with rheumatoid arthritis: a meta-analysis

BACKGROUND

Prolactin (PRL), an inflammatory hormone with cytokine properties, has long been proposed to play a crucial role in the pathogenesis of autoimmune disorders, including rheumatoid arthritis (RA). However, the circulating levels of PRL in RA were discordant among published studies.

METHODS

PubMed, Embase, and The Cochrane Library database were systematically searched from inception up to 30 June 2018. The available studies were obtained from the initial search in accordance with the rigorous inclusion and exclusion criteria. Relevant data from the included literatures were extracted. Methodological quality was evaluated in order to refine the final search results. All statistical analyses were conducted using software STATA version 12.0.

RESULTS

Of 698 articles were yielded for eligibility, a finally analysis involving 628 RA cases and 430 controls from 14 published studies were included. When compared to healthy controls, there was a significantly higher level of circulating PRL in patients with RA with a pooled SMD of 1.08 (95% CI = 0.41 to 1.74, P< 0.001), particularly in Asians, age ≥50, enzyme-linked immunosorbent assay (ELISA) group and subjects with erythrocyte sedimentation rate (ESR) ≥25 mm/h.

CONCLUSIONS

Our meta-analysis demonstrates a significantly higher level of circulating PRL in RA patients when compared to healthy controls, and it was associated with region, age, measurement type and ESR.

Stress-Induced Hyperprolactinemia: Pathophysiology and Clinical Approach

While prolactin is most well known for its role in lactation and suppression of reproduction, its physiological functions are quite diverse. There are many etiologies of hyperprolactinemia, including physiologic as well as pathologic causes. Physiologic causes include pregnancy, lactation, sleep-associated, nipple stimulation and sexual orgasm, chest wall stimulation, or trauma. Stress is also an important physiologic cause of hyperprolactinemia, and its clinical significance is still being explored. This review will provide an overview of prolactin physiology, the role of stress in prolactin secretion, as well as the general clinical approach to hyperprolactinemia.

MECHANISMS IN ENDOCRINOLOGY: Hypophysitis: diagnosis and treatment

Hypophysitis is a rare condition characterised by inflammation of the pituitary gland, usually resulting in hypopituitarism and pituitary enlargement. Pituitary inflammation can occur as a primary hypophysitis (most commonly lymphocytic, granulomatous or xanthomatous disease) or as secondary hypophysitis (as a result of systemic diseases, immunotherapy or alternative sella-based pathologies). Hypophysitis can be classified using anatomical, histopathological and aetiological criteria. Non-invasive diagnosis of hypophysitis remains elusive, and the use of currently available serum anti-pituitary antibodies are limited by low sensitivity and specificity. Newer serum markers such as anti-rabphilin 3A are yet to show consistent diagnostic value and are not yet commercially available. Traditionally considered a very rare condition, the recent recognition of IgG4-related disease and hypophysitis as a consequence of use of immune modulatory therapy has resulted in increased understanding of the pathophysiology of hypophysitis. Modern imaging techniques, histological classification and immune profiling are improving the accuracy of the diagnosis of the patient with hypophysitis. The objective of this review is to bring readers up-to-date with current understanding of conditions presenting as hypophysitis, focussing on recent advances and areas for future development. We describe the presenting features, investigation and diagnostic approach of the patient with likely hypophysitis, including existing conventional techniques and those in the research/development arena. Hypophysitis usually results in acute and persistent pituitary hormone deficiency requiring long-term replacement. Management of hypophysitis includes control of the inflammatory pituitary mass using a variety of treatment strategies including surgery and medical therapy. Glucocorticoids remain the mainstay of medical treatment but other immunosuppressive agents (e.g. azathioprine, rituximab) show benefit in some cases, but there is a need for controlled studies to inform practice.

Prolactin Variants in Human Pituitaries and Pituitary Adenomas Identified With Two-Dimensional Gel Electrophoresis and Mass Spectrometry

Human prolactin (hPRL) plays multiple roles in growth, metabolism, development, reproduction, and immunoregulation, which is an important protein synthesized in a pituitary. Two-dimensional gel electrophoresis (2DE) is an effective method in identity of protein variants for in-depth insight into functions of that protein. 2DE, 2DE-based PRL-immunoblot, mass spectrometry, and bioinformatics were used to analyze hPRL variants in human normal (control; n = 8) pituitaries and in five subtypes of pituitary adenomas [NF- (n = 3)-, FSH+ (n = 3)-, LH+ (n = 3)-, FSH+/LH+ (n = 3)-, and PRL+ (n = 3)-adenomas]. Six hPRL variants were identified with different isoelectric point (pI)-relative molecular mass (Mr ) distribution on a 2DE pattern, including variants V1 (pI 6.1; 26.0 kDa), V2 (pI 6.3; 26.4 kDa), V3 (pI 6.3; 27.9 kDa), V4 (pI 6.5; 26.1 kDa), V5 (pI 6.8; 25.9 kDa), and V6 (pI 6.7; 25.9 kDa). Compared to controls, except for variants V2-V6 in PRL-adenomas, V2 in FSH+-adenomas, and V3 in NF--adenomas, the other PRL variants were significantly downregulated in each subtype of pituitary adenomas. Moreover, the pattern of those six PRL variants was significantly different among five subtypes of pituitary adenomas relative to control pituitaries. Different hPRL variants might be involved in different types of PRL receptor-signaling pathways in a given condition. Those findings clearly revealed the existence of six hPRL variants in human pituitaries, and the pattern changes of six hPRL variants among different subtypes of pituitary adenomas, which provide novel clues to further study the functions, and mechanisms of action, of hPRL in human pituitary and in PRL-related diseases, and the potential clinical value in pituitary adenomas.

Do Prolactin and its Receptor Play a Role in Alopecia Areata?

Context:

Studying the link between prolactin and autoimmunity has gained much ground over the past years. Its role played in alopecia areata (AA) is not clear yet, as previous reports yielded controversial results.

Aims:

This study aimed to measure the serum level of prolactin and to detect the expression of its receptor in AA, in an attempt to highlight its possible role in the pathogenesis of this disease.

Subjects and Methods:

A case-control study of 30 AA patients and 20 controls from outpatient clinic were undertaken. Every patient was subjected to history taking and clinical examination to determine the severity of alopecia tool (SALT) score. Blood samples were taken from patients and controls to determine the serum prolactin level. Scalp biopsies were obtained from the lesional skin of patients and normal skin of controls for assessment of the prolactin receptor.

Statistical Analysis:

Depending upon the type of data, t-test, analysis of variance test, Chi-square, receiver operator characteristic curve were undertaken.

Results:

On comparing the serum prolactin level between patients and controls, no significant difference was found, while the mean tissue level of prolactin receptor was significantly higher in patients than in controls. In patients, a significant positive correlation was found between the prolactin receptor and the SALT score.

Conclusions:

Prolactin plays a role in AA, and this role is probably through the prolactin receptors rather than the serum prolactin level.

