Hyperprolactinemia: pathophysiology and management

Assessment of the Impact of SARS-CoV-2 Infection on the Sexual Function of Women, Levels of Oxytocin and Prolactin: A Prospective Cohort Study

(1) Background: There is a lack of direct evidence on whether SARS-CoV-2 affects women's sexual function through a biological-organic mechanism. Existing studies on the topic are few and have produced contradictory results. This study aims to explore the possible relationship between sex hormones and sexual function in patients who have been infected with SARS-CoV-2. Moreover, we aimed to determine whether these changes are related to the clinical course of COVID-19 and whether they are temporary or long-lasting. (2) Methods: A study was conducted on 104 women, including 64 women infected with COVID-19 and a control group of 40 healthy women, between January 2021 and August 2022. Blood samples were collected to measure prolactin and oxytocin levels, and a clinical assessment was performed 3 and 6 months later. Sexual function self-assessment was captured based on the FSFI scale. (3) Results: Our study found that patients with severe COVID-19 had better sexual satisfaction scores one month after recovery but no discernible difference after six months. High levels of serum prolactin were observed in patients with active COVID-19 but became similar to a control group after one month and remained stable over time. Higher prolactin levels were significantly associated with increased arousal and hydration. Individuals with severe COVID-19 had notably low levels of plasma oxytocin, but there was no correlation between oxytocin levels and sexual satisfaction. (4) Conclusions: The gynecologic symptoms, as well as disturbances in oxytocin and prolactin levels, might be observed in a short time after infection. However, SARS-CoV-2 infection has no lasting effect on sexual function, oxytocin, and prolactin levels among women.

Acute retinal pigment epitheliitis during treatment of hyperprolactinaemia

BACKGROUND

Acute retinal pigment epitheliitis (ARPE) is a rare, idiopathic and self-limiting disease. The article aims to present ARPE in a patient using D2 dopamine receptor agonists for the treatment of hyperprolactinemia.

CASE PRESENTATION

A 28-year-old female during hyperprolactinaemia treatment suffered from a dyschromatopsia and a central visual field defect in the left eye. She noticed a deterioration of vision and discontinued the cabergoline administration. The woman had not been diagnosed with other chronic conditions and exhibited no symptoms of infection. Upon admission, the patient was subjected to a test for COVID-19, which was negative. The ophthalmological examination revealed a decrease in visual acuity to distance in the left eye, which amounted to 18/20 on the Snellen chart. A central scotoma was noted on the Amsler chart and a loss of pigment epithelium was visible on the fundus of the left eye. Fluorescein angiography showed a discrete window defect in the left one, with no signs of leakage. Optical coherence tomography (OCT) scans of the maculae revealed a characteristic change in the photoreceptor layer and retinal pigment epithelium (RPE) in the fovea in the left eye. The electrophysiological tests revealed decreased function of cells in macular region. A magnetic resonance imaging (MRI) of the head and orbits demonstrated an asymmetric pituitary gland without chiasm compression and discrete signal enhancement from the left optic nerve. The patient underwent observation during hospitalisation. She reported improved colour vision and a decreased scotoma in the centre of her visual field. In regular outpatient follow-ups, successive improvements in visual acuity, as well as a decreased RPE damage and outer photoreceptor layer loss during an OCT test were observed.

CONCLUSIONS

A case of ARPE is reported in a patient taking medications for hyperprolactinemia. The role of dopamine receptor antagonists in the photoreceptor function and causation of ARPE needs further evaluation.

Recent findings on hyperprolactinemia and its pathological implications: a literature review

The prolactin hormone (PRL) is often secreted by lactotrophic cells of the anterior pituitary and has been shown to play a role in various biological processes, including breast feeding and reproduction. The predominant form of this hormone is the 23 kDa form and acts through its receptor (PRLR) on the cell membrane. This receptor is a member of the superfamily of hematopoietic/cytokine receptors. PRL also has a 16 kDa subunit with anti-angiogenic, proapoptotic, and anti-inflammatory effects which is produced by the proteolytic breakdown of this hormone under oxidative stress. Although the common side effects of hyperprolactinemia are exerted on the reproductive system, new studies have shown that hyperprolactinemia has a wide variety of effects, including playing a role in the development of autoimmune diseases and increasing the risk of cardiovascular disease, peripartum cardiomyopathy, and diabetes among others. The range of PRL functions is increasing with the discovery of multiple sites of PRL secretion as well as PRLR expression in various tissues. This review summarizes current knowledge of the biology of PRL and its receptor, as well as the role of PRL in human pathophysiology.

Proton pump inhibitors therapy and risk of hyperprolactinemia with associated sexual disorders

Proton pump inhibitors (PPIs) are the most widely prescribed medications in the world. According to numerous studies, PPIs have been linked to hyperprolactinemia, which can lead to a variety of sexual and reproductive issues. This review summarizes the effects of numerous PPIs on the blood prolactin levels and associated sexual dysfunctions, which have an effect on the patient's life quality and fertility. The study is taken into account all the available resources till January 31, 2021. Out of total 364, only 27 relevant resources were involved in this review. In certain studies, short-term PPIs use has been shown to have little or no effect on the blood prolactin and other reproductive hormones levels. PPIs have been linked to the development of hyperprolactinemia in several case studies with varying degrees of the blood prolactin levels increase seen in individuals taking PPI alone or in combination with medications, like prokinetics. The relative risk of the sexual consequences development, such as gynecomastia, has been documented using lansoprazole and omeprazole in various cohort studies. On the other hand, other bits of data are insufficient to establish a definite relationship that can turn a possibility into certainty. The majority of the literature data is comprising of double-blind, randomized, crossover studies, case reports, and adverse drug reaction incidents reported to various pharmacovigilance centers. To investigate this link, high-quality studies in patients taking PPIs for a longer time period are needed. We conclude this article with a comprehensive discussion of the hyperprolactinemia clinical implications and the PPIs' function.

