Premature pubarche as a first presentation of pituitary macroprolactinoma

Prolactin and Adrenal Androgens During Adrenarche

Introduction

Premature adrenarche (PremA), is associated with increased adiposity and in girls to earlier puberty and adverse metabolic profiles. Recently LC‐MS/MS studies demonstrated adrenal production of more potent androgens: 11‐oxygenated C19 steroids. Defining the mechanisms that regulate adrenal 11‐oxygenated C19 steroids production has been elusive. We recently showed that genetic determinants of DHEAS during adrenarche differed from those during adulthood. One highly significant variant was at the prolactin receptor which is strongly expressed in human adrenal tissue. The aim of this study is to test whether an association exists between DHEAS/11‐oxygenated C19 steroids and prolactin concentrations in pre‐pubertal girls.

Methods

Two hundred and forty four prepubertal girls recruited within the ‘the Food and Environment Chilean Cohort,’ with normal birth weight (3.37 ± 0.02 Kg) were examined at 6.7 ± 0.6 years, including anthropometry and blood sampling. DHEAS and 11‐oxygenated C19 steroids were measured by LC‐MS/MS. Girls were categorized according to the DHEAS concentrations in normal DHEAS (ND, < 75th percentile for the population) or high DHEAS (HD, ≥ 75th percentile). This definition of adrenarche subgroups allows identification of PremA independently from other factors influencing clinical manifestations (i.e ethnicity, tissue sensitivity).

Results

None of the girls presented clinical evidence of pubarche. At this age mean DHEAS concentration was 16.4 (9.6, −25) μg/dL and the 75th percentile set at 25.0 μg/dL. Girls with HD had higher weight (1.3 ± 1.2 vs. 0.7 ± 1.1, p < 0.001), height (0.6 ± 1.0 vs. 0 ± 0.9, p < 0.001) and BMI (1.3 ± 1.2 vs. 0.9 ± 1.1, p < 0.01) SDs compared to ND. The concentrations of all 11‐oxygenated C19 steroids (ng/mL) were higher in girls with HD compared to girls with ND: 11KA by 16% [0.14 (0.12, 0.16) vs. 0.12 (0.10, 0.14)], 11OHA by 43% [0.07 (0.05, 0.08) vs. 0.04 (0.03, 0.05)], 11KT by 35% [0.19(0.15, 0.25) vs. 0.14 (0.11, 0.19)] and 11OHT by 30% [0.03 (0.02, 0.05) vs. 0.03 (0.01, 0.04)]. DHEAS levels correlated with each of the 11‐oxygenated C19 steroids both in the raw and in fully adjusted model. Prolactin levels [6.5 (4.4, 10.7) vs. 5.7 (4.1, 9.3)] ng/mL and insulin [7.2 (5.7, 8.7) vs. 6.8 (5.3, −9.4)] μUI/mL did not differ in HD compared to ND girls. Prolactin levels were not associated with DHEAS concentrations but significantly associated with 11KA (p < 0.001) even after adjustment by covariates and was close to the limit of significance in the fully adjusted model for 11OHA (p = 0.051).

Conclusions

Our observations confirm that 11KT is the dominant bioactive androgen in children during adrenarche and PremA. Prolactin levels are directly correlated to the concentrations of the adrenal bioactive androgens. Conditions or medications that increase prolactin concentrations during childhood could have a role in PremA.

Case Report: Multiple prolactinomas in a young man with Kallmann syndrome and familial hypocalciuric hypercalcemia

Introduction

The occurrence of prolactinomas in sex hormone treated patients with central hypogonadism is extremely rare.

Case presentation

We present a Caucasian male patient who was diagnosed with Kallmann syndrome (KS) at age 15 years. Testosterone treatment was started. At age 26 the patient presented with mild headache. MRI revealed two separate pituitary adenomas along with the absence of the olfactory bulbs. Given the presence of marked hyperprolactinemia (17x upper limit of the reference range) the diagnosis prolactinoma was made and treatment with cabergoline was started which resulted in a complete biochemical response and in marked reduction of both adenomas in size. Hypogonadism persisted and testosterone replacement therapy was continued. Genetic testing of genes associated with pituitary tumors, Kallmann syndrome and idiopathic hypogonadotropic hypogonadism was negative. Mild concomitant hypercalcemia in accordance with familial hypocalciuric hypercalcemia (FHH) prompted mutation analysis of the calcium receptor (CASR) gene which yielded a pathogenic inactivating variant.

Discussion/conclusion

The presence of two separate prolactinomas in a patient with KS has not yet been reported in the literature. The effect of sex hormone treatment of KS patients on the possible development of prolactinoma is unknown at present. The occurance of multiple prolactinomas in our patient suggests increased susceptibility. Although CaSR is expressed in GnRH neurons in mouse brain and CaSR deficient mice have a reduced hypothalamic GnRH neuronal population, the relevance of the CASR gene variant in our patient for the KS phenotype is unclear at present.

