Safety of standardised treatments for haematologic malignancies as regards to testicular endocrine function in children and teenagers

Assessment of testicular function in boys and adolescents

OBJECTIVE

The hypothalamic-pituitary-testicular axis is characterised by the existence of major functional changes from its establishment in fetal life until the end of puberty. The assessment of serum testosterone and gonadotrophins and semen analysis, typically used in the adult male, is not applicable during most of infancy and childhood. On the other hand, the disorders of gonadal axis have different clinical consequences depending on the developmental stage at which the dysfunction is established. This review addresses the approaches to evaluate the hypothalamic-pituitary-testicular axis in the newborn, during childhood and at pubertal age.

DESIGN

We focused on the hormonal laboratory and genetic studies as well as on the clinical signs and imaging studies that guide the aetiological diagnosis and the functional status of the gonads.

RESULTS

Serum gonadotrophin and testosterone determination is useful in the first 3-6 months after birth and at pubertal age, whereas AMH and inhibin B are useful biomarkers of testis function from birth until the end of puberty. Clinical and imaging signs are helpful to appraise testicular hormone actions during fetal and postnatal life.

CONCLUSIONS

The interpretation of results derived from the assessment of hypothalamic-pituitary-testicular in paediatric patients requires a comprehensive knowledge of the developmental physiology of the axis to understand its pathophysiology and reach an accurate diagnosis of its disorders.

Effect of Humanin and MOTS-c on ameliorating reproductive damage induced by prepubertal cyclophosphamide chemotherapy in male mice

Male patients who undergo prepubertal chemotherapy face the dual problems of fertility preservation in adulthood, including low testosterone, hypersexual function, and infertility. Humanin, as a small polypeptide coded within the mitochondrial DNA, with the mitochondrial short open reading frame named MOTS-c, both was believed to regulate mitochondrial homeostasis, be anti-inflammatory, improve metabolism, anti-apoptosis, and multiple pharmacological effects. However, there exists little evidence that reported Humanin and MOTS-c 's effects on moderating male spermatogenic function of patients after prepubertal chemotherapy. Here, we found that in vivo, mitochondrial polypeptides Humanin analog (HNG) and MOTS-c efficaciously protected the testicular spermatogenic function from reproductive injury. Moreover, transcriptomic sequencing analysis was performed to verify the differentially expressed genes such as Piwil2, AGT (angiotensinogen), and PTGDS (glycoprotein prostaglandin D2 synthase), which are related to the regulation of male reproductive function of male mice induced by prepubertal chemotherapy. Collectively, our data revealed that both Humanin analogs HNG and MOTS-c are the feasible approaches attached to the protective effect on the male reproductive function damaged by prepubertal chemotherapy.

Testicular dysfunction at diagnosis in children and teenagers with haematopoietic malignancies improves after initial chemotherapy

Introduction

Hematopoietic malignancies are the most frequent type of cancer in childhood. Recent advances in cancer treatment have significantly improved survival until adulthood. There is an extensive literature on the effects of cancer treatment on the gonadal axis in adult survivors of childhood cancer mainly focused on sperm production, but scarce information exists on the immediate impact of cancer and its treatment in boys.

Objectives

In this work, we determined the status of the hypothalamic-pituitary-testicular (HPT) axis function at diagnosis and the immediate impact of chemotherapy at the start of treatment in children and adolescents with hematopoietic malignancies.

Subjects and methods

In a prospective study of 94 boys and adolescents with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) or non-Hodgkin lymphoma (NHL), we determined serum AMH, inhibin B and FSH to assess the gonadotrophin-Sertoli cell component of the HPT axis, and testosterone and LH to evaluate the gonadotrophin-Leydig cell component, at diagnosis and after 3 months of chemotherapy. Secondarily, the general health state was evaluated.