Unveiling the Metabolic Profile of First-Episode Drug-Naïve Schizophrenia Patients: Baseline Characteristics of a Longitudinal Study Among Han Chinese

Objective: Metabolic and other medical conditions are frequently comorbid with schizophrenia. As they might be the side-effects of antipsychotic treatment, studying first-episode drug-naïve schizophrenia (FDSZ) provides a unique opportunity to investigate a direct pathogenic link between metabolic changes and schizophrenia. Here, we presented the methods and baseline unique metabolic profile of FDSZ patients without medical comorbidities unveiling subthreshold indices of metabolic disturbances. Method: Drug-naïve individuals diagnosed with schizophrenia but without any previous medical conditions were invited to participate in the study. Participants were submitted to structured psychiatric and cognitive assessments, laboratory and neuroimaging tests. Subjects will be followed after antipsychotic treatment at 6, 24 and 48 weeks. Results: During an 8-month-period, out of 103 patients presenting with first episode psychosis, 67 subjects (43.3% men, 56.7% women) were enrolled in the study. They had a mean ± SD age of 32.1 ± 8.7 years, with a mean BMI of 21.1 kg/m² and 11.3 ± 3.6 years of schooling. Less than 1/3 reported a family history of mental illness. Upon laboratory assessment, 10.4%, 7.5%, and 11.9% of patients were identified with hyperhomocysteinemia, hypertriglyceridemia and hyperprolactinemia, respectively, with percentages of women relatively higher than men except for hypertriglyceridemia. Conclusions: First episode schizophrenia patients, especially women, present subclinical metabolic abnormalities, independent of antipsychotic treatment.

Rohypnol-induced sexual dysfunction is via suppression of hypothalamic-pituitary-testicular axis: An experimental study in rats

Sexual activity is an essential part of reproductive functions and needed for the maintenance of fertility. Drugs, particularly substances of abuse, impair male reproductive function either by interrupting hormonal functions or through the nonhormonal pathways. This study evaluated the impact of Rohypnol use in sexual behaviour. Materials and methods: Thirty adult male Wistar rats of comparable weights (180-200 g) were randomly allocated into three groups, the control and low-dose and high-dose Rohypnol-treated groups. The control group received 0.5 ml of distilled water, while the low- and high-dose Rohypnol-treated groups received 2 mg/kg b.w and 4 mg/kg b.w of Rohypnol via oral lavage once daily for 28 days. Rohypnol significantly increased mount latency, intromission latency, ejaculation latency and post-ejaculatory interval, as well as lowered mount frequency, intromission frequency and ejaculation frequency. Rohypnol-induced sexual dysfunction was found to be associated with significant suppression of circulatory follicle-stimulating hormone, luteinising hormone, testosterone and oestrogen. The present study reveals that Rohypnol induces sexual dysfunction through suppression of hypothalamic-pituitary-testicular axis. It also implicates Rohypnol as a potential candidate for drug-induced infertility.

Benign Breast Disease in Women

BACKGROUND

Most clinical breast changes in women are benign; in only 3% to 6% of cases are they due to breast cancer. How- ever, there is a lack of up-to-date, evidence-based treatment recommendations for the various benign differential diagnoses.

METHODS

Selective literature search of PubMed from 1985 to May 2019, including current national (AWMF, Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften [Association of Scientific Medical Societies in Germany]) and inter- national guidelines.

RESULTS

Mastalgia and fibrocystic changes are common (around 50% of all women over the age of 30). Fibroadenomas occur in 25% of women; they are the most common benign tumors of the breast and do not require treatment. With most benign breast changes the risk of dedifferentiation is very low. However, it is important in the differential diagnosis to distinguish between such benign changes and breast cancer or changes that carry a risk of malignancy. Complex cysts, for example, carry a risk of malig- nancy of 23% to 31%, papillary lesions 16% , and radial scars 7%. Where there is doubt, histological confirmation should be sought by means of percutaneous biopsy.

CONCLUSION

Benign breast changes can be definitively distinguished from malignant lesions through the selective use of avail- able diagnostic investigations and interdisciplinary collaboration. When lesions of uncertain malignant potential are found (B3 in the biopsy classification), complete excision is indicated. Prospective studies on the early diagnosis of breast cancer in lesions carrying a risk of malignancy are desirable.

Analysis of Catecholamines and Pterins in Inborn Errors of Monoamine Neurotransmitter Metabolism-From Past to Future

Inborn errors of monoamine neurotransmitter biosynthesis and degradation belong to the rare inborn errors of metabolism. They are caused by monogenic variants in the genes encoding the proteins involved in (1) neurotransmitter biosynthesis (like tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC)), (2) in tetrahydrobiopterin (BH₄) cofactor biosynthesis (GTP cyclohydrolase 1 (GTPCH), 6-pyruvoyl-tetrahydropterin synthase (PTPS), sepiapterin reductase (SPR)) and recycling (pterin-4a-carbinolamine dehydratase (PCD), dihydropteridine reductase (DHPR)), or (3) in co-chaperones (DNAJC12). Clinically, they present early during childhood with a lack of monoamine neurotransmitters, especially dopamine and its products norepinephrine and epinephrine. Classical symptoms include autonomous dysregulations, hypotonia, movement disorders, and developmental delay. Therapy is predominantly based on supplementation of missing cofactors or neurotransmitter precursors. However, diagnosis is difficult and is predominantly based on quantitative detection of neurotransmitters, cofactors, and precursors in cerebrospinal fluid (CSF), urine, and blood. This review aims at summarizing the diverse analytical tools routinely used for diagnosis to determine quantitatively the amounts of neurotransmitters and cofactors in the different types of samples used to identify patients suffering from these rare diseases.

The benefit and risk of stereotactic radiosurgery for prolactinomas: an international multicenter cohort study

OBJECTIVE

The most common functioning pituitary adenoma is prolactinoma. Patients with medically refractory or residual/recurrent tumors that are not amenable to resection can be treated with stereotactic radiosurgery (SRS). The aim of this multicenter study was to evaluate the role of SRS for treating prolactinomas.

METHODS

This retrospective study included prolactinomas treated with SRS between 1997 and 2016 at ten institutions. Patients' clinical and treatment parameters were investigated. Patients were considered to be in endocrine remission when they had a normal level of prolactin (PRL) without requiring dopamine agonist medications. Endocrine control was defined as endocrine remission or a controlled PRL level ≤ 30 ng/ml with dopamine agonist therapy. Other outcomes were evaluated including new-onset hormone deficiency, tumor recurrence, and new neurological complications.

RESULTS

The study cohort comprised 289 patients. The endocrine remission rates were 28%, 41%, and 54% at 3, 5, and 8 years after SRS, respectively. Following SRS, 25% of patients (72/289) had new hormone deficiency. Sixty-three percent of the patients (127/201) with available data attained endocrine control. Three percent of patients (9/269) had a new visual complication after SRS. Five percent of the patients (13/285) were recorded as having tumor progression. A pretreatment PRL level ≤ 270 ng/ml was a predictor of endocrine remission (p = 0.005, adjusted HR 0.487). An increasing margin dose resulted in better endocrine control after SRS (p = 0.033, adjusted OR 1.087).

CONCLUSIONS

In patients with medically refractory prolactinomas or a residual/recurrent prolactinoma, SRS affords remarkable therapeutic effects in endocrine remission, endocrine control, and tumor control. New-onset hypopituitarism is the most common adverse event.