ACTH and prolactin synergistically and selectively regulate CYP17 expression and adrenal androgen production in human foetal adrenal organ cultures

OBJECTIVE

The essential role of ACTH on the growth and function of the human foetal adrenal (HFA) has long been recognized. In addition, many studies have suggested a role of the pituitary hormone prolactin (PRL) in the regulation of the HFA, but the effects of this hormone on steroidogenesis and gene expression are still unknown. Our objective was to investigate the effect of ACTH and PRL on the steroidogenic capacities of the HFA.

DESIGN

In vitro/ex vivo experimental study.

METHODS

We used a hanging drop in vitro organ culture system. First trimester HFA samples were cultured for 14 days in basal conditions or treated with ACTH, PRL, or a combination of the 2 (3 to 11 replicates depending on the experiment). Steroids were measured by liquid chromatography/tandem mass spectrometry or immunoassay, gene expression by RT-qPCR, and protein expression by immunoblot.

RESULTS

ACTH significantly increased corticosterone, cortisol, and cortisone production, both by itself and when used together with PRL. PRL stimulation by itself had no effect. Combined stimulation with ACTH + PRL synergistically and selectively increased adrenal androgen (DHEAS and Δ4-androstenedione) production and CYP17A1 expression in the HFA, while treatment with each single hormone had no significant effect on those steroids.

CONCLUSIONS

These results have important implications for our understanding of the hormonal cues regulating adrenal steroidogenesis in the HFA during the first trimester in physiological and pathological conditions and warrant further studies to characterize the molecular mechanisms of converging ACTH and PRL signalling to regulate CYP17A1 expression.

Gender differentials in the timing and prognostic factors of pubarche in Nigeria

Paucity of data exists on the timing of puberty, particularly the pubarche, in developing countries, which has hitherto limited the knowledge of the timing of pubarche, and assistance offered by physicians to anxious young people in Nigeria. Factors associated with the timings of puberty and pubarche are not well documented in Nigeria. We hypothesized that the timing of pubarche in Nigeria differs by geographical regions and other characteristics. We assessed the timing of pubarche among adolescents and young adults in Nigeria and identified prognostic factors of the timing by obtaining information on youths' sexual and reproductive developments in a population survey among in-school and out-of-school youths aged 15 to 24 years in Nigeria. A total of 1174 boys and 1004 girls provided valid information on pubarche. Results of time-to-event analysis of the data showed that mean age at pubarche among males aged 15 to 19 years and 20 to 24 years was 13.5 (SD = 1.63 years) and 14.2 (SD = 2.18 years) (respectively) compared with 13.0 (SD = 1.57 years) and 13.5 (SD = 2.06 years) among females of the same age. Median time to pubarche was 14 (Interquartile range (IQR) = 3) years and 13 (IQR = 3) years among the males and females, respectively. Cumulatively, 37% of the males had attained pubarche by age 13 years versus 53% among females, 57% vs 72% at age 14, and 73% vs 81% at age 15. The likelihood of pubarche among males was delayed by 5% compared with females (Time Ratio (TR) = 1.05: 95% CI = 1.03-1.05). Every additional one-year in the ages of both males and females increases the risk of pubarche by 1%. Similar to the females, males residents in Northeast (aTR = 1.14, 95% CI: 1.07-1.21), in the Northwest (aTR = 1.20, 95% CI: 1.13-1.27) and in the Southwest (aTR = 1.18, 95% CI: 1.11-1.26) had delayed pubarche than males from the South East. Yoruba males had delayed pubarche than Ibo males (aTR = 1.06, 95% CI: 1.01-1.12). Age at pubarche among adolescents and young adults in Nigeria differed among males and females with earlier onset among females. Pubarche timing varied mainly by ethnicity, region, and location of residence. Our findings will aid medical practitioners in providing appropriate advice and support on pubarche-related issues among adolescents in Nigeria as it could help douse pubarche anxiousness in relation to request for medical assistance.

Prolactin as an adrenocorticotropic hormone: Prolactin signalling is a conserved key regulator of sexually dimorphic adrenal gland function in health and disease

A large number of previous reports described an effect of the pituitary hormone prolactin (PRL) on steroid hormone production by the adrenal cortex. However, those studies remained anecdotal and were never converted into a conceptual and mechanistic framework, let alone being translated into clinical care. In the light of our recently published landmark study where we described PRL signalling as a pivotal regulator of the sexually dimorphic adrenal phenotype in mouse and of adrenal androgen production in humans, we present here the overarching hypothesis that PRL signalling increases the activity of Steroidogenic Factor-1 (SF-1/NR5A1), a transcription factor that has an essential role in adrenal gland development and function, to regulate adrenal cortex growth and hormonal production in physiological and pathological conditions. PRL can then be considered as a bona fide adrenocorticotropic hormone synergizing with ACTH in the endocrine control of adrenal cortex function.

Delayed pubarche

In healthy adolescents, delayed pubarche is generally a benign condition that is caused by a physiological discrepancy between gonadarche and adrenarche. In presence of other clinical signs and symptoms, delayed pubarche can be caused by single or multiple hormones deficiency (such as adrenal insufficiency, panhypopituitarism and hypothyroidism) and/or genetic conditions (Turner syndrome, androgen insensitivity syndrome). Exposition to endocrine disruptors has also been described as a possible cause of delay of pubic hair development. Basic blood tests, karyotype and first level imaging studies are helpful in the differential diagnosis.