Utility of single luteinizing hormone determination 3 h after depot leuprolide in monitoring therapy of gonadotropin-dependent precocious puberty

Precocious Puberty: Types, Pathogenesis and Updated Management

Precocious puberty (PP) means the appearance of secondary sexual characters before the age of eight years in girls and nine years in boys. Puberty is indicated in girls by the enlargement of the breasts (thelarche) in girls and in boys by the enlargement of the testes in either volume or length (testicular volume = 4 mL, testicular length = 25 mm, or both). Two types of PP are recognized - namely central PP (CPP) and peripheral PP (PPP). This paper aims to describe the clinical findings and laboratory workup of PP and to illustrate the new trends in the management of precocious sexual maturation. Gonadotropin-releasing hormone (GnRH)-independent type (PPP) refers to the development of early pubertal maturation not related to the central activation of the hypothalamic-pituitary-gonadal (HPG) axis. It is classified into genetic or acquired disorders. The most common forms of congenital or genetic causes involve McCune-Albright syndrome (MAS), familial male-limited PP, and congenital adrenal hyperplasia. The acquired causes include exogenous exposure to androgens, functioning tumors or cysts, and the pseudo-PP of profound primary hypothyroidism. On the other hand, CPP is the most common and it is a gonadotropin-dependent form. It is due to premature maturation of the HPG axis. CPP may occur as genetic alterations, such as MKRN3, DLK1, or KISS1;as a part of mutations in the epigenetic factors that regulate the HPG axis, such as Lin28b and let-7; or as a part of syndromes, central lesions such as hypothalamic hamartoma, and others. A full, detailed history and physical examination should be taken. Furthermore, several investigations should be conducted for both types of PP, including the estimation of serum gonadotropins such as luteinizing and follicle-stimulating hormones and sex steroids, in addition to a radiographic workup and thyroid function tests. Treatment depends on the type of PP: Long-acting GnRHa, either intramuscularly or implanted, is the norm of care for CPP management, while in PPP, especially in congenital adrenal hyperplasia, the goal of management is to suppress adrenal androgen secretion by glucocorticoids. In addition, anastrozole and letrozole - third-generation aromatase inhibitors - are more potent for MAS.

Diagnosis and management of precocious sexual maturation: an updated review

The classic definition of precocious sexual maturation is the development of secondary sexual characteristics before 8 years of age in girls and before 9 years of age in boys. It is classified as central precocious puberty when premature maturation of the hypothalamic-pituitary-gonadal axis occurs, and as peripheral precocious puberty when there is excessive secretion of sex hormones, independent of gonadotropin secretion. Precocious sexual maturation is more common in girls, generally central precocious puberty of idiopathic origin. In boys, it tends to be linked to central nervous system abnormalities. Clinical evaluation should include a detailed history and physical examination, including anthropometric measurements, calculation of growth velocity, and evaluation of secondary sexual characteristics. The main sign to suspect the onset of puberty is breast tissue development (thelarche) in girls and testicular enlargement (≥4 mL) in boys. Hormonal assessment and imaging are required for diagnosis and identification of the etiology. Genetic testing should be considered if there is a family history of precocious puberty or other clinical features suggestive of a genetic syndrome. Long-acting gonadotropin-releasing hormone analogs are the standard of care for central precocious puberty management, while peripheral precocious puberty management depends on the etiology.Conclusion: The aim of this review is to address the epidemiology, etiology, clinical assessment, and management of precocious sexual maturation. What is Known: • The main sign to suspect the onset of puberty is breast tissue development (thelarche) in girls and testicular enlargement (≥4 mL) in boys. The classic definition of precocious sexual maturation is the development of secondary sexual characteristics before 8 years of age in girls and before 9 years of age in boys. • Long-acting gonadotropin-releasing hormone agonist (GnRHa) is the standard of care for CPP management, and adequate hormone suppression results in the stabilization of pubertal progression, a decline in growth velocity, and a decrease in bone age advancement. What is New: • Most cases of precocious sexual maturation are gonadotropin-dependent and currently assumed to be idiopathic, but mutations in genes involved in pubertal development have been identified, such as MKRN3 and DLK1. • A different preparation of long-acting GnRHa is now available: 6-month subcutaneous injection.