The antipsychotics sulpiride induces fatty liver in rats via phosphorylation of insulin receptor substrate-1 at Serine 307-mediated adipose tissue insulin resistance

Cumulative evidence has suggested that many antipsychotics cause metabolic abnormalities. Adipose tissue insulin resistance (Adipo-IR) contributes to the development and progress of metabolic abnormalities including fatty liver by inducing excessive free fatty acid release from adipose tissue. Sulpiride is an old antipsychotic still frequently used in many developing countries. However, its adverse metabolic effects remain poorly understood. Here, chronic administration of sulpiride (80 mg/kg, subcutaneously, once daily for 6 weeks) elevated fasting insulin concentration and the index of the homeostasis model assessment of insulin resistance in rats. More importantly, sulpiride increased hepatic triglyceride accumulation and Oil Red O-stained area, indicating the induction of fatty liver by sulpiride. Sulpiride also increased plasma non-esterified fatty acid concentrations at the baseline and during an oral glucose tolerance test, the Adipo-IR index, and adipocyte size. Adipose gene expression profile revealed that sulpiride decreased mRNA and protein expression of insulin receptor substrate (IRS)-1, but not IRS-2. Furthermore, sulpiride increased phosphorylation of both Ser³⁰⁷ in IRS-1 and Ser⁴⁷³ in Akt at baseline. Co-treatment with bromocriptine (a dopamine D₂ receptor agonist) attenuated sulpiride-induced hyperprolactinemia, but it was without effect on insulin resistance and fatty liver. Therefore, the present results suggest that sulpiride induces fatty liver in rats via phosphorylation of IRS-1 at Ser³⁰⁷-mediated adipose tissue insulin resistance, in which dopamine D₂ receptor is possibly not involved. Our findings may provide new insights into the mechanisms underlying the steatotic effect of the old antipsychotic.

Prolactinoma in a Dog

A 12-year-old male Yorkshire Terrier was presented because of decreased appetite. Physical examination revealed mammary gland swelling and galactorrhea. Contrast-enhanced computed tomographic scanning of the skull indicated an enlarged pituitary gland, compatible with a pituitary tumor. The serum prolactin concentration was markedly elevated. One week after the start of treatment with the dopamine agonist cabergoline, the serum prolactin concentration normalized and the galactorrhea resolved. Cabergoline was administered for approximately 4 months and then discontinued. Subsequently, serum prolactin concentration increased again, and mammary gland swelling and galactorrhea reappeared. The dog was euthanized 10 months after the first detection of the galactorrhea because of problems not directly related to pituitary disease. Postmortem examination revealed an infiltrative adenoma of the pituitary gland with immunolabeling for prolactin. The clinical and histopathologic findings indicated the diagnosis of a functional prolactinoma in a male dog.

Chemiluminescence systems; do all lead to same results in prolactin analysis?

Background

Human prolactin (PRL) is a hormone that is mainly secreted by lactotroph cells of the anterior pituitary gland and is involved in many biological processes including lactation and reproduction. Prolactin level may be determined quantitatively in serum by many different systems including chemiluminescence systems. However, comparison of the measured values between systems is difficult.

Methods

The prolactin values obtained and compared in two chemiluminescence systems; AUTOBIO DIAGNOSTICS MICROPLATE LUMOMETER and LIAISON XL Analyzer using BioRad tri level serum quality control materials and serum samples from n = 44 female patients; (Age mean & range) = (33: 21–65) years.

Results

Obtained PRL mean and range in Autobio and Liason systems were X = 414.8 ± 230.0; Range: 25.7–980.9 μlU/mL & X = 391.7 ± 225.6; Range: 26.0–991.4 μlU/mL respectively. Both system’s results were correlated (Pearson product moment correlation r = 0.97 at p = 0.01 and Regression Analysis).

Conclusion

Because of the differences between CLIA systems the authors conclude laboratories measuring range for PRL be accomplished on particular analyzer and verified against reference intervals stated by the manufacture. More importantly, consecutive PRL level determinations and patients follow up should be performed on only one analyzer rather than different analyzers. In this regard, mentioning the method and system type on the final laboratory reports become important and verify that a laboratory considers the clinical aspects of laboratory request as well as the quality assurance in performing the PRL determination.

Paeoniflorin and liquiritin, two major constituents in Chinese herbal formulas used to treat hyperprolactinemia-associated disorders, inhibits prolactin secretion in prolactinoma cells by different mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniflorin and liquiritin are major constituents in some Chinese herbal formulas, such as Yiru Tiaojing (YRTJ) Granule (a hospitalized preparation) and Peony-Glycyrrhiza Decoction, used for hyperprolactinemia-associated disorders.

AIM OF THE STUDY

To investigate the effect of paeoniflorin and liquiritin on prolactin secretion.

MATERIALS AND METHODS

The effect of YRTJ Granule on metoclopramide-induced hyperprolactinemia was tested in rats. Paeoniflorin and liquiritin in the YRTJ Granule extract were identified and quantified by HPLC. The effects of paeoniflorin and liquiritin on prolactin secretion were examined in prolactinoma cells that were identified morphologically and by Western blot. The concentration of prolactin was determined by ELISA. The gene expression was analyzed by Western blot.

RESULTS

YRTJ Granule ameliorated metoclopramide-induced hyperprolactinemia in rats. The contents of paeoniflorin and liquiritin in YRTJ Granule were 7.43 and 2.05mg/g extract, respectively. Paeoniflorin, liquiritin and bromocriptine (a dopamine D₂ receptor (D₂R) agonist) decreased prolactin concentration in MMQ cells expressing D₂R. However, the effect of liquiritin and bromocriptine was abolished in GH3 cells lacking D₂R expression. Interestingly, paeoniflorin still decreased prolactin concentration in GH3 cells in the same manner. Furthermore, paeoniflorin suppressed prolactin protein expression, and was without effect on D₂R protein expression in both MMQ and GH3 cells.

CONCLUSIONS

The present results suggest that paeoniflorin and liquiritin play a role in YRTJ Granule-elicited improvement of hyperprolactinemia. While the effect of liquiritin is D₂R-dependent, paeoniflorin D₂R-independently inhibits prolactin secretion in prolactinoma cells that may especially benefit the hyperprolactinemic patients who are refractory to dopaminergic therapies.

