Insulin-like Growth Factor 1, but Not Insulin-Like Growth Factor-Binding Protein 3, Predicts Central Precocious Puberty in Girls 6–8 Years Old: A Retrospective Study

<b><i>Background:</i></b> Central precocious puberty (CPP) in females is characterized by thelarche before 8 years of age. Evidence of reproductive axis activation confirms the diagnosis (basal serum luteinizing hormone (LH) ≥0.3 IU/L or LH-releasing hormone (LHRH)-stimulated LH ≥5 IU/L). Stimulation testing is the diagnostic gold standard but is time-consuming and costly. Serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) are increased in girls with CPP. <b><i>Objective:</i></b> The aim of the study was to assess the utility of serum IGF-1 and IGFBP-3 in identifying CPP in girls aged 6–8 years. <b><i>Methods:</i></b> The study was a single-center retrospective study. Girls with confirmed CPP (<i>n</i> = 44) and isolated premature precocious adrenarche/ precocious thelarche (PA/PT, <i>n</i> = 16) had baseline biochemical profiling and LHRH stimulation testing. Serum IGF-1 and IGFBP-3 results were converted to standard deviation scores (SDS). Correlations were calculated and receiver operating characteristic curves were plotted. <b><i>Results:</i></b> Girls with CPP had higher basal and peak LH, IGF-1 SDS, and growth velocity (<i>p</i> &#x3c; 0.05). IGF-1 SDS correlated positively with basal and peak LH (<i>p</i> &#x3c; 0.05). IGF-1 SDS (1.75–2.15) differentiated CPP and PA/PT with 89% sensitivity and 56% specificity (basal LH) and 94% specificity and 55% sensitivity (peak LH). IGFBP-3 SDS did not differ between groups or by CPP parameters. <b><i>Conclusions:</i></b> In clinical practice, IGF-1 SDS may be an additional tool for identifying CPP in girls aged 6 to 8 years when baseline clinical and laboratory diagnostic criteria are inconclusive, possibly avoiding more time-consuming and costly procedures.

An Ultrasensitive Routine LC-MS/MS Method for Estradiol and Estrone in the Clinically Relevant Sub-Picomolar Range

Background Current analytical routine methods lack the sensitivity to monitor plasma estrogen levels in breast cancer patients treated with aromatase inhibitors. Such monitoring is warranted for premenopausal patients treated with an aromatase inhibitor and an LH-releasing hormone analogue in particular. Therefore, we aimed to develop a routine tandem mass spectroscopy combined with liquid chromatography (LC-MS/MS) method for estradiol (E2) and estrone (E1) for use in the sub-picomolar range. Method Calibrators, quality controls (QC), or serum samples were spiked with isotope-labeled internal standard and purified by liquid-liquid extraction. The reconstituted extracts were analyzed by LC-MS/MS in negative electrospray ionization mode. QCs at 6 levels made from pooled patient sera were used to validate the accuracy, sensitivity, and precision of the method. Results We achieved limits of quantification of 0.6 pmol/L (0.16 pg/mL) for E2 and 0.3 pmol/L (0.07 pg/mL) for E1. The coefficient of variation was below 9.0% at all QC levels for E2 (range, 1.7-153 pmol/L), and below 7.8% for E1 (range, 1.7-143 pmol/L). The method is traceable to the E2 reference standard BCR576. Reference ranges for E2 and E1 in healthy, postmenopausal women were obtained, for E2: 3.8 to 36 pmol/L, for E1: 22 to 122 pmol/L. We measured and confirmed ultra-low E2 and E1 concentrations in sera from patients on the aromatase inhibitors letrozole or exemestane. Conclusion This ultrasensitive LC-MS/MS method is suitable for routine assessment of serum E1 and E2 levels in breast cancer patients during estrogen suppression therapy. The method satisfies all requirements for measurement of E2 in the clinical setting as stated by the Endocrine Society in 2013. Precis We report an ultrasensitive LCMS/MS routine assay that measures pretreatment and suppressed levels of estradiol/estrone during aromatase inhibitor treatment of postmenopausal breast cancer patients.

SAT-LB1 Detection of Serum Macro-Luteinizing Hormone

Macromolecules of prolactin (PRL) and thyrotropin (TSH), so called macro-PRL and macro-TSH, respectively, are rarely detected in the patients’ serum containing high concentrations of these hormones. The macromolecules are involved in increasing the serum concentrations due to aggregation with the autoantibodies in serum. Here we show a case having macromolecules of luteinizing hormone (LH), possibly due to the complex to immunoglobulin-G (IgG). A 35-year-old Japanese female who has complained menstrual irregularity and had a past surgical history of thyroid cancer was referred to our hospital. Laboratory examination showed an extremely high concentration of serum LH (&gt;200 mIU/ml), while serum levels of follicle-stimulating hormone, estradiol, thyroid hormones, human chorionic gonadotropin, testosterone, and prolactin were all within the normal ranges. MRI study showed a normal pituitary shape without any tumorous lesion. Responses of gonadotropins to LH-releasing hormone (LHRH) stimulation were marginally blunted but showed an LH-dominant pattern such as polycystic ovary syndrome. We suspected the presence of macro-LH because of the divergence between the clinical features and the LH level. Of note, the recovery rate of LH levels after precipitation with polyethylene glycol (PEG) was less than 5%, and the gel-filtration analysis further demonstrated an LH peak slightly earlier fraction than IgG. One case report documented the presence of macro-LH in the serum from a young female patient complicated with autoimmune thyroiditis, suggesting the formation of macro-LH related to some latent autoimmune diseases. To assume macro-LH and to re-examine LH levels after serum precipitation by PEG or protein A/G and fractionation are important to avoid unnecessary treatment to increased LH conditions. In clinical practice, we should suspect the presence of macro-LH, if serum LH levels are unexpectedly high compared to the clinical signs.