Monoclonal Antibody Against Prolactin Receptor: A Randomized Placebo-Controlled Study Evaluating Safety, Tolerability, and Pharmacokinetics of Repeated Subcutaneous Administrations in Postmenopausal Women

BAY 1158061 is a potent monoclonal prolactin (PRL) receptor antibody, blocking PRL receptor (PRLR)-mediated signaling in a noncompetitive manner, which was tested in a randomized, placebo-controlled multiple dose study in postmenopausal women. The objective was to investigate safety, tolerability, pharmacokinetic characteristics, and effects of BAY 1158061 on serum PRL level. The study consisted of 4 parallel groups receiving up to 3 subcutaneous (sc) administrations of BAY 1158061 or placebo in 2 different dosing regimens. Twenty-nine healthy postmenopausal women were randomized and treated with BAY 1158061 or placebo: 30 mg at 14-day interval (7 participants), 60 mg at 28-day interval (8 participants), 90 mg at 14-day interval (7 participants), and placebo (7 participants). To keep the blinding, all randomized participants received sc injections biweekly (14-day interval) on 3 occasions in the lower abdomen. The PRLR antibody showed a favorable safety and tolerability profile in postmenopausal women with no distinct differences in occurrence of adverse events in BAY 1158061 or placebo-treated participants. BAY 1158061 displayed low immunogenicity with low titers of antidrug antibodies and absence of neutralizing antidrug antibodies. Pharmacokinetics were characterized by slow absorption after sc administration with median peak plasma concentrations 7 to 11 days after first dose and about 2-fold accumulation after repeated dosing every 2 weeks. The apparent mean elimination half-life was 9 to 16 days. The PRL concentration-time profiles over 24 hours showed no differences between verum- and placebo-treated participants. Based on the data obtained, BAY 1158061 is considered a good candidate for further development in endometriosis or other PRL-mediated disease conditions.

ROSACEA IS ASSOCIATED WITH THYROID AUTOIMMUNITY: A CASE CONTROL STUDY

BACKGROUND AND AIMS

There are numerous intrinsic and extrinsic factors associated with the pathophysiology of rosacea, including immune dysregulation. The aim of this study is to determine the relationship between rosacea and thyroid autoimmunity.

METHODS

Seventy-two patients with rosacea and 62 rosacea-free control subjects were included in the study. Serum free triiodothyronine (fT3), free thyroxine (fT4), thyrotropin releasing hormone (TSH), antithyroidperoxidase antibody (ATPO), antithyroglobulin (anti-Tg), prolactin, dehydroepiandrosterone sulfate (DHEAS), basal cortisol, serum CRP concentrations and erythrocyte sedimentation rate were measured.

RESULTS

The number of the cases with high levels of CRP, anti-M and prolactin in rosacea group were significantly higher than the controls (p<0.05), there was no significant difference according to other parameters in both groups (p>0.05). There was no significant difference according to the presence of a thyroid disease in both groups (p>0.05). The decrease in the CRP parameter in patients with the disease duration of 1-5 years was found to be statistically significant (βCRP=-0.251, pCRP<0.05). There was no statistically significant difference according to disease severity or disease duration (p>0.05).

CONCLUSIONS

Rosacea may be associated with high thyroid autoantibodies, prolactin and CRP levels, in which immune-endocrine interactions are important.

Clinical characteristics, classification and surgical treatment of periductal mastitis

Background

This study aimed to describe the clinical characteristics of periductal mastitis (PDM), propose the practical clinical classification system and evaluate the results of different surgical treatments in different type of PDM patients.

Methods

A retrospective study was carried out at department of breast surgery, Peking Union Medical College Hospital, Beijing, China. A total of 152 patients with the diagnosis of PDM were reviewed from March 2012 to December 2016. All of the patients underwent surgery. Data were collected regarding clinical manifestation, treatment, and outcomes.

Results

The median age was 36 years. A subareolar breast mass was the most frequent symptom. The most common clinical manifestations were mass (98.0%), rubefaction (41.1%), nipple retraction (36.8%), abscess (36.8%), skin ulceration (25.7%), and mammary duct fistula (19.1%). Fourteen (9.2%) patients were recurrent PDM at first hospitalization. Eight (5.3%) patients had prolactinoma. Five (3.3%) patients were taking antipsychotic medications. Only four (2.6%) patients were smokers. Eight patients were highly suspected to be breast cancer before surgery. A four-type classification system was first proposed according to clinical manifestations. The different surgeries in each category were evaluated. After 3 years median follow-up, 11 (7.2%) patients got recurrence including two initial recurrent PDM.

Conclusions

Periductal mastitis is a distinct benign breast condition of unknown etiology. Mass, abscess and fistula are most common manifestations of the disease. Wide surgical excision, fistulectomy and extended excision with transfer of a random breast dermo-glandular flap (BDGF) are effective surgical modalities for different type of PDM.

Roles of serum uric acid, prolactin levels, and psychosocial factors in oral lichen planus

Free radicals play important roles in the mechanisms underlying lichen planus (LP). Uric acid (UA) is an important anti-oxidant in plasma. Prolactin (PRL) is an immunomodulatory hormone that may promote LP, as has been documented in other autoimmune disorders, such as systemic lupus erythematosus, rheumatoid arthritis, and psoriasis. PRL has multiple immune-stimulatory effects and promotes the development of such autoimmune disorders. Prolactin and uric acid may serve as biomarkers of disease activity in lichen planus. The aim of the present study was to evaluate the roles of depression, stress, and anxiety in LP, as well as serum levels of UA and PRL as potential biomarkers of disease activity and compare these findings with those of the control group. Thirty-nine patients clinically diagnosed with oral LP (study group) and 39 age- and sex-matched controls (control group) were selected in this study. Serum UA and PRL levels were measured. The Depression Anxiety Stress Scale-21 was used for psychometric evaluation of LP patients and controls. Serum UA level was found to be significantly higher in the control group as well as during the remission phase of disease in the study. There was no significant difference in serum PRL levels between cases and controls. Depression and stress scores were higher in the study group.

Prolactin and Autoimmunity

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.

Prolactin-Producing Pituitary Carcinoma, Hypopituitarism, and Graves' Disease-Report of a Challenging Case and Literature Review

INTRODUCTION

The diagnosis of pituitary carcinoma is very rare, requires the evidence of metastatic disease, and has a poor overall survival. Malignant prolactinoma frequently requires dopamine agonist therapy, pituitary surgery, radiotherapy, and even chemotherapy.