Hyperprolactinaemia - a problem in patients from the reproductive period to the menopause

Hyperprolactinaemia especially affects women in reproductive age (90/100,000) but also often is diagnosed in menopause age and leads to disturbances in functioning of LH-RH neurons and, as a consequence, to a decrease of FSH and LH, which causes inhibition of oestradiol production. Prolactin is a peptide hormone, phylogenetically one of the oldest, stimulating cells of various organs, which is produced and secreted mainly by lactotrophic acidophilic cells of the anterior lobe of the pituitary. It influences the increase in the mass of the mammary glands, and stimulation and maintenance of lactation after delivery. There are a number of factors apart of pregnancy, delivery, and lactation than can influence secretion of the hormone in other physiological and pathological circumstances, like high-protein diet, stress, REM sleep, or neoplastic tumours, inflammatory diseases, chronic systematic diseases, thyroid hormonal changes, and drug intake. The purpose of this review is to summarise the current knowledge regarding the proper diagnosis and possible influence of hyperprolactinaemia on fertility and menopause symptoms and current treatment methods.

Circulating prolactin level in systemic lupus erythematosus and its correlation with disease activity: a meta-analysis

Objective

This study aimed to evaluate the relationship between circulating prolactin level and systemic lupus erythematosus (SLE), and to establish a correlation between plasma/serum prolactin levels and SLE activity.

Methods

We performed a meta-analysis comparing the plasma/serum prolactin levels in patients with SLE to controls, and examined correlation coefficients between circulating prolactin level and SLE disease activity.

Results

Twenty-five studies with a total of 1056 SLE patients and 426 controls were included. Prolactin levels were significantly higher overall in the SLE group than in the control group (standardized mean difference (SMD) = 0.987, 95% CI = 0.512–1.463, p = 4.7 × 10−5). Stratification by ethnicity showed significantly elevated prolactin levels in the SLE group in Asian, Latin American, and mixed populations (SMD = 0.813, 95% CI = 0.137–1.490, p = 0.018; SMD = 0.981, 95% CI = 0.307–1.655, p = 0.004; SMD = 1.469, 95% CI = 0.443–2.495, p = 0.005, respectively), but not in the European population. Subgroup analysis by sample size showed significantly higher prolactin levels in the SLE group by small ( n < 30) and large sample numbers ( n > 30). Meta-analysis of correlation coefficients showed a significantly positive correlation between circulating prolactin level and SLE activity (correlation coefficient = 0.379, 95% CI = 0.026–0.487, p = 4.0 × 10−9). Circulating prolactin levels were positively associated with SLE activity in European, Asian, and mixed populations (SMD = 0.532, 95% CI = 0.443–0.609  p < 1.0 × 10−8; SMD = 0.427, 95% CI = 0.240–0.583, p = 2.4 × 10−5; SMD = 0.433, 95% CI = 0.212–0.591, p = 2.7 × 10−5, respectively).

Conclusions

Our meta-analysis demonstrated that circulating prolactin levels are higher in patients with SLE, and that a significantly positive correlation exists between prolactin levels and SLE activity.

Hyperprolactinemia: pathophysiology and therapeutic approach

Prolactin (PRL) is a hormone, mainly secreted by lactotroph cells of the anterior pituitary gland. Recent studies have shown it may also be produced by many extrapituitary cells. Its well-recognized PRL plays an important role in lactation during pregnancy, but it is involved in other biological functions such as angiogenesis, immunoregulation and osmoregulation. Hyperprolactinemia is a typical condition producing reproductive dysfunction in both sexes, resulting in hypogonadism, infertility and galactorrhea. It may be also asymptomatic. Lactotroph adenomas (prolactinoma) is one of the most common cause of PRL excess, representing approximately 40% of all pituitary tumors. Several other conditions should be excluded before a clear diagnosis of hyperprolactinemia is made. Hyperprolactinemia may be secondary to pharmacological or pathological interruption of hypothalamic-pituitary dopaminergic pathways or idiopathic. Stress, renal failure or hypothyroidism are other frequent conditions to exclude in patients with hyperprolactinemia. We will review biochemical characteristics and physiological functions of that hormone. Clinical and pharmacological approach to hyperprolactinemia will also be discussed.

Prolactin and sex hormones levels in males with Parkinson's disease

BACKGROUND

The role that oestradiol and testosterone play in Parkinson's disease and their potential to influence the course of the disease has been covered in medical literature. The aim of this work was to compare oestradiol, testosterone, sex hormone-binding protein and prolactin blood levels in males affected with Parkinson's disease and in an age-matched control group, and to show possible dependence between concentrations of plasma hormones and the progression of symptoms of Parkinson's disease.

METHODS

The plasma levels of oestradiol, testosterone, prolactin and sex hormone-binding protein were examined in 36 patients affected with Parkinson's disease and in 69 age-matched control subjects, using chemiluminescent reactions. Patients with Parkinson's disease were examined using scales assessing their clinical state.

RESULTS

The level of prolactin was higher in the affected group. Concentrations of oestradiol and testosterone in the control group exceeded those found in patients. The level of sex hormones was positively correlated with better mood and quality of life in patients affected with Parkinson's disease; prolactin levels correlated negatively with sex steroid concentrations.

CONCLUSIONS

Lower blood levels of sex steroids and higher concentrations of prolactin and its antigonadotrophic activity in males affected with Parkinson's disease may result in a bigger susceptibility to the disease in men. The level of hormones may influence patients' cognition, mood and quality of life.

Symptomatic Rathke's cleft cyst with a co-existing pituitary tumor; Brief review of the literature

Pituitary adenomas and Rathke's cleft cysts (RCCs) share a common embryological origin. Occasionally, these two lesions can present within the same patient. We present a case of a 39-year-old male who was found to have a large sellar lesion after complaints of persistent headaches and horizontal nystagmus. Surgical resection revealed components of a RCC co-existing with a pituitary adenoma. A brief review of the literature was performed revealing 38 cases of co-existing Rathke's cleft cysts and pituitary adenomas. Among the cases, the most common symptoms included headache and visual changes. Rathke's cleft cysts and pituitary adenomas are rarely found to co-exist, despite having common embryological origins. We review the existing literature, discuss the common embryology to these two lesions and describe a unique case from our institution of a co-existing Rathke's cleft cyst and pituitary adenoma.

Neuroendocrine and metabolic components of dopamine agonist amelioration of metabolic syndrome in SHR rats

BACKGROUND

The hypertensive, pro-inflammatory, obese state is strongly coupled to peripheral and hepatic insulin resistance (in composite termed metabolic syndrome [MS]). Hepatic pro-inflammatory pathways have been demonstrated to initiate or exacerbate hepatic insulin resistance and contribute to fatty liver, a correlate of MS. Previous studies in seasonally obese animals have implicated an important role for circadian phase-dependent increases in hypothalamic dopaminergic tone in the maintenance of the lean, insulin sensitive condition. However, mechanisms driving this dopaminergic effect have not been fully delineated and the impact of such dopaminergic function upon the above mentioned parameters of MS, particularly upon key intra-hepatic regulators of liver inflammation and lipid and glucose metabolism have never been investigated.

