Establishing reference intervals for sex hormones on the analytical platforms Advia Centaur and Immulite 2000XP

Normative range of various serum hormonal parameters among Indian women of reproductive age: ICMR-PCOS task force study outcome

Background

The hormonal profile varies considerably with age, gender, ethnicity, diet or physiological state of an individual. Limited population-specific studies have studied the variations in hormonal parameters among apparently healthy women. We aimed to analyse the biological reference interval for various hormonal parameters in the reproductive-aged healthy Indian women.

Methods

Out of 3877 participants that were clinically evaluated, 1441 subjects were subjected to laboratory investigations. All participants underwent a detailed clinical, biochemical and hormonal profiling. The hormone analysis was carried out at a single centre using a uniform methodology. Among the participants evaluated for biochemical and hormonal parameters, subjects that presented any abnormal profile or had incomplete investigations (n = 593) were excluded for further analysis.

Findings

The mean age (±SD) of the subjects retained in the final analysis (n = 848) was 29.9 (±6.3) years. In the present study, the biological reference interval (2.5th-97.5th centile) observed were: serum T4: μg/dL (5.23-12.31), TSH: μg/mL (0.52-4.16) and serum prolactin: ng/mL (5.13-37.35), LH: mIU/mL (2.75-20.68), FSH: mIU/mL 2.59-15.12), serum total testosterone: ng/mL (0.06-0.68), fasting insulin: mIU/mL (1.92-39.72), morning cortisol: μg/dL (4.71-19.64), DHEAS:μg/dL (50.61-342.6) and SHBG: nmol/L (21.37-117.54). Unlike T4, TSH, LH, and E2, the biological reference interval for prolactin, FSH, testosterone, C-peptide insulin and DHEAS varied when the subjects were stratified by age (p < 0.05). The comparative analysis showed marginal differences in the normative ranges for the hormones analysed among different populations.

Interpretation

Our first large composite data on hormonal measures will benefit future endeavours to define biological reference intervals in reproductive-aged Indian women.

Funding

The study was financially supported by the grant-in-aid from ICMR vide file No:5/7/13337/2015-RBMH.

[Determination of prolactin reference intervals in different age groups]

BACKGROUND

Clinical diagnostic laboratories (CDL) have at their disposal various automated systems for the measurement of biochemical parameters and markers such as prolactin. Each of the test systems manufactures offers its own alternate design of the method, which makes standardization difficult. In endocrinological practice, the problem of result discrepancies often arises. In hormonal assays, the clinical picture of patients sometimes does not correspond to the reference values provided by the manufacturers, which determines the need to develop the method-specific reference values for a specific population. The difficulty in interpreting basal prolactin levels is not only due to a transient increase in the hormone levels caused by stress or excessive physical exertion, but also due to a significant variability of indicators in the same patient, even if all recommendations for blood sampling are followed.

AIM

The aim of the study to determine the reference values in serum samples of women, men and children of different age groups for the VITROS Immunodiagnostic Systems and compare the results with the "expected prolactin levels" recommended by the method manufacturerMATERIALS AND METHODS: The monocentric study included 879 serum samples of apparently healthy subjects who were admitted to the Endocrinology Research Center. Measurements were performed using the VITROS ECi 3600 automatic chemiluminescence analyzer (Ortho-Clinical Diagnostics, Great Britain).

RESULTS

For adult men and women reference values were 66-436 and 94-500 mIU/l respectively. When comparing the results of prolactin determination in women and men of the studied cohort with the "expected values" of the VITROS ECi 3600 manufacturer a systematic shift towards an increase in lower and upper limits of the reference values was found in both -cohorts.

CONCLUSION

The obtained reference values of prolactin can be use in the determination of prolactin in the Russian population for VITROS ECi 3600 Immunodiagnostic Systems.

