Random urinary gonadotropins as a useful initial test for girls with central precocious puberty

Comparative Analysis of Commercial Immunoassays for the Determination of Total, Intact, and Nonintact Luteinizing Hormone in Urine

BACKGROUND

In our recent publications, we reported the identification of three different molecular forms of total luteinizing hormone (LH) in urine, the intact LH, the free beta-subunit (LHβ), and its core fragment of LHβ (LHβcf), the latter two establishing the nonintact portion of LH. Following the discontinuation of the Delfia immunofluorometric assay (IFMA) (Wallac, PerkinElmer Finland, Finland), a leading method for detecting urinary LH for 30 years, this study seeks to assess the efficacy of three alternative commercial immunoassays in identifying various forms of U-LH.

METHODS

Diluted urine samples underwent gel filtration to separate them into fractions, each containing different forms of LH. These were then assayed using Delfia IFMA, Architect LH (Abbott, USA), Elecsys LH Cobas (Roche, Switzerland), and Immulite 2000 LH (Siemens, Germany) immunoassays.

RESULTS

Both Delfia and Immulite assays detected total U-LH, that is, all three forms of U-LH, including intact LH, LHβ, and LHβcf. Cobas detected only intact LH and LHβ, whereas Architect detected solely the intact LH.

CONCLUSIONS

Immulite assay can be an alternative tool to detect all forms of urinary LH, a feature likely to be instrumental in developing noninvasive, practical, and scalable solutions for evaluating total U-LH changes during minipuberty in neonates, during the onset of central puberty in peripubertal children, puberty-associated disorders in adolescents, and the fertility window in women, with a special focus on postpeak changes.

Urinary gonadotropin assay on 24-h collections as a tool to detect early central puberty onset in girls: determination of predictive thresholds

STUDY QUESTION

Is the 24-h urinary gonadotropin assay an effective diagnostic tool in central precocious puberty (CPP) in girls?

SUMMARY ANSWER

This study is the first to provide 24-h urinary gonadotropin assay data, using an electrochemiluminescent immunoassay (CMIA), and to report its usefulness as a tool for the diagnosis of CPP.

WHAT IS KNOWN ALREADY

Data about the GnRH test in the diagnosis of CPP are variable and there is no consensus regarding its interpretation. The measurement of FSH and LH in urines was previously reported to be an alternative biological tool.

STUDY DESIGN, SIZE, DURATION

This is a retrospective two-cohort study, involving a setting and a validation cohort. A total of 516 girls, included between October 2012 and July 2015, and 632 urinary collections were analyzed in the setting cohort. In the validation cohort, 39 girls were included between January 2021 and May 2023, and 49 urinary collections were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study included girls who consulted for an investigation of disturbed growth rate or a clinical suspicion of puberty onset in different medical centres across France (setting cohort). Girls with a suspicion of precocious puberty onset were addressed at the expert centre of paediatric endocrinology of the Groupement Hospitalier Lyon Est (validation cohort). Pelvic ultrasonography was performed and enabled their classification according to clinical and morphologic changes criteria (prepubertal or pubertal groups). The parents collected 24-h urine samples (u24) according to standardized instructions. FSH and LH (urinary or plasmatic) were measured using a current and automated CMIA.

MAIN RESULTS AND THE ROLE OF CHANCE

The area under the ROC curves for CPP prediction was 0.709 for u24FSH (P < 0.001), 0.767 for u24LH (P < 0.001), and 0.753 for the u24LH/u24FSH ratio (P < 0.001). We retained all possible combinations of the four thresholds in the validation cohort (u24FSH = 1.1 or 2.0 IU/24 h; u24LH = 0.035 or 0.08 IU/24 h). The combination of u24FSH > 1.1 IU/24 h and u24LH > 0.08 IU/24 h had a positive PV of 85.7% and a negative PV of 94.3%, a sensitivity of 85.7% and a specificity of 94.3%, for classifying prepubertal and pubertal girls in this cohort.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study, in which a margin of error remains due to the inherent uncertainty regarding the clinical assessment of pubertal onset. It must be considered that the thresholds can only apply to the used reagents; measurements without extractions using other reagents are likely to show important heterogeneity.