OBJECTIVE

This study therefore investigated the effects of timed daily administration of bromocriptine, a potent dopamine D2 receptor agonist, on a) ventromedial hypothalamic catecholamine activity, b) MS and c) hepatic protein levels of key regulators of liver inflammation and glucose and lipid metabolism in a non-seasonal model of MS - the hypertensive, obese SHR rat.

METHODS

Sixteen week old SHR rats maintained on 14 hour daily photoperiods were treated daily for 16 days with bromocriptine (10 mg/kg, i.p.) or vehicle at 1 hour before light offset and, subsequent to blood pressure recordings on day 14, were then utilized for in vivo microdialysis of ventromedial hypothalamic catecholamine activity or sacrificed for the analyses of MS factors and regulators of hepatic metabolism. Normal Wistar rats served as wild-type controls for hypothalamic activity, body fat levels, and insulin sensitivity.

RESULTS

Bromocriptine treatment significantly reduced ventromedial hypothalamic norepinephrine and serotonin levels to the normal range and systolic and diastolic blood pressures, retroperitoneal body fat level, plasma insulin and glucose levels and HOMA-IR relative to vehicle treated SHR controls. Such treatment also reduced plasma levels of C-reactive protein, leptin, and norepinephrine and increased that of plasma adiponectin significantly relative to SHR controls. Finally, bromocriptine treatment significantly reduced hepatic levels of several pro-inflammatory pathway proteins and of the master transcriptional activators of lipogenesis, gluconeogenesis, and free fatty acid oxidation versus control SHR rats.

CONCLUSION

These findings indicate that in SHR rats, timed daily dopamine agonist treatment improves hypothalamic and neuroendocrine pathologies associated with MS and such neuroendocrine events are coupled to a transformation of liver metabolism potentiating a reduction of elevated lipogenic and gluconeogenic capacity. This liver effect may be driven in part by concurrent reductions in hyperinsulinemia and sympathetic tone as well as by reductions in intra-hepatic inflammation.

Serum prolactin concentration at presentation of non-functioning pituitary macroadenomas

OBJECTIVE

Serum PRL levels at presentation may be useful in distinguishing between disconnection hyperprolactinemia in non-secretory pituitary adenomas and prolactinomas in order to guide appropriate therapy; however, there is a debate regarding the discriminatory PRL thresholds. We aimed to examine PRL concentrations at presentation in a cohort of histologically proven non-functioning pituitary adenomas (NFPA).

DESIGN AND METHODS

Retrospective case note analysis was performed. Clinical, biochemical, histopathological and radiological data were recorded and analyzed. Complete data were available for 250 subjects with NFPA.

RESULTS

Of the study population, 44.8% were hyperprolactinemic at presentation, 55.3% of whom were female. Of those with hyperprolactinemia, 73.2% had PRL<1000 mIU/l on presentation, 24.1% had PRL between 1000 and 1999 mIU/l. Only 2.7% (no.=3 females, 1.2% whole cohort) had PRL>2000 mIU/l (94.3 ng/ml), 2 of whom were pregnant. No male subject and no subjects with an intrasellar macroadenoma had serum PRL>1000 mIU/l (47.2 ng/ml). Overall, serum PRL was not higher among 43 subjects taking medications known to raise PRL.

CONCLUSIONS

Our data support recent evidence that the serum PRL concentration is rarely >1000 mIU/l in males, or >2000 mIU/l in females, with non-functioning macroadenomas and that, once other contributing factors to the hyperprolactinemia have been excluded, a trial of dopamine agonist therapy for such lesions is indicated.

Risk of hyperprolactinemia and sexual side effects in males 10-20 years old diagnosed with autism spectrum disorders or disruptive behavior disorder and treated with risperidone

OBJECTIVE

The aim of this study was to investigate the long-term treatment effects of risperidone on prolactin levels and prolactin-related side effects in pubertal boys with autism spectrum disorders (ASD) and disruptive behavior disorders (DBD).

METHOD

Physical healthy 10-20-year-old males with ASD (n=89) and/ or DBD (n=9) chronically treated (mean 52 months, range 16-126 months) with risperidone (group 1, n=51) or not treated with any antipsychotic (group 2, n=47) were recruited to this observational study from the child psychiatry outpatient clinic. Morning non-fasting serum prolactin levels were measured and prolactin-related side effects were assessed by means of questionnaires and physical examination. Group differences were tested with Student's t, χ(2), Fisher exact, and Mann-Whitney tests, and logistic regression analysis, according to the type and distribution of data.

RESULTS

Hyperprolactinemia was present in 47% of subjects in group 1 but only in 2% of subjects in group 2 (odds ratio 71.9; 95% CI, 7.7; 676.3). Forty-six percent of subjects in group 1 had asymptomatic hyperprolactinemia. Current risperidone dose and 9-OH risperidone plasma level were significant predictors of hyperprolactinemia (p=0.035 and p=0.03, respectively). Gynecomastia and sexual dysfunction were present in 43% and 14% of the subjects in group 1, respectively, compared with 21% and 0% of subjects in group 2 (p=0.05 and p=0.01). Gynecomastia was not significantly associated with hyperprolactinemia.

CONCLUSIONS

Hyperprolactinemia is a common side effect in young males treated over the long term with risperidone. Young males treated with risperidone are more likely to report diminished sexual functioning than are those not treated with antipsychotics.

Bone mineral density in male adolescents with autism spectrum disorders and disruptive behavior disorder with or without antipsychotic treatment

OBJECTIVE

To investigate the long-term effects of antipsychotic (AP) treatment and AP-induced hyperprolactinemia on bone mineral density (BMD) and body composition in male adolescents with autism spectrum disorders (ASDs) and/or disruptive behavior disorder (DBD).

DESIGN

Physically healthy 10- to 20-year-old boys with ASD and/or DBD, chronically treated (n=56; mean 52 months, range 16-126 months) or not treated (n=47) with an AP, were recruited to this observational study. Prolactin levels and biochemical bone parameters were measured and BMD of the lumbar spine and total body, and body composition were assessed by dual-energy X-ray absorptiometry, and volumetric BMD of the lumbar spine calculated. Group differences were tested with Student's t-test, χ(2) test, Fisher exact test, and logistic regression analysis.