Manganese-Stimulated Kisspeptin Is Mediated by the IGF-1/Akt/Mammalian Target of Rapamycin Pathway in the Prepubertal Female Rat

Low-dose administration of manganese chloride (MnCl2) causes release of hypothalamic LH-releasing hormone (LHRH) and advances puberty in rat. Recently, this element was shown to up-regulate mammalian target of rapamycin (mTOR), kisspeptin gene (KiSS-1), and LHRH gene expressions in the brain preoptic area (POA)/anteroventral periventricular (AVPV) nucleus. Because these genes are critical for puberty, this study was conducted to identify the upstream mechanism by which Mn activates the mTOR/KiSS-1 pathway. On day 12, immature female rats began receiving a daily supplemental dose of 10 mg/kg of MnCl2 or saline by gavage, and POA/AVPV tissues were collected on day 29 for specific protein assessments. Another experiment assessed in vitro IGF-1 release in response to Mn and assessed signal transduction pathways in the POA/AVPV region after Mn delivery into the third ventricle. Chronic Mn exposure increased (P &lt; .05) basal expressions of mTOR and kisspeptin proteins. Mn increased protein kinase B (Akt) and Ras homolog enriched in brain, both capable of activating mTOR. Central Mn delivery increased expressions of phosphorylated IGF-1 receptor (IGF-1R) (P &lt; .05) and Akt (P &lt; .01) in the POA/AVPV region. The previous central delivery of JB1, an IGF-1R antagonist, blocked Mn-induced expressions of both phosphorylated IGF-1R and Akt. Downstream to Akt, centrally administered Mn increased tuberous sclerosis complex 2 (P &lt; .05), Ras homolog enriched in brain (P &lt; .01), mTOR (P &lt; .05), and kisspeptin (P &lt; .05). Finally, we observed that the early puberty induced by Mn was blocked by the administration of an mTOR inhibitor. These results suggest that Mn acts, at least in part, through the IGF-1/Akt/mTOR pathway to influence prepubertal kisspeptin and LHRH.

Preoperative Plasma Levels of Total Testosterone Associated with High Grade Pathology-Detected Prostate Cancer: Preliminary Results of a Prospective Study in a Contemporary Cohort of Patients

Objectives: To investigate the associations, if any, between preoperative plasma levels of total testosterone (TT) and pathology Gleason score (pGS) in a contemporary cohort of prostate cancer (PCa) patients. Materials and Methods: Between November 2014 and June 2015, plasma levels of TT were measured in 142 patients who underwent radical prostatectomy. Exclusion criteria were as follows: 5α-reductase inhibitors, LH-releasing hormone analogues, or testosterone replacement treatment. The entire cohort, assessed by continuous and categorical variables, was classified into two groups according to the pGS that included low-intermediate (pGS 6-7) and high grade (pGS > 7) cases. TT was evaluated as a continuous variable. Results: The cohort included 128 cases. High grade PCa was detected in 28 (21.8%) patients. Median plasma levels of both TT and prostate specific antigen (PSA) were significantly higher in these cases. In the clinical multivariate model, independent and positive predictors of pGS > 7 were TT (p = 0.041; OR = 1.004), PSA (p = 0.006; OR = 1.191), and bGS > 6 (p = 0.004; OR = 5.0); that is, a single unit increase in TT plasma levels increases the odds of having high grade PCa by 4%. Conclusion: In a contemporary cohort of patients, preoperative plasma levels of TT directly and independently associated with high grade PCa. High baseline plasma levels of TT might have clinical applications for managing PCa. New and well designed prospective studies dealing with this subject are required.

Variations of serum testosterone levels in prostate cancer patients under LH-releasing hormone therapy: an open question

The hypothesis ‘the lower the better when achieving castration levels of testosterone’ is based on the data from second-line hormonal manipulation and its molecular basis, and on better oncological results reported for lower castration levels in prostate cancer (PCa) patients, including those achieved with maximal androgen blockade. In this regard, the equivalence of surgical and different pharmacological castrations has been controversial. The modified amino acid structure that makes LH-releasing hormone (LHRH) analogs more potent than LHRH, and the method of delivering the analogs impacts on bioavailibility and potentially causes differences in androgen levels and in its final oncological efficacy. In addition to this, there is a myriad of circumstances, such as those related to ethnic variations and co-morbidities, which uniquely impact on the pharmacological approach in a highly heterogeneous population of castration-resistant prostate cancer (CRPC) patients. Ineffective testosterone suppression through hormonal escape is currently poorly recognized and may result in increased PCa mortality. Until now, the optimal serum testosterone level in patients under castration, and the impact of its variations in patients under LHRH therapy, remain open questions and have been merged to a broad spectra of patients who are highly heterogeneous. This heterogeneity relates to a number of mechanisms regarding response to treatment, which influences the biology of the relapsing tumor and the sensitivity to subsequent therapies in the individual patient. The rationale to achieve testosterone levels below 20–50 ng/dl warrant further investigation as these levels have recently rescued CRPC patients. In the last few years and months, important advancements in prostate cancer treatment have been achieved. Nevertheless, these advances are measured in a few months of additional survival and under high costs, not available to most of the world population, compared with the benefits of hormonal manipulation that are measured in years, there is a huge potential for accessible and durable effect expansion and optimization of treatment, particularly with the current tendency of a more individual approach.