WIDER IMPLICATIONS OF THE FINDINGS

The assay performed herein is a simple, non-invasive, and analytically robust technique meeting the criteria for an alternative to the GnRH test which could be used to supplement its lack of sensitivity.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was used. All authors declared no conflict of interest.

TRIAL REGISTRATION NUMBER

In-house #23-5214 registered study.

The negative impact of levothyroxine treatment on urinary luteinizing hormone measurements in pediatric patients with thyroid disease

Objectives

Previous studies suggest urinary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) measurements by immunofluorometric assays (IFMA) as noninvasive alternatives to serum assays for puberty assessment. However, these studies excluded patients with other endocrine disorders and those taking medications. Besides, the recent discontinuation of IFMA manufacturing is a concern. We explored the utility of luminometric assays (LIA) for urinary gonadotropins and thyroid-stimulating hormone (TSH) determinations in euthyroid patients with thyroid pathologies.

Methods

We used LIA and IFMA assays to measure serum and first-morning-voided (FMV) urine LH, FSH, and TSH concentrations in euthyroid patients with various thyroid disorders. Of the 47 euthyroid patients with normal serum TSH (S-TSH) levels, 14 were receiving levothyroxine therapy.

Results

FMV total urinary LH (U-LH) concentrations correlated significantly with those measured in serum using either LIA (r=0.67, P<.001) or IFMA (r=0.83, P=.003) in patients not receiving levothyroxine treatment; however, no significant correlation could be detected in patients receiving levothyroxine regardless of the assay method (for LIA: r=0.50, P=.08 and IFMA r=0.44, P=.15). Urinary TSH (U-TSH) concentrations correlated poorly with those in serum in both the untreated and the treated groups (r=-0.13, P=.49, and r=-0.45, P=.11, respectively).

Conclusion

FMV total U-LH determinations by LIA can be used to assess pubertal development in patients with thyroid pathology, provided the euthyroid patient is not on levothyroxine treatment. U-TSH measurements by LIA cannot replace invasive S-TSH measurements at least in patients with normal S-TSH levels. Further research may reveal the utility of U-TSH determinations in patients with elevated S-TSH levels.

Urine Sampling Protocol Recommendations for Reliable Determination of Total Urinary Luteinizing Hormone Immunoreactivity in the Pediatric Population

This study investigates day-to-day variations in urinary luteinizing hormone (U-LH) concentrations in children, focusing on potential minimization or correction methods. 95 children and adolescents (51 boys, 44 girls, ages 5-17) provided daytime and evening urine samples for U-LH determinations over three consecutive days. No consistent day-to-day differences in U-LH levels were observed, although random variations, particularly in adolescents aged 13 or older, were noted. The net inter-assay CV% for U-LH changes over three days showed high variability, averaging 24.6% to 28.0% for boys and 21.6% to 27.3% for girls, independent of sex, collection time, or U-LH level. To reliably determine total urinary luteinizing hormone immunoreactivity in the pediatric population, it is advisable to collect multiple first-morning voided samples for at least three consecutive days as an interim solution, pending the development of a standardized protocol or correction method for varying urine composition. Strict adherence, especially for adolescents aged 13 or older, is vital.

Follistatin-like 1 and its paralogs in heart development and cardiovascular disease

Cardiovascular diseases (CVDs) are a group of disorders affecting the heart and blood vessels and a leading cause of death worldwide. Thus, there is a need to identify new cardiokines that may protect the heart from damage as reported in GBD 2017 Causes of Death Collaborators (2018) (The Lancet 392:1736-1788). Follistatin-like 1 (FSTL1) is a cardiokine that is highly expressed in the heart and released to the serum after cardiac injury where it is associated with CVD and predicts poor outcome. The action of FSTL1 likely depends not only on the tissue source but also post-translation modifications that are target tissue- and cell-specific. Animal studies examining the effect of FSTL1 in various models of heart disease have exploded over the past 15 years and primarily report a protective effect spanning from inhibiting inflammation via transforming growth factor, preventing remodeling and fibrosis to promoting angiogenesis and hypertrophy. A better understanding of FSTL1 and its homologs is needed to determine whether this protein could be a useful novel biomarker to predict poor outcome and death and whether it has therapeutic potential. The aim of this review is to provide a comprehensive description of the literature for this family of proteins in order to better understand their role in normal physiology and CVD.