CASE DESCRIPTION

A 19-year-old female presented with galactorrhea, primary amenorrhea, and left hemianopsia. Complementary study detected hyperprolactinemia and a pituitary macroadenoma with cavernous sinus invasion and suprasellar growth. She was treated with cabergoline and bromocriptine without clinical or analytical improvement. Resection of the pituitary lesion was programmed and a non-contiguous lesion of the nasal mucosa was detected during the approach. This metastasis led to the diagnosis of prolactin-producing pituitary carcinoma. After partial resection, the patient was submitted to radiotherapy for residual disease with persistent symptoms. She developed growth hormone deficiency, central hypothyroidism, hypogonadism, and permanent diabetes insipidus. Six years later she was admitted for the suspicion of secondary adrenal insufficiency and thyrotoxicosis. Physical findings, laboratory data, thyroid ultrasound, and scintigraphy achieved the diagnosis of Graves' disease and hypocortisolism. She was treated with hydrocortisone and methimazole, but central hypothyroidism recurred after antithyroid drug withdrawal. Nine years after the diagnosis of a pituitary carcinoma, she maintains treatment with bromocriptine, has a locally stable disease, with no metastases.

CONCLUSION

This report highlights an unusual presentation of a prolactin-producing pituitary carcinoma in a young female. The patient had multiple hormone deficiencies due to a pituitary lesion and treatments. The posterior development of hyperthyroidism and adrenal insufficiency brought an additional difficulty to the approach.

Prolactinomas Resistant to Treatment With Dopamine Agonists: Long-Term Follow-Up of Six Cases

Introduction: Prolactinomas are preferentially treated with dopamine agonists. However, a few adenomas are resistant to this treatment. Objective: To evaluate the characteristics of patients with resistance to dopamine agonists in the long-term. Method: A retrospective study of six cases was made. Patients who did not achieve normalized prolactin blood concentrations and a reduction of more than 50% of the tumor volume with the minimum dose of 3.5 mg per week of cabergoline for 3 months or the maximum supported dose of bromocriptine for 6 months were considered resistant to dopamine agonists. Patients were followed up at the Clinic of Neurology and Endocrinology or the University Hospital of Brasilia. Results: Six patients were selected. Three patients were initially treated with bromocriptine prior to treatment with cabergoline. Four patients were men, and two were women. At the time of diagnosis, ages ranged from 9 to 62 years. Initial prolactin concentrations ranged from 430 to 14,992 ng/mL and in the last assessment ranged from 29.6 to 2,169 ng/mL. The tumor volume ranged from 0.77 to 24.0 mm³. Tumor regression occurred in all patients, ranging from 20 to 100%, but total disappearance of the adenoma with an empty sella occurred in one patient. The maximum weekly doses of cabergoline ranged from 3.0 to 4.5 mg. Follow-up time ranged from seven to 17 years. Normalization of prolactin concentrations occurred only in one woman after 17 years of treatment. Three patients also underwent surgery, but only one woman was cured of the disease. Conclusion: This study confirms that tumors resistant to dopamine agonists are more aggressive, since we did not have any microadenoma; treatment with high dose of cabergoline may reduce the size of the tumor without its disappearance, and that normalization of prolactin concentration rarely occurs. To our knowledge, this is the longest follow-up of a series of cases with resistance to dopamine agonists.

Parity History Determines a Systemic Inflammatory Response to Spread of Ovarian Cancer in Naturally Aged Mice

Aging intersects with reproductive senescence in women by promoting a systemic low-grade chronic inflammation that predisposes women to several diseases including ovarian cancer (OC). OC risk at menopause is significantly modified by parity records during prior fertile life. To date, the combined effects of age and parity on the systemic inflammation markers that are particularly relevant to OC initiation and progression at menopause remain largely unknown. Herein, we profiled a panel of circulating cytokines in multiparous versus virgin C57BL/6 female mice at peri-estropausal age and investigated how cytokine levels were modulated by intraperitoneal tumor induction in a syngeneic immunocompetent OC mouse model. Serum FSH, LH and TSH levels increased with age in both groups while prolactin (PRL) was lower in multiparous respect to virgin mice, a finding previously observed in parous women. Serum CCL2, IL-10, IL-5, IL-4, TNF-α, IL1-β and IL-12p70 levels increased with age irrespective of parity status, but were specifically reduced following OC tumor induction only in multiparous mice. Animals developed hemorrhagic ascites and tumor implants in the omental fat band and other intraperitoneal organs by 12 weeks after induction, with multiparous mice showing a significantly extended survival. We conclude that previous parity history counteracts aging-associated systemic inflammation possibly by reducing the immunosuppression that typically allows tumor spread. Results suggest a partial impairment of the M2 shift in tumor-associated macrophages as well as decreased stimulation of regulatory B-cells in aged mice. This long term, tumor-concurrent effect of parity on inflammation markers at menopause would be a contributing factor leading to decreased OC risk.

Replication of Associations of Genetic Loci Outside the HLA Region With Susceptibility to Anti-Cyclic Citrullinated Peptide-Negative Rheumatoid Arthritis

Objective

Genetic polymorphisms within the HLA region explain only a modest proportion of anti–cyclic citrullinated peptide (anti‐CCP)–negative rheumatoid arthritis (RA) heritability. However, few non‐HLA markers have been identified so far. This study was undertaken to replicate the associations of anti‐CCP–negative RA with non‐HLA genetic polymorphisms demonstrated in a previous study.

Methods

The Rheumatoid Arthritis Consortium International densely genotyped 186 autoimmune‐related regions in3,339 anti‐CCP–negative RA patients and 15,870 controls across 6 different populations using the Illumina ImmunoChip array. We performed a case–control replication study of the anti‐CCP–negative markers with the strongest associations in that discovery study, in an independent cohort of anti‐CCP–negative UK RA patients. Individuals from the arcOGENConsortium and Wellcome Trust Case Control Consortium were used as controls. Genotyping in cases was performed using Sequenom MassArray technology. Genome‐wide data from controls were imputed using the 1000 Genomes Phase I integrated variant call set release version 3 as a reference panel.

Results

After genotyping and imputation quality control procedures, data were available for 15 non‐HLA single‐nucleotide polymorphisms in 1,024 cases and 6,348 controls. We confirmed the known markers ANKRD55 (meta‐analysis odds ratio [OR] 0.80; P = 2.8 × 10⁻¹³)and BLK (OR 1.13; P = 7.0 × 10⁻⁶) and identified new and specific markers of anti‐CCP–negative RA (prolactin [PRL] [OR 1.13; P = 2.1 × 10⁻⁶] and NFIA [OR 0.85; P = 2.5 × 10⁻⁶]). Neither of these loci is associated with other common, complex autoimmune diseases.

Conclusion

Anti‐CCP–negative RA and anti‐CCP–positive RA are genetically different disease subsets that only partially share susceptibility factors. Genetic polymorphisms located near the PRL and NFIA genes represent examples of genetic susceptibility factors specific for anti‐CCP–negative RA.