Physiological Rhythms and Biological Variation of Biomolecules: The Road to Personalized Laboratory Medicine

The concentration of biomolecules in living systems shows numerous systematic and random variations. Systematic variations can be classified based on the frequency of variations as ultradian (<24 h), circadian (approximately 24 h), and infradian (>24 h), which are partly predictable. Random biological variations are known as between-subject biological variations that are the variations among the set points of an analyte from different individuals and within-subject biological variation, which is the variation of the analyte around individuals’ set points. The random biological variation cannot be predicted but can be estimated using appropriate measurement and statistical procedures. Physiological rhythms and random biological variation of the analytes could be considered the essential elements of predictive, preventive, and particularly personalized laboratory medicine. This systematic review aims to summarize research that have been done about the types of physiological rhythms, biological variations, and their effects on laboratory tests. We have searched the PubMed and Web of Science databases for biological variation and physiological rhythm articles in English without time restrictions with the terms “Biological variation, Within-subject biological variation, Between-subject biological variation, Physiological rhythms, Ultradian rhythms, Circadian rhythm, Infradian rhythms”. It was concluded that, for effective management of predicting, preventing, and personalizing medicine, which is based on the safe and valid interpretation of patients’ laboratory test results, both physiological rhythms and biological variation of the measurands should be considered simultaneously.

Reference intervals of the sex hormonal profile in healthy women: A retrospective single-center study in Peru

The female hormonal profile is of utmost importance for the assessment of the endocrinological functional status and the diagnosis of diseases. The analysis must delimit their normality intervals based on the manufacturer's cut-off points. Due to not all intervals can be evaluated before use, it is imperative to verify the reference intervals to achieve uniformity in the interpretation of results in the female population. We determine the reference intervals of five female sex hormones [Follicle Stimulating hormone (FSH), Estradiol, Luteinizing Hormone (LH), Prolactin, and progesterone] using electrochemiluminescence in the Cobas e411 (Roche). We included female patients >18 years old, between the 3rd and 15th day of the menstrual cycle (follicular phase) and had no previous medical history or recent medication. For reference intervals analysis, we followed the recommendations of the CLSI C28-A3 guideline. The average concentration for FSH, progesterone, LH, prolactin and estradiol were 11.48 ± 21.10 mIU/ml, 8.19 ± 11.90 ng/ml, 10.98 ± 11.55 ng/ml, 25.05 ± 32.74 ng/mL, and 147.08 ± 473.8 pmol/mL, respectively. Eighty per cent of parameters showed a satisfactory transfer for the manufacturer's reference intervals, except for estradiol, which had 85.5% of transferred values. Our results suggest that 4/5 sex hormones were found within the manufacturer's reference intervals and can be quantified in Peruvian women, ensuring the quality of their results. However, it is necessary to determine the estradiol with other reagents and assays since we show errors in the transfer of intervals.

Estrogen Inhibits Epithelial Progesterone Receptor-Dependent Progestin Therapy Efficacy in a Mouse Model of Cervical Cancer

Although the uterine cervix responds to the female sex hormone change, the role of progesterone in cervical cancer is poorly understood. It has been shown that medroxyprogesterone acetate (MPA) regresses cervical cancer in the transgenic mouse model expressing human papillomavirus type 16 E6 and E7 oncogenes. As MPA interacts most strongly with progesterone receptor (PR), we reasoned that PR would contribute to MPA-induced regression of cervical cancer. We also hypothesized that estrogen influences the therapeutic activity of MPA because it promotes cervical cancer growth in the same mouse model. The present study showed that the deletion of Pgr in the cervical cancer cells ablated the MPA's therapeutic effect in the human papillomavirus transgenic mouse model. Additionally, estrogen attenuated cancer regression by MPA in the same model system. These observations indicate that MPA can effectively regress cervical cancer only when cancer cells express PR and estrogen levels are low. These results suggest that, if translatable, MPA should be administered when estrogen levels are low in patients with PR-positive cervical cancer.