The value of urinary gonadotropins in the diagnosis of central precocious puberty: a meta-analysis

BACKGROUND

The gonadotropin-releasing hormone (GnRH) stimulation test is time-consuming, invasive, and costly. However, it is the diagnostic gold standard for central precocious puberty (CPP), which in girls is defined as the onset of secondary sexual characteristics before the age of 8 years accompanied by breast buds, accelerated growth, and advanced bone age. This meta-analysis was performed to compare the diagnostic value of urinary gonadotropins and the GnRH stimulation test for CPP.

METHODS

We searched six databases for relevant literature. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we estimated the sensitivity, specificity, area under the summary receiver operating characteristic curve (AUC), and publication bias.

RESULTS

Six eligible trials fulfilled the inclusion criteria. In the meta-analysis of urinary luteinizing hormone (ULH), after excluding the data of one study, we obtained an AUC of 0.90 (sensitivity = 0.81, specificity = 0.85). The meta-analysis of the ULH to urinary follicle-stimulating hormone (UFSH) ratio revealed an AUC of 0.8116 (sensitivity = 0.79, specificity = 0.84).

CONCLUSION

Both the ULH level and ULH:UFSH ratio are effective and available approaches for CPP diagnosis.

TRIAL REGISTRATION

INPLASY 2021120076 .

First morning voided urinary gonadotropins in children: verification of method performance and establishment of reference intervals

OBJECTIVES

Urinary luteinizing hormone (uLH) and urinary follicle-stimulating hormone (uFSH) have been shown to be useful screening and management tools for children with central precocious puberty. However, studies on uLH and uFSH reference intervals are scarce. Therefore, we aimed to establish reference intervals for uLH and uFSH, according to age, sex, and pubertal status in apparently healthy children aged 6-11 years.

METHODS

We performed detection capability, precision, accuracy by recovery, linearity, agreement analysis, and stability testing to analyze the method performance of uLH and uFSH. The Clinical Laboratory Standards Institute's C28-A3 criteria was used to establish the reference intervals.

RESULTS

Both uLH and uFSH were stable at 4 °C for 52.6 h and 64.8 days, respectively. The total imprecision of uFSH is within the manufacturer's claim, while the total imprecision of uLH remained within tolerable bias. Both uLH and uFSH could be measured with acceptable detection capability. The recovery rates of the hormones were 87.6-98.8% and 102.8-103.4%, respectively, and therefore within acceptable limits. There were significant correlations between the serum and urine concentrations (LH: r=0.91, p<0.001; FSH: r=0.90, p<0.001). The reference intervals of uLH and uFSH were established according to age, sex, and pubertal status.

CONCLUSIONS

We established reference intervals for uLH and uFSH based on age, sex and pubertal status to provide a non-invasive clinical screening tool for precocious puberty in children aged 6-11 years.

Reproducibility and Refinement of Urinary LH in the Screening of Progressive Puberty in Girls

CONTEXT

First-voided urinary LH (FVU-LH) has been suggested as an alternative to GnRH stimulation test for detection of precocious puberty.

OBJECTIVE

To evaluate the reproducibility of FVU-LH, its correlation with basal and GnRH-stimulated gonadotropins, and its diagnostic value for differentiating progressive from nonprogressive puberty.

DESIGN AND PARTICIPANTS

Clinical and endocrine data were obtained from the medical records of 95 girls with suspected progressive puberty who underwent 2 consecutive FVU-LH tests. In 55 of these participants, GnRH stimulation test was performed close to the FVU-LH test. The reported cutoff levels of 5 IU/L and 1.16 IU/L for GnRH-stimulated LH and FVU-LH, respectively, were used as markers of progressive puberty, clinically defined as bone age advancement of ≥1 year and/or growth velocity SD score ≥2, in addition to thelarche.