Insight into the Endocrine System and the Immune System: A Review of the Inflammatory Role of Prolactin in Rheumatoid Arthritis and Psoriatic Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects females three times more frequently than males. A potential role for hormones, such as prolactin (PRL), may in part explain this phenomenon. The risk of developing RA is increased in women who are lactating after the first pregnancy, which might be related to breastfeeding and the release of PRL. Other studies found a protective effect of PRL on RA development. Some studies have reported that hyperprolactinemia is more common in RA and serum PRL levels are correlated with several disease parameters, although others could not confirm these findings. Overall the plasma PRL levels are on average not elevated in RA. Previously, a small number of open-label clinical trials using bromocriptine, which indirectly decreases PRL levels, were performed in RA patients and showed clinical benefit, although others found the opposite effect. Locally produced PRL at the site of inflammation may have a crucial role in RA as well, as it has been shown that PRL can be produced by synovial macrophages. Locally produced PRL has both pro-inflammatory and anti-inflammatory effects in arthritis. Psoriatic arthritis (PsA) is also an autoinflammatory disease, in which the prolactin receptor is also expressed in macrophages. The aim of this review is to provide an overview of the potential role of PRL signaling in inflammatory joint diseases (RA and PsA) and its potential as a therapeutic target.

Rheumatoid arthritis and psoriatic arthritis synovial fluids stimulate prolactin production by macrophages

Prolactin (PRL) is a neuroendocrine hormone that can promote inflammation. We examined the synovial tissue and fluid levels of PRL in patients with inflammatory arthritis, PRL expression in differentiated Mϕs from patients with arthritis and from healthy donors, and the effects of different stimuli on PRL production by Mϕs. PRL levels were measured in paired synovial fluid (SF) and peripheral blood of patients with rheumatoid arthritis (RA, n = 19), psoriatic arthritis (PsA, n = 11), and gout (n = 11). Synovial-tissue PRL mRNA expression was measured by quantitative PCR in patients with RA (n = 25), PsA (n = 11), and gout (n = 12) and in Mϕs differentiated in SF of patients with RA, PsA, other subtypes of spondyloarthritis (SpA), and gout. Synovial-tissue PRL mRNA expression correlated significantly with clinical disease parameters in patients with RA and PsA, including erythrocyte sedimentation rate (ESR, r = 0.424; P = 0.049) and disease activity score evaluated in 28 joints (DAS28, r = 0.729; P = 0.017). Synovial-tissue PRL expression was similar in RA, PsA, and gout. PRL mRNA expression was detected in monocyte-derived Mϕs from patients with RA and was significantly higher (P ≤ 0.01) in Mϕs differentiated in pooled SF from patients with RA and PsA compared with SpA or gout. PRL production by Mϕ differentiation in the SF from patients with RA was not further regulated by stimulation with CD40L, IgG, LPS, or TNF. PRL is produced locally in the synovium of patients with inflammatory arthritis. The production of PRL by Mϕs was increased by unknown components of RA and PsA SF, where it could contribute to disease progression.

New insights into the immunopathogenesis of systemic lupus erythematosus

The aetiology of systemic lupus erythematosus (SLE) is multifactorial, and includes contributions from the environment, stochastic factors, and genetic susceptibility. Great gains have been made in understanding SLE through the use of genetic variant identification, mouse models, gene expression studies, and epigenetic analyses. Collectively, these studies support the concept that defective clearance of immune complexes and biological waste (such as apoptotic cells), neutrophil extracellular traps, nucleic acid sensing, lymphocyte signalling, and interferon production pathways are all central to loss of tolerance and tissue damage. Increased understanding of the pathogenesis of SLE is driving a renewed interest in targeted therapy, and researchers are now on the verge of developing targeted immunotherapy directed at treating either specific organ system involvement or specific subsets of patients with SLE. Accordingly, this Review places these insights within the context of our current understanding of the pathogenesis of SLE and highlights pathways that are ripe for therapeutic targeting.

Prolactin: Friend or Foe in Central Nervous System Autoimmune Inflammation?

The higher prevalence of multiple sclerosis (MS) in females, along with the modulation of disease activity observed during pregnancy and the post-partum period, has suggested a hormonal influence in MS. Even if prolactin (PRL) does not belong to the sex hormones family, its crucial role in female reproduction and lactation has prompted great efforts to understand if PRL could represent a gender factor in the pathogenesis of MS and experimental autoimmune encephalomyelitis (EAE), the animal model for this disease. Extensive literature has documented a remarkable immune-stimulating potential for this hormone, indicating PRL as a disease-promoting factor in MS and EAE. However, recent work has pointed out that PRL is endowed with important neuroprotective and remyelinating properties and has encouraged a reinterpretation of the involvement of this hormone in MS. In this review we summarize both the protective functions that PRL exerts in central nervous system tissue as well as the inflammatory activity of this hormone in the context of autoimmune responses against myelin. Last, we draw future lines of research that might help to better clarify the impact of PRL on MS pathology.

Revisitation of autoimmune hypophysitis: knowledge and uncertainties on pathophysiological and clinical aspects

PURPOSE

This publication reviews the accepted knowledges and the findings still discussed on several features of autoimmune hypophysitis, including the most recently described forms, such as IgG4 and cancer immunotherapy- related hypophysitis.

METHODS

The most characteristic findings and the pending controversies were derived from a literature review and previous personal experiences. A single paragraph focused on some atypical examples of the disease presenting under confounding pretences.

RESULTS

Headache, visual field alterations and impaired pituitary secretion are the most frequent clinical findings of the disease. Pituitary biopsy, still considered the gold diagnostic standard, does not always receive consent from the patients. The role of magnetic resonance imaging is limited, as this disease may generate images similar to those of other diseases. The role of antipituitary and antihypothalamus antibodies is still discussed owing to methodological difficulties and also because the findings on the true pituitary antigen(s) are still debated. However, the low sensitivity and specificity of immunofluorescence, one of the more widely employed methods to detect these antibodies, may be improved, considering a predetermined cut-off titre and a particular kind of immunostaining.

CONCLUSION

Autoimmune hypophysitis is a multifaceted disease, which may certainly be diagnosed by pituitary biopsy. However, the possible different clinical, laboratory and imaging features must be considered by the physician to avoid a misdiagnosis when examining a possibly affected patient. Therapeutic choice has to be made taking into account the clinical conditions and the degree of hypothalamic-pituitary involvement, but also considering that spontaneous remissions can occur.

Prolactin levels are associated with a pro-inflammatory body mass distribution among women with systemic lupus erythematosus

Objectives The objective of this study was to determine whether prolactin levels are associated with a pro-inflammatory body mass distribution in women with systemic lupus erythematosus (SLE). Methods This cross-sectional study was conducted in consecutive female SLE patients seen in our rheumatology department from January 2012 to July 2015. Prolactin was measured in ng/ml. Body mass distribution was measured by dual energy x-ray absorptiometry and it was divided into subtotal (whole body excluding the head), subtotal bone mineral content, lean mass index (appendicular lean mass/height²), subtotal trunk and leg fat percentages and trunk-to-leg fat ratio. The association between prolactin levels and body mass distribution components was evaluated by univariable and multivariable linear regression models adjusting for possible confounders. Results One hundred and eighty-five patients were evaluated; their mean (SD) age at diagnosis was 34.8 (13.8) years; nearly all patients were Mestizo. Patients included in this study were comparable to the rest of the cohort in terms of age, disease duration, SLEDAI, SDI and body mass index. Disease duration was 7.3 (6.6) years. The SLEDAI was 5.2 (4.3) and the SDI 0.9 (1.3). Prolactin levels were 18.9 (16.7) ng/ml. In univariable analyses, prolactin was negatively associated with bone mineral density, bone mineral content, leg fat percentage and lean mass index, and positively associated with trunk-to-leg fat ratio. In the multivariable analyses, prolactin was negatively associated with bone mineral content and positively associated with trunk-to-leg fat ratio. Conclusions Higher prolactin levels are associated with a pro-inflammatory body mass distribution in SLE patients.