The impact of type 1 diabetes mellitus on male sexual functions and sex hormone levels

Little is known about type 1 diabetes mellitus (T1DM) impact on the male sexual and reproductive functions. We aim to evaluate the influence of T1DM on male sexual function, quality of sexual life, and sex hormone levels. A total of 57 male patients aged 18 to 50 years (mean = 33) with T1DM (duration mean = 15 years) had a medical examination and completed a set of questionnaires - International Index of Erectile Function-5 (IIEF-5), Beck Depression Inventory (BDI) and Sexual quality of life questionnaire male (SQoL-M). The prevalence of erectile dysfunction was 28.1% (IIEF-5 ≤21). Patients without diabetic nephropathy had better erectile function (p = 0.008). Subjects with better glycemic control (HbA_1c <65 mmol/mol) had also better erectile function (p = 0.041). At least 8.8% patients had retrograde ejaculation. Blood serum levels of sex hormones were determined and compared to laboratory reference values of healthy men. Total testosterone level was not significantly changed, sex hormone binding globulin was higher (p < 0.001) and its level correlated with daily insulin dose adjusted to body weight (p = 0.008). Free androgen index and calculated free testosterone were lower (p = 0.013; p < 0.001), estradiol was not significantly changed, LH was higher (p < 0.001), FSH was unchanged, and prolactin was higher (p < 0.001). Prostate-specific antigen (PSA) negatively correlated with HbA_1c (p < 0.001). To conclude, we found significant changes in sexual functions and sex hormone blood concentrations that indicate impairment of sexual and reproductive functions in T1DM males.

Establishing reference intervals for sex hormones and SHBG in apparently healthy Chinese adult men based on a multicenter study

Background:

Measuring sex hormones is essential in diagnosing health issues such as testicular dysfunction, male infertility and feminization syndrome. However, there are no reports on reference intervals (RIs) in Chinese men. We conducted a nationwide multicenter study to establish RIs for seven sex hormones (luteinizing hormone [LH], follicle-stimulating hormone [FSH], prolactin [PRL], total testosterone [TT], free testosterone [FT], bioavailable testosterone [BAT] and estrogen [E2]), as well as sex hormone-binding globulin (SHBG).

Methods:

In 2013, 1043 apparently healthy adult men from five representative cities in China (Beijing, Hangzhou, Guangzhou, Dalian and Urumqi) were recruited; hormones were measured using an automated immunoassay analyzer. Multiple regression analysis (MRA) was performed to identify sources of variation (SVs) that might influence the hormone serum levels. RIs were computed using the parametric method.

Results:

Dalian and Hangzhou had significantly higher E2 values than other cities; age was a major source of variation for FSH, LH, PRL, SHBG, FT and BAT. FSH, LH and SHBG increased significantly with age, while PRL, FT and BAT decreased with age. TT showed no significant age-related changes. Median (RIs) derived without partition by age were as follows: FSH, 5.6 (1.9–16.3) IU/L; LH, 4.2 (1.6–10.0) IU/L; PRL, 189 (88–450) mIU/L; E2, 85 (4.7–195) pmol/L; SHBG, 29.4 (11.5–66.3) nmol/L; TT, 15.6 (7.4–24.5) nmol/L; FT, 0.31 (0.16–0.52) nmol/L; and BAT, 8.0 (3.7–13.2) nmol/L. RIs were also derived in accordance with between-city and between-age differences.

Conclusions: RIs were established for sex hormones and SHBG in apparently healthy Chinese men in consideration of age.

The Simultaneous measurement of serum testosterone and 5α-dihydrotestosterone by gas chromatography-mass spectrometry (GC-MS)

BACKGROUND

Simultaneous measurement of testosterone (T) and 5α-dihydrotestosterone (DHT) is important for diagnosing androgen deficiency states and hyperandrogenism in males and females, respectively. However, immunoassays used for T and DHT determination suffer from inadequate specificity and sensitivity, while tandem mass spectrometry is expensive and demanding in use.