Gonadotropin and Estradiol Levels after Leuprolide Stimulation Tests in Brazilian Girls with Precocious Puberty

STUDY OBJECTIVE

To determine the best cutoff value on the leuprolide stimulation test for the diagnosis of central precocious puberty (CPP) in a Brazilian population.

DESIGN, SETTING, AND PARTICIPANTS

This observational study included 60 girls with CPP, as shown on the basis of serum concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) before and 3 hours after subcutaneous administration of 500 μg leuprolide acetate and by measuring serum estradiol concentrations 24 hours later. Six months later, each subject was clinically evaluated to determine whether she had experienced progressive or nonprogressive puberty.

MAIN OUTCOME MEASURES

Analyzing the best cutoff for LH after subcutaneous administration of 500 μg leuprolide acetate.

RESULTS

The best cutoff was a 3-hour LH level of greater than 4.0 mIU/mL, providing the highest sensitivity (73%) and specificity (83.1%), whereas a 3-hour LH level greater than 8.4 mIU/mL had a specificity of 100%. A 24-hour E2 concentration greater than 52.9 pg/mL had a sensitivity of 68% and a specificity of 74%. There was no association between pubertal development and disease progression. Signs such as thelarche and pubarche did not determine the evolution of the disease (P = .17). Clinical condition was associated with bone age/chronological age (P = .01), basal LH (P < .01), 3-hour LH (P = .02), baseline LH/FSH indices (P < .01) and after 3 hours (P < .01), and E2 at 24 hours (P = .02).

CONCLUSION

The optimal parameter indicating hypothalamic-pituitary-gonadal axis activation in our sample was a 3-hour LH level greater than 4.0 mIU/mL. A diagnosis of CPP, however, should be based on a set of criteria and not on an isolated measurement, because typical laboratory findings associated with CPP may not be present in all patients.

Challenges and controversies in diagnosis and management of gonadotropin dependent precocious puberty: An Indian perspective

Managing precocious puberty (PP) has been a challenge due to lack of standardized definition, gonadotrophins assay, gonadotrophin stimulation, timings for blood sampling, and parameters for assessing outcomes. This review evaluated available literature to simplify the algorithm for managing gonadotrophin dependent/central PP (CPP), with an Indian perspective. CPP is one of the commonest forms of PP and mimics the normal course of puberty, at an age <8 and 9 years for girls and boys respectively. Basal and post gonadotrophin hormone releasing hormone analog (GnRHa) luteinizing hormone (LH) ≥0.3-0.6 IU/L and ≥4-5 IU/L (30-60 min after GnRH/GnRHa administration) respectively, using modern ultrasensitive automated chemiluminescence assays, can be considered positive for central puberty initiation. Uterine length of >3.5 cm and uterine volume of >1.8 ml are two most specific indicators for true CPP. Therapy is indicated in children with CPP with accelerated bone age, height advancement, or psychosocial stress. Treatment goal is to halt puberty progression to a socially acceptable age, allowing the child to attain optimal height potential. GnRHa is the treatment of choice, with best height outcomes when initiated <6 years age. Treatment is recommended till 11 years age. LH suppression to <3 U/L may be a reasonable target in patients on GnRHa therapy. Medroxyprogesterone acetate holds an important place in managing PP in India, cause of high costs associated with GnRHa therapy. There is an urgent need for clinical trials from India, for establishing Indian cut-off for diagnosis, treatment and follow-up of children with PP.

Random luteinizing hormone often remains pubertal in children treated with the histrelin implant for central precocious puberty

OBJECTIVE

To investigate the use of random ultrasensitive (US) luteinizing hormone (LH) levels to monitor children being treated with a histrelin implant for central precocious puberty (CPP).

STUDY DESIGN

This was a prospective, uncontrolled, observational study at a pediatric endocrinology tertiary center. Thirty-three children (26 girls; mean age 7.2 ± 2.5 years) treated with a histrelin implant for CPP were enrolled. A random US LH measurement was obtained at 6 months, and a gonadotropin-releasing hormone analog stimulation test was performed at 12 months. Clinic visits occurred at baseline and at 6-month intervals.