Increased plasma/serum levels of prolactin in systemic lupus erythematosus: a systematic review and meta-analysis

BACKGROUND

Prolactin (PRL), a polypeptide hormone produced by the pituitary gland, is involved in the regulation of humoral and cell mediated immune responses. PRL levels have been investigated in several autoimmune diseases including systemic lupus erythematosus (SLE), however, yielded different and inconsistent results. This study aims to derive a more precise evaluation on plasma/serum PRL levels in SLE patients, as well as the potential influential factors.

METHODS

Studies published from 1 January 1987 to 31 December 2015 in English, which comparing plasma/serum PRL levels between SLE group and control group were searched in PubMed, EMBASE and The Cochrane Library databases. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analysis. Heterogeneity test was performed by the Q statistic and quantified using I², publication bias was evaluated using a funnel plot and Egger's linear regression test.

RESULTS

Five-hundred and forty-seven articles were obtained after searching databases, and 12 studies with 429 SLE patients and 326 controls were finally included. Meta-analysis revealed that, compared with the control group, the SLE group had significantly higher plasma/serum PRL levels (P < 0.001), with the SMD of 1.26 and 95%CI (0.70，1.82). Subgroup analyses showed that SLE patients from Asia and Europe had higher plasma/serum PRL levels. However, no significant change in plasma/serum PRL levels was observed in SLE patients from America (P > 0.05).

CONCLUSIONS

Overall, our study suggests that SLE patients have higher plasma/serum PRL level, but with a regional difference.

[Hyperprolactinemia: unusual association between peripheral hypothyroidism and microprolactinoma]

We report a rare case of hyperprolactinemia revealing the association between peripheral hypothyroidism and prolactin pituitary macroadenomas. The patient was a 43-year old woman, presenting with spontaneous bilateral galactorrhea over a period of 1 year. Hyperprolactinemia was confirmed and etiologic investigation revealed peripheral hypothyroidism secondary to autoimmune thyroiditis. Therapy consisted of administration of thyroid hormone, with clinical stabilization and hormonal normalization three months later. The evolution was marked by the persistence of hyperprolactinemia and galactorrhea. The diagnosis of microprolactinoma was objectified by pituitary MRI which showed microadenoma, justifying the administration of antidopaminergic therapy Six months later, the evolution was marked by normalization of prolactin levels and disappearance of pituitary microadenoma image.

The higher incidence of autoimmune thyroid disease in prolactinomas than in somatotrophinomas

OBJECTIVE

Many studies have shown that prolactin (PRL) plays an important role in autoimmune diseases. The aim of this study was to compare the current frequency of autoimmune thyroid disease (ATD) in prolactinomas with another type of functional pituitary adenoma (FPA), somatotrophinoma. Another aim of the study was to evaluate possible factors related to thyroid autoimmunity and the process of ATD in FPAs.

METHODS

We retrospectively evaluated the presence of thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) and thyroid morphologic findings in our patients with FPA (78 with acromegaly and 83 with prolactinoma). The relationship of autoantibody positivity with baseline PRL levels, activity of acromegaly, and treatment of dopamine agonists (DA) and hypogonadism was also assessed. Patients with ATD and hypothyroidism due to autoimmune thyroiditis were also evaluated.

RESULTS

ATD (Hashimoto's thyroiditis) was detected more frequently in patients with prolactinoma than in patients with acromegaly (33% and 17%, respectively; p=0.01). Thyroid autoantibody positivity was found more frequently in females in the whole group (p=0.02) and in the acromegaly group (p=0.008). There was no difference according to sex among the patients with prolactinoma (p=0.800). ATD was found not to be related with baseline PRL levels, treatment of DA, and presence of hypogonadism (p=0.232, p=0.435, p=0.464, respectively) in the prolactinoma group, and activity of acromegaly, presence of hypogonadism in the acromegaly group (p=0.753, p=0.654, respectively). Autoimmune hypothyroidism was more frequent in the prolactinoma group than in the acromegaly group among patients with thyroid autoantibody positivity (p=0.004).

CONCLUSION

Thyroid autoantibodies should be evaluated both at the time of diagnosis and during the course of treatment in patients with prolactinoma, and thyroid function tests should be closely monitored in patients with autoantibody positivity.

The role of the prolactin/vasoinhibin axis in rheumatoid arthritis: an integrative overview

Rheumatoid arthritis (RA) is a chronic, autoimmune, inflammatory disease destroying articular cartilage and bone. The female preponderance and the influence of reproductive states in RA have long linked this disease to sexually dimorphic, reproductive hormones such as prolactin (PRL). PRL has immune-enhancing properties and increases in the circulation of some patients with RA. However, PRL also suppresses the immune system, stimulates the formation and survival of joint tissues, acquires antiangiogenic properties upon its cleavage to vasoinhibins, and protects against joint destruction and inflammation in the adjuvant-induced model of RA. This review addresses risk factors for RA linked to PRL, the effects of PRL and vasoinhibins on joint tissues, blood vessels, and immune cells, and the clinical and experimental data associating PRL with RA. This information provides important insights into the pathophysiology of RA and highlights protective actions of the PRL/vasoinhibin axis that could lead to therapeutic benefits.

Evaluation of prolactin levels in patients with newly diagnosed pemphigus vulgaris and its correlation with pemphigus disease area index

BACKGROUND

Prolactin is a hormone; in addition to it known roles, it has immunomodulatory effects on lymphocytes maturation and immunoglobulins production. Hyperprolactinemia has been demonstrated in various autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, type I diabetes mellitus, and Graves' disease. In view of the prolactin immunomodulatory roles, studying prolactin levels in pemphigus as an autoimmune blistering disease may introduce new ways of understanding disease etiology and developing treatment strategies.

OBJECTIVE

Our purpose was to determine the prolactin levels in patients with newly diagnosed pemphigus vulgaris and study its correlation with pemphigus disease area index.

LIMITATION

Our study was limited by the lack of a control group.

METHODS

In this cross-sectional study, prolactin and anti-desmoglein 1 and 3 autoantibodies levels were measured in 50 patients with newly diagnosed pemphigus vulgaris in Razi Dermatology Hospital. Pemphigus severity and extent was estimated using the Pemphigus Disease Area Index.