RESULTS

Forty-nine percent of the boys treated with an AP had hyperprolactinemia. The mean volumetric lumbar spine BMD z-score was lower (P=0.043), the total percentage of body fat z-score was higher (P=0.042), and biochemical bone marker carboxyterminal cross-linking telopeptide of bone collagen was lower in the AP-treated boys with hyperprolactinemia than in the AP-treated boys without hyperprolactinemia. Seven to 11% of the hyperprolactinemic boys had low BMD. The mean lumbar spine and total body BMD z-scores and body composition were similar in the boys who were or were not treated with an AP. The total study population had a lower mean lean tissue mass (mean z-score -0.37, P=0.004) and a higher percentage of total body fat (mean z-score 1.16, P<0.001) than healthy controls (normative data); biochemical bone parameters were within normal limits.

CONCLUSION

AP-induced hyperprolactinemia in boys with ASD or DBD may have a negative effect on lumbar spine BMD. Longitudinal studies are needed to confirm this finding and further disentangle the effects of the disorder, lifestyle, treatment, and hyperprolactinemia.

Recurrence of hyperprolactinaemia following discontinuation of dopamine agonist therapy in patients with prolactinoma occurs commonly especially in macroprolactinoma

CONTEXT

The optimal duration of dopamine agonist (DA) therapy in prolactinoma is unknown. There are concerns that despite low recurrence rates in highly selected groups, high recurrence rates after DA withdrawal may occur in routine practice.

OBJECTIVE

To explore recurrence of hyperprolactinaemia and predictive factors following DA withdrawal in patients with microprolactinoma and macroprolactinoma.

DESIGN

A retrospective study on adult patients with confirmed prolactinoma attending the Oxford Endocrine Department.

PATIENTS AND MEASUREMENTS

We identified patients with macroprolactinoma (n = 15) and microprolactinoma (n = 45) treated with DA therapy for >3 years, with a trial off DA therapy. None had other treatments. Measurements included recurrence of hyperprolactinaemia following DA withdrawal, tumour size (macroprolactinomas), duration of DA therapy, prolactin levels (baseline, during DA therapy, recurrence) and time to recurrence. Data were reported as mean (range).

RESULTS

During DA therapy, prolactin levels suppressed to normal range in all patients with macroprolactinoma and microprolactinoma, and most macroprolactinomas (n = 14) had substantial tumour shrinkage. Hyperprolactinaemia recurred in 93% of macroprolactinomas (n = 14) at 8·8 months (3-36) and 64% of microprolactinomas (n = 29) at 4·8 months (3-12). Duration of DA therapy was 7·5 years (4-15) for macroprolactinomas and 4·1 years (3-10) for microprolactinomas. Prolactin levels during DA therapy were 144 mU/l (7-336) for macroprolactinomas and 278 mU/l (30-629) for microprolactinomas. For microprolactinomas, prolactin levels during DA therapy were less suppressed in those with recurrence than in those without recurrence (P < 0·05).

CONCLUSIONS

In routine practice, hyperprolactinaemia recurs early in most macroprolactinomas (93%) and microprolactinomas (64%) following DA therapy discontinuation. For most macroprolactinomas, cessation of DA cannot be recommended even after 7 years of therapy.

Polycystic ovary syndrome or hyperprolactinaemia: a study of mild hyperprolactinaemia

Polycystic ovary syndrome (PCOS) and hyperprolactinaemia are both common causes of secondary amenorrhoea in reproductive women. The relationship between PCOS and hyperprolactinaemia has been reported with controversial results. To evaluate the clinical and laboratory features of women with mild hyperprolactinaemia and PCOS, we studied 474 Taiwan Chinese women: 101 had mild hyperprolactinaemia, 266 had PCOS and 107 were the control group. In this study, we found that 64% of the women with mild hyperprolactinaemia fulfilled the PCOS diagnostic criteria, regardless of their prolactin levels. Obese women with PCOS had significantly lower luteinising hormone (LH) and LH-to-FSH ratios than non-obese women with PCOS. Obese hyperprolactinaemic women had significantly lower follicle-stimulating hormone (FSH), but higher LH-to-FSH ratios than the non-obese hyperprolactinaemic women. For women with PCOS, the BMIs were significantly negative with LH (γ = -0.253, p < 0.001), but not with FSH (γ = -0.061, p = 0.319). For the hyperprolactinaemic women, the BMIs were significantly negative with FSH (γ = -0.353, p < 0.001), but not with LH (γ = -0.021, p = 0.837). Although PCOS-related syndrome was very prevalent in women with hyperprolactinaemia, the patterns of disturbance in gonadotropin secretion were different between the PCOS and the hyperprolactinaemia patients.

Comparison of cabergoline and bromocriptine in patients with asymptomatic incidental hyperprolactinemia undergoing ICSI-ET

We retrospectively assessed outcomes of in vitro fertilisation in groups of women with asymptomatic incidentally discovered hyperprolactinaemia (AIH) undergoing ovarian stimulation and ICSI-ET relative to the types of dopamine agonist and gonadotropin releasing hormone analogue used. Of 5840 women who underwent COH and ICSI-ET, 239 were included in the study; 122 had been treated with cabergoline, and 117 with bromocriptine, during the COH. The mean age, duration of stimulation, and total number of gonadotropin ampules employed were comparable in the two groups using the agonist and antagonist protocols, as were the number of oocytes retrieved and the proportion of mature MII and fertilised (2pn) oocytes. There were no significant differences in implantation, pregnancy, and miscarriage rates between the agonist and antagonist arms of the study. The cost of treatment was significantly higher with cabergoline than with bromocriptine (p = 0.0001). However, side effect rate was significantly higher with bromocriptine than with cabergoline (15.3% vs. 2.5%; p = 0.0004). In conclusion, we found that cabergoline and bromocriptine showed no differences in IVF outcomes and pregnancy results in patients with AIH.

A double pituitary adenoma presenting as a prolactin-secreting tumor with partial response to medical therapy. Case report

Double pituitary adenomas are difficult to recognize pre-operatively as only a single mass may be appreciated on imaging. We present herein a giant prolactin-secreting pituitary adenoma in a middle-aged man that had responded partially to dopamine agonist therapy. The excised specimen demonstrated a double adenoma. The prolactin-producing one displayed the expected morphological changes resulting from medical therapy, while the other, a gonadotroph adenoma, did not. The failure of tumor shrinkage can be attributed to the presence of a double adenoma, a previously unreported cause of failure of medical therapy in prolactinoma.