RESULTS

The 2 consecutive measurements of FVU-LH were highly correlated (r = 0.830; P < 0.001). The higher of the 2 results was better correlated with basal gonadotropins and GnRH-stimulated LH. Furthermore, it aligned better with the clinical outcome of girls with early thelarche, which supports the approach of double tests of FVU-LH to distinguish progressive from nonprogressive puberty. By comparison to GnRH-stimulated LH, the higher FVU-LH value had better sensitivity (68%), whereas peak LH had better specificity (91%) for the diagnosis of progressive puberty. Both tests had high positive predictive value and poor negative predictive value.

CONCLUSIONS

The higher value of paired FVU-LH tests can be used to screen girls with suspected progressive puberty and can reduce the need for GnRH stimulation test.

The Use of Morning Urinary Gonadotropins and Sex Hormones in the Management of Early Puberty in Chinese Girls

CONTEXT

Although gonadotropin-releasing hormone stimulation test (GnRHST) is the gold standard in diagnosing central precocious puberty (CPP), it is invasive, expensive, and time-consuming, requiring multiple blood samples to measure gonadotropin levels.

OBJECTIVE

We evaluated whether urinary hormones could be potential biomarkers for prepuberty or postpuberty, aiming to simplify the current diagnosis and prognosis procedure.

METHODS

We performed a cross-sectional study of a total of 355 girls with CPP in National Clinical Research Center for Child Health in China, including 258 girls with positive and 97 girls with negative results from GnRHST. Twenty patients received GnRH analogue (GnRHa) treatment and completed a 6-month follow up. We measured luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, prolactin, progesterone, testosterone, and human chorionic gonadotropin in the first morning voided urine samples.

RESULTS

Their urinary LH levels and the ratios of LH to FSH increased significantly with the advancement in Tanner stages. uLH levels were positively associated with basal and peak LH levels in the serum after GnRH stimulation. A cutoff value of 1.74 IU/L for uLH reached a sensitivity of 69.4% and a specificity of 75.3% in predicting a positive GnRHST result. For the combined threshold (uLH ≥ 1.74 + uLH-to-uFSH ratio > 0.4), the specificity reached 86.6%. After 3 months of GnRHa therapy, the uLH and uFSH levels decreased accordingly.

CONCLUSION

uLH could be a reliable biomarker for initial CPP diagnosis and screening; uLH could also be an effective marker for evaluating the efficacy of clinical treatment.

Urinary gonadotropin measurements by enhanced luminometric assays (LIA) for the evaluation of pubertal development

OBJECTIVES

Determination of LH in urine has proved to be a reliable method for evaluation of pubertal development. The human LH assay based on time-resolved immunofluorometric (IFMA) technology (AutoDELFIA, PerkinElmer, Wallac) has been found to be suitable for this purpose thanks to its high sensitivity but other assays have not been evaluated. We have analyzed our data obtained by another potentially sensitive detection technique, enhanced luminometric assay (LIA) with the objective of finding a viable alternative to IFMA since these may not be available in the future.

METHODS

LIA was used to measure LH and FSH in serum and urine samples from 100 healthy subjects of each Tanner stage and both genders, whose pubertal development has been determined.

RESULTS

Urinary gonodotropin concentrations measured by LIA correlated well with Tanner stage [(r=0.93 for girls, r=0.81 for boys; p<0.01 for LH) and (r=0.81 for girls, r=0.73 for boys; p<0.01 for FSH)]. LIA determinations revealed the increase in U-LH concentrations during the transition from Tanner stage 1-2 in both girls and boys (p<0.001), whereas U-FSH and S-LH were able to detect the increase from Tanner stage 1-2 only in boys or girls, respectively (both p<0.001).

CONCLUSIONS

Measurement of urinary gonadotropin concentrations by LIA may be useful for the evaluation of overall pubertal development and also in the detection of transition from prepuberty to puberty.

Precocious puberty

Precocious puberty (PP) is a common reason for referral to pediatric endocrinology clinics, with a strong female predominance. PP is a broad term encompassing benign variants of normal development, gonadotropin-dependent precious puberty (GDPP), and gonadotropin-independent precocious puberty (GIPP). This article reviews the definitions, physiology, clinical presentation, evaluation and treatment of these conditions.