RESULTS

Of the 50 patients, 18 were male and 32 were female with a mean age of 41.56 ± 13.66 years. Mean prolactin (PRL) level was 15.60 ± 11.72 ng/ml (10.68 in males and 18.37 in females). Mean anti-desmoglein 1 and 3 autoantibodies were 135.8 ± 119.8 and 245.8 ± 157.4 U/ml, respectively. Eleven out of 50 patients had a higher than normal prolactin range. No relation was found between prolactin level and disease activity (p = .982). Also, correlation studies show no relation between prolactin and anti-desmoglein 1 and 3 autoantibodies levels (respectively, p = .771 and .738). In comparing the extent of the disease between the two groups with normal and high prolactin, paired t-test showed no significance (p = .204).

CONCLUSION

In our study, 22% of patients had hyperprolactinemia, which was greater among females. The highest PRL level was detected in mucocutaneous group. Although serum PRL levels were higher in patients with a greater Pemphigus Disease Area Index, it did not reach statistical significance.

Prevalence of autoimmune disease in patients with prolactinomas and non-functioning pituitary adenomas

PURPOSE

Prolactin can affect autoimmune response and evidence suggests that hyperprolactinemia can primarily precipitate autoimmunity. We postulate that patients with prolactinomas are more prone to autoimmune disease (AID).

METHODS

We conducted a retrospective case-control study comparing prevalence of AID in 100 prolactinoma patients (PRL-P, cases) and 100 age- and gender-matched non-functioning pituitary adenoma patients (NFPA-P, controls) assessed at the Neuroendocrine Clinics of the McGill University Health Centre between January 2005 and December 2014. Comparisons were done using a conditional logistic regression (CLR) analysis. Multiple imputation was used to account for missing data values.

RESULTS

Sixty-eight women and 32 men were in each group. Median age was 37 years for PRL-P and 46 years for NFPA-P. AID was diagnosed in 28/100 cases and 16/100 controls. Autoimmune thyroid disease was the most common AID reported in both groups, representing 70 and 61% of the AID diagnoses respectively. CLR analysis revealed a multiplicative interaction effect between AID prevalence and age (p 0.004). Odds ratios for AID in PRL-P compared to NFPA-P increase with age and become significant at age 43, reaching 4.17 (95% CI 1.26, 13.82) at age 45 and 8.09 (95% CI 1.96, 33.43) at age 50 (p 0.05).

CONCLUSION

Our data showed a higher prevalence of AID in both PRL-P and NFPA-P than in a reference population. In both groups, prevalence of AID increased with age, given a multiplicative interaction effect. A significant higher prevalence of autoimmunity in PRL-P compared with NFPA-P occurs after age 43. These associations may have significant implications for the management of prolactinoma patients.

Spanish consensus on the risks and detection of antipsychotic drug-related hyperprolactinaemia

INTRODUCTION

Iatrogenic hyperprolactinaemia (IHPRL) has been more frequently related to some antipsychotic drugs that provoke an intense blockade of dopamine D2 receptors. There is a wide variation in clinical practice, and perhaps some more awareness between clinicians is needed. Due to the high frequency of chronic treatment in severe mental patients, careful attention is recommended on the physical risk. IHPRL symptoms could be underestimated without routine examination.

METHODOLOGY

An intense scientific literature search was performed in order to draw up a multidisciplinary consensus, including different specialists of psychiatry, endocrinology, oncology and internal medicine, and looking for a consensus about clinical risk and detection of IHPRL following evidence-based medicine criteria levels (EBM I- IV).

RESULTS

Short-term symptoms include amenorrhea, galactorrhoea, and sexual dysfunction with decrease of libido and erectile difficulties related to hypogonadism. Medium and long-term symptoms related to oestrogens are observed, including a decrease bone mass density, hypogonadism, early menopause, some types of cancer risk increase (breast and endometrial), cardiovascular risk increase, immune system disorders, lipids, and cognitive dysfunction. Prolactin level, gonadal hormones and vitamin D should be checked in all patients receiving antipsychotics at baseline although early symptoms (amenorrhea-galactorrhoea) may not be observed due to the risk of underestimating other delayed symptoms that may appear in the medium term. Routine examination of sexual dysfunction is recommended due to possible poor patient tolerance and low compliance. Special care is required in children and adolescents, as well as patients with PRL levels >50ng/ml (moderate hyperprolactinaemia). A possible prolactinoma should be investigated in patients with PRL levels >150ng/ml, with special attention to patients with breast/endometrial cancer history. Densitometry should be prescribed for males >50 years old, amenorrhea>6 months, or early menopause to avoid fracture risk.

Function of Treg Cells Decreased in Patients With Systemic Lupus Erythematosus Due To the Effect of Prolactin

Prolactin has different functions, including cytokine secretion and inhibition of the suppressor effect of regulatory T (Treg) cells in healthy individuals. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by defects in the functions of B, T, and Treg cells. Prolactin plays an important role in the physiopathology of SLE. Our objective was to establish the participation of prolactin in the regulation of the immune response mediated by Treg cells from patients with SLE. CD4CD25CD127 cells were purified using magnetic beads and the relative expression of prolactin receptor was measured. The functional activity was evaluated by proliferation assay and cytokine secretion in activated cells, in the presence and absence of prolactin. We found that both percentage and function of Treg cells decrease in SLE patients compared to healthy individuals with statistical significance. The prolactin receptor is constitutively expressed on Treg and effector T (Teff) cells in SLE patients, and this expression is higher than in healthy individuals. The expression of this receptor differs in inactive and active patients: in the former, the expression is higher in Treg cells than in Teff cells, similar to healthy individuals, whereas there is no difference in the expression between Treg and Teff cells from active patients. In Treg:Teff cell cocultures, addition of prolactin decreases the suppressor effect exerted by Treg cells and increases IFNγ secretion. Our results suggest that prolactin plays an important role in the activation of the disease in inactive patients by decreasing the suppressor function exerted by Treg cells over Teff cells, thereby favoring an inflammatory microenvironment.

Evaluation of measles-rubella vaccination for mothers in early puerperal phase

BACKGROUND

The postpartum period is an ideal opportunity to vaccinate mothers with inadequate immunity to vaccine-preventable diseases including measles and rubella.

METHODS

A prospective study of measles-rubella (MR) vaccination in the early puerperal phase was conducted in 171 mothers, who had insufficient antibody titers when screened for immunity to measles (≤ 1:4 on the neutralization test [NT]) or rubella (≤ 1:16 on the hemagglutination inhibition [HI] test) during pregnancy. To evaluate the efficacy of MR vaccination in the postpartum period, we determined their post-vaccination antibody titers and immune responses to vaccination, and investigated the association between these and their prolactin (PRL) levels and Th1/Th2 ratios at the time of vaccination. We also examined the passage of viral RNA and antigen into breast milk.

RESULTS

Of the 169 participants who completed the study schedule, 117 and 101 had low antibody titers against measles and rubella, respectively. In the measles-seronegative group, the antibody-positive rate was 87% on the NT assay, and the NT geometric mean antibody titer was 11.4 (95% confidence interval [CI], 10.0-13.0). In the rubella-seronegative group, the antibody-positive rate was 88% on the HI test assay, and the HI geometric mean antibody titer was 64.0 (95% CI, 53.9-76.0). There was no association between the post-vaccination antibody titers and the PRL levels or Th1/Th2 ratios at the time of vaccination. In the rubella-seronegative group, subjects with higher Th1/Th2 ratios showed higher rates of responsiveness than those with lower ratios (P=0.045). Although measles virus RNA was isolated from the breast milk of two vaccinated mothers, breastfeeding was not associated with clinical disease in any infants.