Practical guidelines for the use of new generation antipsychotic drugs (except clozapine) in adult individuals with intellectual disabilities

New generation antipsychotic (NGA) drugs introduced to the US market after clozapine (aripiprazole, olanzapine, paliperidone, quetiapine, risperidone, and ziprasidone) are frequently used in individuals with intellectual disabilities (ID). However, there is very limited research to fully establish evidence-based or personalized medicine approaches for their use in this population. These guidelines take a pragmatic approach to establishing frameworks for their use by utilizing the prescribing information and reviewing the available literature on other relevant neuropsychiatric disorders. In the absence of expert consensus guidance and well-controlled comparison trials, we present a set of guidelines to inform initiation, dosing and monitoring of use in adults. Further, in these guidelines we provide practical information on drug-drug interactions and adverse drug reactions, and a brief review of discontinuation syndromes, potential for abuse, use during pregnancy and cost considerations. We also provide drug utilization review forms for each NGA to facilitate implementation of these guidelines, these guidelines provide a practical and necessary resource for practitioners treating psychiatric disorders and challenging behaviors in adult individuals with ID.

Primary hypothyroidism in a child simulating a prolactin-secreting adenoma

OBJECTS

To report a case of primary hypothyroidism associated to hyperprolactinemia mimicking a prolactin secreting adenoma.

MATERIALS AND METHODS

A girl (10 years and 10 months old) was evaluated for hyperprolactinemia (prolactin: 317 ng/mL [1.9-25]). Diagnostic evaluation demonstrated free thyroxine (F-T4): 0.22 ng/dL (0.75-1.80) and thyroid-stimulating hormone (TSH): 135 UI/mL (0.3-5.0). Pituitary magnetic resonance imaging (MRI) showed an intrasellar and suprasellar mass measuring 1.9 x 1.7 x 1.7 cm, impinging on the optic chiasm. Due to the possibility of a pseudoprolactinoma caused by hyperplasia of the TSH and prolactin-producing cells, she was treated for the primary hypothyroidism with levothyroxine. After 2 months, F-T4, TSH, and prolactin returned to normal values. A new pituitary MRI, 8 months later, demonstrated a complete resolution of the pituitary mass confirming the initial suspicion of thyrotroph hyperplasia.

CONCLUSION

This paper illustrates the importance of thyroid function investigation in patients with hyperprolactinemia and possible prolactinoma in order to avoid unnecessary surgery.

Increased incidence of autoimmune thyroiditis in patients with antipsychotic-induced hyperprolactinemia

Prolactin (PRL) elevation in patients with prolactin-secreting pituitary tumors has been linked to increased prevalence of thyroid autoantibodies. However, the effects of antipsychotic drug-induced hyperprolactinemia (HPRL) on development of thyroid autoimmunity and also of other autoimmune phenomena have not been previously studied. To examine whether serum PRL levels were associated with the prevalence of thyroid autoantibodies in patients with schizophrenia receiving long-term antipsychotic treatment, we determined serum PRL, thyrotropin, free thyroxine levels, and the presence of antithyroid peroxidase and antithyroglobulin antibodies in 75 consecutive, clinically stable schizophrenic outpatients who had been on stable doses of antipsychotics for at least 3 months, and had no history of overt thyroid disease. We found that the prevalence of hyperprolactinemia was significantly higher in patients positive for thyroid autoantibodies, when compared with patients negative for them (p=0.045). Serum levels of prolactin were also significantly higher in patients with positivity for thyroid autoantibodies (p=0.039). In separate analyses for genders, a trend-level relationship was observed in females between increased levels of prolactin and the presence of thyroid autoantibodies (p=0.060). Our findings suggest that through the associated HPRL, long-term antipsychotic treatment can induce thyroid autoimmunity. Future research is required to investigate, whether other autoimmune processes might be triggered by antipsychotic drug-induced HPRL, and to what extent the immune alterations reported in patients with schizophrenia are related with this phenomenon.

Prolactin awareness: an essential consideration for physical health in schizophrenia

Elevations in serum prolactin levels (hyperprolactinaemia) are a common side effect of conventional and some atypical antipsychotic treatments. In patients with schizophrenia, the adverse effects of antipsychotic-induced hyperprolactinaemia on physical health (e.g. fertility problems, sexual dysfunction and reduced bone mineral density) are gaining attention. Accumulating evidence shows consistent 'prolactin-raising' effects of conventional antipsychotics and risperidone compared with other current atypical antipsychotics, which are more likely to have 'prolactin-sparing' properties. Prolactin-sparing antipsychotics (for example, aripiprazole and quetiapine) tend to show lower frequencies of hyperprolactinaemia-associated side effects. In recent studies, aripiprazole-treated patients have demonstrated lower prolactin levels compared with patients receiving other prolactin-sparing antipsychotics. There is a lack of robust recommendations for monitoring prolactin elevation among patients receiving antipsychotics. Decreasing the antipsychotic dose or switching to a prolactin-sparing medication are possible management options for antipsychotic-induced hyperprolactinaemia. There is a need to increase awareness and understanding of the impact of antipsychotic-induced hyperprolactinaemia on physical health in schizophrenia.

The prevalence of hyperprolactinemia and galactorrhea in patients with abnormal uterine bleeding

BACKGROUND

Abnormal uterine bleeding is one of the most common gynecological problems in women aged 15-45 years. The relationship of hyperprolactinemia with reproductive disorders, amenorrhea and irregular menstrual cycles has been known. The aim of the present study was to determine the frequency of hyperprolactinemia and galactorrhea in 15-45-year-old females with abnormal uterine bleeding.

METHODS

This analytic descriptive study was carried out on 100 women referred to a gynecology clinic for vaginal bleeding without any organic disorder. Consecutive sampling was performed.

RESULTS

Among the cases 61% had hyperprolactinemia and galactorrhea was reported in 48% of these patients. There was a significant association between hyperprolactinemia and galactorrhea (p = 0.003); 46% of patients with galactorrhea and 75% of patients without galactorrhea had a high level of prolactin. Galactorrhea and hyperprolactinemia had no significant association with the type of abnormal uterine bleeding. Among patients with undiagnosed vaginal bleeding, hyperprolactinemia was present in more than 50% of them and in 46% it was associated with galactorrhea.

CONCLUSION

Hyperprolactinemia that presents a gynecological problem may or may not be accompanied by galactorrhea, and galactorrhea cannot be a certain index for hyperprolactinemia.

Anejaculation as the presenting feature of pituitary microadenoma

OBJECTIVE

To describe the resolution of anejaculation associated with PRL excess by dopamine agonist treatment.

DESIGN

Case report.

SETTING

Fertility clinic.

PATIENT(S)

Two men with anejaculation, in one case with associated infertility.

INTERVENTION(S)

Dopamine agonist treatment.

MAIN OUTCOME MEASURE(S)

Resolution of anejaculation and infertility.

RESULT(S)

Endocrine investigations in both men revealed low serum T, elevated PRL, and a pituitary microadenoma. Treatment with a dopamine agonist normalized serum hormone profiles and restored sexual function, with subsequent involution of the adenoma.