RESULTS

In 59% of the patients (17 of 29), the 6-month random US LH exceeded the prepubertal range of ≤0.3 IU/L. In contrast, gonadotropin-releasing hormone analog stimulation tests revealed complete hypothalamic-pituitary-gonadal axis suppression (peak LH <4 IU/L) in all 31 patients who underwent testing. US LH levels were highly correlated with peak stimulated LH levels. The mean peak stimulated LH level was higher in patients with a pubertal random LH than in those with a prepubertal random LH (1.2 ± 0.5 IU/L vs 0.5 ± 0.1 IU/L; P < .01). No patient had clinical evidence of pubertal progression.

CONCLUSION

The random US LH level does not revert to a prepubertal range in more than one-half of patients with a histrelin implant and documented hypothalamic-pituitary-gonadal axis suppression. Long-term studies are needed to elucidate the optimal strategy for monitoring treatment in children with CPP.

Pharmacodynamics of aqueous leuprolide acetate stimulation testing in girls: correlation between clinical diagnosis and time of peak luteinizing hormone level

We assessed the pharmacodynamics of a 3-hour leuprolide stimulation test in 11 girls with precocious puberty to determine an optimal single sampling time. Luteinizing hormone level following leuprolide stimulation was near maximum by 30 minutes in girls with central precocious puberty, whereas it continued to rise slowly in girls with nonprogressive puberty.

Evaluation of GnRH analogue testing in diagnosis and management of children with pubertal disorders

CONTEXT

Gonadotrophin releasing hormone (GnRH) stimulation test is pivotal in the assessment of children with pubertal disorders. However, lack of availability and high cost often result in the test falling into disfavor. We routinely use the GnRH analogue stimulation test as an alternative at our center.

AIM

To present the data on children with endocrine disorders who underwent GnRH agonist stimulation test in pediatric endocrine clinic of a tertiary care referral hospital.

SETTING AND DESIGN

Pediatric endocrine clinic of a tertiary care referral hospital. Retrospective analysis of case records.

MATERIALS AND METHODS

The details pertaining to clinical and radiological parameters and hormonal tests were retrieved from case records of 15 children who underwent GnRH agonist stimulation test from May 2010 to April 2011.

RESULTS

Indications for testing with GnRH analogue were evaluation of delayed puberty, diagnosis of precocious puberty, assessment of hormonal suppression in treatment of precocious puberty and micropenis in two, nine, three and one cases, respectively. The results of the test and clinical and radiological parameters were in concordance. The test was also crucial in diagnosing the onset of central precocious puberty in two children with congenital adrenal hyperplasia.

CONCLUSION

GnRH agonist test is a convenient, safe test that can be performed on an out-patient basis and can help the clinicians in the correct diagnosis and appropriate treatment of various puberty-related disorders.

Assessment of gonadotrophin suppression in girls treated with GnRH analogue for central precocious puberty; validity of single luteinizing hormone measurement after leuprolide acetate injection

OBJECTIVE

Intravenous GnRH stimulation test has often been used as gold standard test for the evaluation of hypothalamic-pituitary-gonadal axis in the diagnosis of central precocious puberty (CPP) and in the assessment of pubertal suppression. However, this test is time-consuming, costly and uncomfortable for the patients. We aimed to analyse the validity of single LH sample 90 min after GnRH analogue (GnRHa) administration in the evaluation of gonadotrophin suppression during CPP therapy and to determine a cut-off level for LH indicating adequate suppression.

DESIGN

Prospective study.

PATIENTS AND METHODS

One hundred and forty-two patients with CPP were included in this study. Peak LH level during iv GnRH stimulation test after the third dose of GnRHa was compared with LH level 90 min after injection of the 3rd dose of GnRHa.

RESULTS

There was a positive correlation between LH level following a GnRHa injection and peak LH during standard iv GnRH stimulation test (r = 0·83; P < 0·0001). A LH value of 2·5 mIU/ml or less 90 min after GnRHa injection was considered to be the cut-off for the determination of pubertal suppression (sensitivity and specificity was 100% and 88%, respectively). In 117 patients, gonadotrophin suppression was existed according to both GnRHa and iv GnRH tests. In 25 patients, gonadotrophin suppression was not found in the GnRHa test. However, 16 of them were suppressed according to the iv GnRH test.

CONCLUSION

Single LH determination 90 min after GnRHa administration using a cut-off level of 2·5 mIU/ml reflects pubertal suppression with a high sensitivity and specificity. However, this test may fail to show pubertal suppression in some cases. Those patients who appear to be inadequately suppressed should be reassessed using standard iv GnRH stimulation test for optimal dose adjustment.