CONCLUSION

MR vaccination in the early puerperal phase is considered an effective way to prevent the diseases, regardless of the mother's immunological status and hormonal milieu.

Increased serum level of prolactin is related to autoantibody production in systemic lupus erythematosus

OBJECTIVE

Prolactin (PRL) is known to aid effector B cells and augment autoimmunity, but the role of PRL in systemic lupus erythematosus (SLE) is not fully elucidated. The aim of this study was to determine the correlation between the serum levels of PRL and autoantibody production in SLE.

METHODS

Blood levels of PRL, anti-double-stranded DNA (ds-DNA) antibody, immunoglobulin M (IgM) and immunoglobulin G (IgG) were determined in samples from 30 adult patients with SLE and 25 healthy controls. The relationships between the serum level of PRL and SLE disease activity, as well as the titres of the ds-DNA antibody, IgM and IgG were determined.

RESULTS

The serum level of PRL was higher in the SLE patients than in the healthy controls. PRL concentration increased during SLE flares-ups and decreased following disease remission. There was a positive correlation between the PRL concentration and serum levels of IgM, IgG and ds-DNA antibody titre.

CONCLUSION

These data suggest that the serum level of PRL was closely related to the antibody production and disease activity of SLE patients. PRL concentration was dramatically reduced upon the remission of disease activity, indicating that PRL levels might be a promising predictor of SLE disease severity.

Sex differences in Sjögren's syndrome: a comprehensive review of immune mechanisms

Autoimmune diseases (ADs) are estimated to affect between 5 and 8 % of the US population, and approximately 80 % of these patients are women. Sjögren’s syndrome (SS) is an AD that occurs predominately in women over men (16:1). The hallmark characteristic of SS is diminished secretory production from the primary exocrine gland and the lacrimal or salivary glands resulting in symptoms of dry eye and mouth. The disease is believed to be mediated by an inflammatory and autoantibody response directed against salivary and lacrimal gland tissues. This review will examine the literature on sex differences in the immune response of patients and animal models of Sjögren’s syndrome in order to gain a better understanding of disease pathogenesis.

Arsenic exposure and hepatitis E virus infection during pregnancy

BACKGROUND

Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to infection in humans.

OBJECTIVES

We aimed to assess the relation of arsenic exposure during pregnancy with immune function and hepatitis E virus (HEV) infection, defined as seroconversion during pregnancy and postpartum.

METHODS

We assessed IgG seroconversion to HEV between 1st and 3rd trimester (TM) and 3 months postpartum (PP) among 1100 pregnancies in a multiple micronutrient supplementation trial in rural Bangladesh. Forty women seroconverted to HEV and were matched with 40 non-seroconverting women (controls) by age, parity and intervention. We assessed urinary inorganic arsenic plus methylated species (∑As) (µg/L) at 1st and 3rd TM and plasma cytokines (pg/mL) at 1st and 3rd TM and 3 months PP.

RESULTS

HEV seroconverters' urinary ∑As was elevated throughout pregnancy. Non-seroconverters' urinary ∑As was similar to HEV seroconverters at 1st TM but declined at 3rd TM. The adjusted odds ratio (95% confidence interval) of HEV seroconversion was 2.17 (1.07, 4.39) per interquartile range (IQR) increase in average-pregnancy urinary ∑As. Increased urinary ∑As was associated with increased concentrations of IL-2 during the 1st and 3rd TM and 3 months PP among HEV seroconverters but not non-seroconverters.

CONCLUSIONS

The relation of urinary arsenic during pregnancy with incident HEV seroconversion and with IL-2 levels among HEV-seroconverting pregnant women suggests arsenic exposure during pregnancy may enhance susceptibility to HEV infection.

Multiple sclerosis and hyperprolactinemia: a case-control study

Multiple sclerosis (MS) is an autoimmune disease of central nervous system which is characterized with demyelination. Prolactin, synthesized in the anterior pituitary cells, has a role in maturation of immune cells, suggesting its possible implication in autoreactivity. The aim of the current study is to investigate the role of hyperprolactinemia in MS. Twenty-two MS patients with hyperprolactinemia diagnosed with pituitary adenoma and 66 MS patients without hyperprolactinemia were enrolled in our case-control study. They were matched with regard to age, gender, and MS subtypes. Patients with other concomitant autoimmune diseases and pregnancy were excluded. Statistical analyses were carried out using SPSS (SPSS statistic package, version 21.0.0) statistical software. The Pearson Chi-square test and the t test were used to determine whether there were any significant differences. The level of significance was set at p < 0.05. Greater value of relapse rate among hyperprolactinemic MS patients in comparison to non-hyperprolactinemic MS patients was statistically significant (p < 0.001). Statistically significant difference between the two groups in terms of EDSS was observed (case group vs.

CONTROL

1.3 vs. 1.9; p = 0.007). The correlation between MS duration and duration of hyperprolactinemia was significant in the case group (p < 0.05, R = 0.752). No statistically significant difference was found between two groups regarding duration of MS. This study suggested a protective role of prolactin in demyelinating procedure of MS.

Urine oligosaccharide pattern in patients with hyperprolactinaemia

Free milk-type oligosaccharides are produced during pregnancy and lactation and may have an impact on several cells in the immune system. Our aim was to investigate if patients with isolated hyperprolactinaemia, not related to pregnancy, also have increased synthesis and urinary excretion of milk-type oligosaccharides and to compare the excretion pattern with that found during pregnancy. Urine samples were collected as morning sample from 18 patients with hyperprolactinaemia, 13 healthy controls with normal prolactin levels and four pregnant women. After purification, lactose and free oligosaccharides were analysed and quantified by high-performance anion-exchange chromatography with pulsed amperometric detection. The identity of peaks was confirmed by exoglycosidase treatment and comparison with oligosaccharide standards. Prolactin was measured in serum collected between 09 and 11 a.m. by a standardized immunochemical method. Patients with hyperprolactinaemia had higher urinary excretion of lactose than normoprolactinemic controls and urinary lactose correlated positively to prolactin levels (r = 0.51, p < 0.05). Increased levels of the fucosylated oligosaccharides 2-fucosyl lactose and lacto-di-fucotetraose were found in urine from three and two patients, respectively. The acidic oligosaccharide 3-sialyl lactose was found in high amount in urine from two patients with prolactin of >10,000 mU/l. However, pregnant women in their third trimester had the highest concentration of all these oligosaccharides and excretion increased during pregnancy. This study is first to show that both lactose and certain fucosylated and sialylated milk-type oligosaccharides are increased in some patients with hyperprolactinaemia. It remains to elucidate the functional importance of these findings.