CONCLUSION(S)

Prolactinoma manifesting as anejaculation is rare but responds readily to treatment with a dopamine agonist. Serum PRL should be measured in any man presenting with anejaculation.

[Early pleuropulmonary toxicity associated with cabergoline, an antiparkinsonian drug]

We report a case of pleural effusion, pericardial thickening, and pulmonary involvement in a patient with dry cough, dyspnea, edema, and changes in the skin of the lower limbs. Treatment with cabergoline (Sogilen) had been started 4 months earlier. Pleural effusion, pericardial thickening, and impaired pulmonary function (airflow obstruction, increased airway resistance, and reduced carbon monoxide diffusing capacity) were observed. The Naranjo scale pointed to a probable relationship between cabergoline and these adverse effects. We report on outcome after 2 months of follow-up, during which time there was a slow and incomplete improvement in respiratory function. This is the first case in our practice setting of early pleuropulmonary toxicity associated with cabergoline.

Pregnancy outcomes following cabergoline treatment: extended results from a 12-year observational study

OBJECTIVE

Cabergoline is a dopamine agonist used to treat hyperprolactinaemia. Because hyperprolactinaemia is a significant cause of infertility in women, cabergoline and other dopamine agonists are frequently prescribed to reduce prolactin levels and restore normal menses. They are usually discontinued shortly after the patient becomes pregnant. Although cabergoline has been used to treat hyperprolactinaemia since the mid-1990s, safety data related to maternal and foetal exposure to this agent are still limited.

DESIGN

The current prospective, observational study reports on a total of 380 pregnancies. This extends by 154 pregnancies the results of a previously published interim report on the outcomes of 226 pregnancies in women treated with cabergoline up to 1994.

MAIN OUTCOME MEASURES

Outcomes examined include the incidence of abortions and premature delivery and the number and types of foetal malformations or abnormalities.

RESULTS

Follow-up data were available for 329 pregnancies, including 258 (78%) deliveries and 71 (22%) abortions. Of the 71 reported abortions, 31 (44%) were voluntary, 30 (42%) were spontaneous miscarriages, and nine (13%) were therapeutic. Of the 258 deliveries, 250 (97%) were live deliveries, four (2%) were stillbirths, and the status of delivery was unknown for the remaining four (2%). Of the 250 live deliveries, 193 (77%) were term deliveries (gestational period > 37 weeks), 45 (18%) were preterm deliveries (gestational period < or = 37 weeks), and 62% of the infants had normal birthweights (i.e. 3-4 kg). Neonatal abnormalities were recorded for 23 (9%) of the infants with no apparent pattern in type or severity.

CONCLUSION

The results of this study suggest that foetal exposure to cabergoline through early pregnancy does not induce any increase in the risk of miscarriage or foetal malformation.

Molecular pathogenesis of human prolactinomas identified by gene expression profiling, RT-qPCR, and proteomic analyses

The molecular pathogenesis of prolactinomas has resisted elucidation; with the exception of a RAS mutation in a single aggressive prolactinoma, no mutational changes have been identified. In prolactinomas, a further obstacle has been the paucity of surgical specimens suitable for molecular analysis since prolactionomas are infrequently removed due to the availability and effectiveness of medical therapy. In the absence of mutational events, gene expression changes have been sought and detected. Using high-throughput analysis from a large bank of human pituitary adenomas, we examined these tumors according to their molecular profiles rather than traditional immunohistochemistry. We examined six prolactinomas and eight normal pituitary glands using oligonucleotide GeneChip microarrays, reverse transcription-real time quantitative polymerase chain reaction using 10 prolactinomas, and proteomic analysis to examine protein expression in four prolactinomas. Microarray analyses identified 726 unique genes that were statistically significantly different between prolactinomas and normal glands, whereas proteomic analysis identified four differently up-regulated and 19 down-regulated proteins. Several components of the Notch pathway were altered in prolactinomas, and there was an increased expression of the Pit-1 transcription factor, and the survival factor BAG1 but decreased E-cadherin and N-cadherin expression. Taken together, expression profiling and proteomic analyses have identified molecular features unique to prolactinomas that may contribute to their pathogenesis. In the current era of molecular medicine, these findings greatly enhance our understanding and supercede immunohistochemical diagnosis.

Hyperprolactinemia

In several respects prolactin is unique among anterior pituitary hormones. The primary regulation of prolactin secretion is mediated through hypothalamic inhibition, and the diagnosis of hyperprolactinemia can be established without the use of stimulation or suppression tests. Documenting the presence of hyperprolactinemia is not difficult-the challenge is in identifying the cause of the hormone hypersecretion. With immunoradiometric assays falsely low levels of prolactin are occasionally seen in patients with macroadenomas and very high serum prolactin (the hook effect). Macroprolactin should be suspected when a patient with hyperprolactinemia does not present with typical clinical symptoms, and all hyperprolactinemic sera should be screened for macroprolactin. With prolactinomas, prolactin levels generally parallel tumor size. Prolactin secreting macroadenomas are typically associated with levels that exceed 250 microg/l and may exceed 1,000 microg/l. Large non-functioning adenomas also lead to hyperprolactinemia but levels virtually never exceed 94 microg/l. Acquired and isolated prolactin deficiency is rare.

Remission of acromegaly following long-term therapy with cabergoline: report of two cases

Dopamine agonists are effective in some patients with acromegaly and in this condition treatment is considered to be chronic. We describe two acromegalic patients who responded adequately to the long-acting dopamine agonist cabergoline, but surprisingly maintained normal GH and IGF-I levels once therapy was discontinued after 42 and 76 months because of possibly related side effects. A 32-year-old woman with mild acromegaly (IGF-I: 423 microg/l, GH after OGTT: 2.5 microg/l, adenoma 4 mm) was treated with cabergoline as primary therapy and reached safe GH levels (2 microg/l or less) and normal IGF-I levels with 3.5 mg cabergoline weekly. After 42 months of therapy the patient experienced a progressive decrease of libido, which she attributed to the intake of cabergoline. After stopping medication, serum levels of GH and IGF-I remained normal during the following 2.5 years. A 53-year-old man with moderate acromegaly (serum IGF-I: 547 microg/l, GH after OGTT: 5.9 microg/l, adenoma 7 mm) preferred cabergoline as primary therapy. Serum GH levels below 2 microg/l and normal levels of IGF-I were obtained with 3.5 mg cabergoline weekly. When the patient experienced severe stomach pains after 76 months of treatment, cabergoline was held responsible and discontinued. Serum GH and IGF-I did not increase again and stayed at the same level during a follow-up of 5.5 years. These two cases demonstrate that acromegalic patients with a good response to cabergoline may occasionally remain in remission after stopping therapy. This phenomenon has previously only been described in patients with a prolactinoma.