METHODS AND RESULTS

We developed a selective gas chromatography-mass spectrometry (GC-MS) method for parallel T and DHT measurement. The assay showed a linear response up to 46.5nmol/L, intra- and interassay imprecision and inaccuracy <15% and recoveries in spiked samples >90% for both analytes. The limit of quantitation was 0.117nmol/L for T and 0.168nmol/L for DHT. Comparison with immunoassays revealed good agreement for T in males, but a bias in favour of immunoassays at low concentrations for T in females and DHT in both sexes. We established reference ranges for T and DHT and suggest interval partitioning for T according to age in men and menstrual cycle in women. Assay validation in a clinical setting suggests that measuring DHT or T/DHT ratio may help identify patients with polycystic ovary syndrome.

CONCLUSION

We developed a selective, simple and inexpensive GC-MS method for parallel measurement of T and DHT with potential use in the clinical laboratory.

Potential humoral mediators of remote ischemic preconditioning in patients undergoing surgical coronary revascularization

Remote ischemic preconditioning (RIPC) by repeated brief cycles of limb ischemia/reperfusion may reduce myocardial ischemia/reperfusion injury and improve patients‘ prognosis after elective coronary artery bypass graft (CABG) surgery. The signal transducer and activator of transcription (STAT)5 activation in left ventricular myocardium is associated with RIPC´s cardioprotection. Cytokines and growth hormones typically activate STATs and could therefore act as humoral transfer factors of RIPC´s cardioprotection. We here determined arterial plasma concentrations of 25 different cytokines, growth hormones, and other factors which have previously been associated with cardioprotection, before (baseline)/after RIPC or placebo (n = 23/23), respectively, and before/after ischemic cardioplegic arrest in CABG patients. RIPC-induced protection was reflected by a 35% reduction of serum troponin I release. With the exception of interleukin-1α, none of the humoral factors changed in their concentrations after RIPC or placebo, respectively. Interleukin-1α, when normalized to baseline, increased after RIPC (280 ± 56%) but not with placebo (97 ± 15%). The interleukin-1α concentration remained increased until after ischemic cardioplegic arrest and was also higher than with placebo in absolute concentrations (25 ± 6 versus 16 ± 3 pg/mL). Only interleukin-1α possibly fulfills the criteria which would be expected from a substance to be released in response to RIPC and to protect the myocardium during ischemic cardioplegic arrest.

The steroid response to human chorionic gonadotropin (hCG) stimulation in men with Klinefelter syndrome does not change using immunoassay or mass spectrometry

PURPOSE

Liquid-chromatography tandem mass-spectrometry (LC-MS/MS) was developed in parallel to Immunoassays (IAs) and today is proposed as the "gold standard" for steroid assays. Leydig cells of men with Klinefelter syndrome (KS) are able to respond to human chorionic gonadotropin (hCG) stimulation, even if testosterone (T) production was impaired. The aim was to evaluate how results obtained by IAs and LC-MS/MS can differently impact on the outcome of a clinical research on gonadal steroidogenesis after hCG stimulation.

METHODS

A longitudinal, prospective, case-control clinical trial. (clinicaltrial.gov NCT02788136) was carried out, enrolling KS men and healthy age-matched controls, stimulated by hCG administration. Serum steroids were evaluated at baseline and for 5 days after intramuscular injection of 5000 IU hCG using both IAs and LC-MS/MS.

RESULTS

13 KS patients (36 ± 9 years) not receiving T replacement therapy and 14 controls (32 ± 8 years) were enrolled. T, progesterone, cortisol, 17-hydroxy-progesterone (17OHP) and androstenedione, were significantly higher using IAs than LC-MS/MS. IAs and LC-MS/MS showed direct correlation for all five steroids, although the constant overestimation detected by IAs. Either methodology found the same 17OHP and T increasing profile after hCG stimulation, with equal areas under the curves (AUCs).

CONCLUSIONS

Although a linearity between IA and LC-MS/MS is demonstrated, LC-MS/MS is more sensitive and accurate, whereas IA shows a constant overestimation of sex steroid levels. This result suggests the need of reference intervals built on the specific assay. This fundamental difference between these two methodologies opens a deep reconsideration of what is needed to improve the accuracy of steroid hormone assays.