Serum macroprolactin levels in pregnancy and association with thyroid autoimmunity

BACGROUND

To assess the contribution of macroprolactin to high serum prolactin levels and their association with thyroid status and thyroid autoimmunity during pregnancy.

METHODS

138 pregnant women who suspected of having thyroid dysfunction were studied and divided into three groups according to the thyroid status; group 1; euthyroidism (n 40), group 2; hypothyroidism (n 54), and group 3; hyperthyroid (n 44). Polyethylene glycol (PEG) precipitation method was used for detection of macroprolactin. A percentage recovery of 40 % or less is considered as macroprolactinemia. If macroprolactin was negative, the percentage of monomeric prolactin recovery (monoPRL %) after PEG precipitation was used for comparison between the groups.

RESULTS

Macroprolactinemia was found in two patients (1.4 %) one from hypothyroid and other from euthyroid group. Basal prolactin levels in these patients were 400 and 403 ng/mL respectively. Referring to all patients, there was no correlation between PRL, macroPRL or monoPRL % with thyroid hormone status and also with the serum levels of thyroid antibodies (p > 0.05). A positive correlation was observed between the serum levels of PRL with TSH (p = 0.014 and r = 0.219), while a negative correlation was found with FT4 (p = 0.011 and r = -0.227).

CONCLUSIONS

Despite the fact that serum prolactin levels were found to be high during pregnancy, the contribution of macroprolactin was found to be insignificant in our study. Unlike other auto immune diseases, we could not find any relationship between thyroid autoimmunity and PRL, macroPRL or monoPRL %. These results confirmed that measured prolactin was quite homogeneous during pregnancy.

Anti-metastatic outcome of isoform-specific prolactin receptor targeting in breast cancer

Controversy exists concerning the role of the long prolactin receptor (PRLR) in the progression of breast cancer. By targeting pre-mRNA splicing, we succeeded in knocking down only the long PRLR in vivo, leaving the short forms unaffected. Using two orthotopic and highly-metastatic models of breast cancer, one of which was syngeneic (mouse 4T1) to allow assessment of tumor-immune interactions and one of which was endocrinologically humanized (human BT-474) to activate human PRLRs, we examined the effect of long PRLR knockdown on disease progression. In both models, knockdown dramatically inhibited metastatic spread to the lungs and liver and resulted in increased central death in the primary tumor. In the syngeneic model, immune infiltrates in metastatic sites were changed from innate inflammatory cells to lymphocytes, with an increase in the incidence of tumor-specific cytotoxic T cells. Long PRLR knockdown in three-dimensional culture induced apoptosis of tumor-initiating/cancer stem cells (death of 95% of cells displaying stem cell markers in 15 days). We conclude that the long PRLR plays an important role in breast cancer metastasis.

The prolactin receptor as a therapeutic target in human diseases: browsing new potential indications

INTRODUCTION

Prolactin (PRL) signaling has emerged as a relevant target in breast and prostate cancers. This has encouraged various laboratories to develop compounds targeting the PRL receptor (PRLR). As the latter is widely distributed, it is timely to address whether other conditions could also benefit from such inhibitors.

AREAS COVERED

The authors briefly overview the two classes of PRLR blockers, which involve: i) PRL-core based analogs that have been validated as competitive antagonists in various preclinical models, and ii) anti-PRLR neutralizing antibodies that are currently in clinical Phase I for advanced breast and prostate cancers. The main purpose of this review is to discuss the multiple organs/diseases that may be considered as potential targets/indications for such inhibitors. This is done in light of reports suggesting that PRLR expression/signaling is increased in disease, and/or that systemic or locally elevated PRL levels correlate with (or promote) organ pathogenesis.

EXPERT OPINION

The two immediate challenges in the field are i) to provide the scientific community with potent anti-prolactin receptor antibodies to map prolactin receptor expression in target organs, and ii) to take advantage of the availability of functionally validated PRLR blockers to establish the relevance of these potential indications in humans.

The effects of bromocriptine on preventing postpartum flare in systemic lupus erythematosus patients from South China

Objective. Prolactin plays an important role on the disease flare of postpartum SLE patients. 76 pregnant SLE patients were enrolled in this study to evaluate the efficacy of bromocriptine (an inhibitor of prolactin secretion) on preventing the postpartum disease relapse. Methods. Patients were randomly divided into the treatment group (bromocriptine, 2.5 mg oral, twice a day for 14 days after delivery) and the control group. All the patients were followed up for 12 months. Clinical features were recorded every 4 weeks. Serum prolactin and estradiol levels were measured at the second week and the second month after delivery. The endpoint of the study was disease relapse and defined when SLEDAI score increased by ≥3 points from the antenatal baseline. Results. (1) Serum levels of prolactin and estradiol decreased significantly in bromocriptine treatment group at the second week (P < 0.001) and second month (P < 0.05) after delivery compared to control group. (2) The relapse rate of the treatment group was lower than the control group (χ² = 4.68, P = 0.0305). Conclusions. Two weeks of oral bromocriptine treatment in postpartum SLE patients may relieve the disease from hyperprolactinemia and hyperestrogenemia and may be beneficial in preventing the patients from disease relapse.

Environmental estrogen bisphenol A and autoimmunity

Over the past few years, there has been evidence of the increasing prevalence of autoimmune diseases. Autoimmune diseases consist of many complex disorders of unknown etiology resulting in immune responses to self-antigens. The immune system, and its function, is under complex and integrated control and its disruption can be triggered by multiple factors. Autoimmunity development is influenced by multiple factors and is thought to be a result of interactions between genetic and environmental factors. Here, we review the role of a specific environmental factor, bisphenol A (BPA), in the pathogenesis of autoimmune diseases. BPA belongs to the group of environmental estrogens that have been identified as risk factors involved in the development of autoimmune diseases.

Prolactin variations during risperidone therapy in a sample of drug-naive children and adolescents

The aim of this prospective observational study was to investigate the variations of serum prolactin hormone (PRL) in a sample of 34 drug-naive patients (mean age 13 years) who started risperidone therapy assuming that several factors may favor the increase in serum PRL. Serum PRL and hyperprolactinemia clinical signs were examined at baseline (T0) and after almost 3 months of treatment (T1). We considered sex, pubertal status, risperidone dosage, psychiatric diagnosis, and any personal/family history of autoimmune diseases. The mean serum PRL value increased between T0 and T1 (P=0.004). The mean serum PRL was higher in females in the pubertal/postpubertal stage and for risperidone dosage up 1 mg/day. Hyperprolactinemia was found in 20% of patients at T0 and in 38% of patients at T1 (P=0.03). The mean serum PRL increase was greater in early-onset schizophrenia spectrum psychosis patients compared with no-early-onset schizophrenia spectrum psychosis patients (P=0.04). The increase in PRL was higher in patients with a personal and a family history of autoimmune diseases. This study suggests that the increase in serum PRL in patients treated with risperidone may be linked not only to the drug and its dosage but also to several risk factors such as sex, pubertal stage, psychiatric disease, and autoimmune disorders.