Results

In prepubertal boys, at diagnosis, AMH, inhibin B and FSH were lower compared to the reference population, reflecting an FSH-Sertoli cell axis dysfunction. After 3 months of chemotherapy, all hormone concentrations increased. At pubertal age, at diagnosis, AMH and inhibin B were lower compared to the reference population for Tanner stage, with inappropriately normal FSH, suggesting a primary Sertoli cell dysfunction with insufficient gonadotrophin compensation. The LH-Leydig cell axis was mildly disrupted. After 3 months of chemotherapy, inhibin B and AMH were unchanged while median FSH levels rose to values that exceeded the reference range, indicating a significant impairment of Sertoli cell function. Testosterone normalized concomitantly with an abnormal LH elevation reflecting a compensated Leydig cell impairment. General health biomarkers were impaired at diagnosis and improved after 3 months.

Conclusion

The HPT axis function is impaired in boys with hematopoietic malignancies before the initiation of chemotherapy. There is a primary testicular dysfunction and a concomitant functional central hypogonadism that could be due to an impaired overall health. The HPT axis function improves during the initial 3 months of chemotherapy concomitantly with the general health state. However, in pubertal boys the dysfunction persists as shown by elevated gonadotropin levels after 3 months.

The Use of Biomarkers in Pharmacovigilance: A Systematic Review of the Literature

Background

The use of biomarkers varies from disease etiognosis and diagnosis to signal detection, risk prediction, and management. Biomarker use has expanded in recent years, however, there are limited reviews on the use of biomarkers in pharmacovigilance and specifically in the monitoring and management of adverse drug reactions (ADRs).

Objective

The objective of this manuscript is to identify the multiple uses of biomarkers in pharmacovigilance irrespective of the therapeutic area.

Design

This is a systematic review of the literature.

Data Sources and Methods

Embase and MEDLINE database searches were conducted for literature published between 2010-March 19, 2021. Scientific articles that described the potential use of biomarkers in pharmacovigilance in sufficient detail were reviewed. Papers that did not fulfill the United States Food and Drug Administration (US FDA) definition of a biomarker were excluded, which is based on the International Conference on Harmonisation (ICH)-E16 guidance.

Results

Twenty-seven articles were identified for evaluation. Most articles involved predictive biomarkers (41%), followed by safety biomarkers (38%), pharmacodynamic/response biomarkers (14%), and diagnostic biomarkers (7%). Some articles described biomarkers that applied to multiple categories.

Conclusion

Various categories of biomarkers including safety, predictive, pharmacodynamic/response, and diagnostic biomarkers are being investigated for potential use in pharmacovigilance. The most frequent potential uses of biomarkers in pharmacovigilance in the literature were the prediction of the severity of an ADR, mortality, response, safety, and toxicity. The safety biomarkers identified were used to evaluate patient safety during dose escalation, identify patients who may benefit from further biomarker testing during treatment, and monitor ADRs.

Review of the Function of the Hypothalamic-Pituitary-Gonadal Axis in Children and Adolescents with Cancer

The most common malignancies in childhood are leukaemias, brain tumours, lymphomas, neuroblastomas, soft tissue sarcomas and kidney tumours. At present, about 80% of childhood cancers can be treated successfully, which has significantly increased long-term survival. Concomitantly, adult gonadal function in childhood cancer survivors has become a concern. However, the immediate effect of cancer and its management on the reproductive axis function has received less attention. We conducted a review of the effects of malignancies and their treatments on the gonadal axis during childhood and adolescence. Some results are controversial, probably because the analyses do not distinguish between the malignancy types, their treatments and/or the age at treatment. However, there is agreement that cancer can partially affect gonadal function before treatment, as revealed by low circulating levels of inhibin B and anti-Müllerian hormone. Subsequently, chemotherapy transiently impairs the somatic component of the gonads (i.e. testicular Sertoli cells and ovarian granulosa cells) with normalization after treatment ends. The impact of chemotherapy may persist through adulthood after more intensive chemotherapy regimens, radiotherapy and conditioning for haematopoietic stem cell transplantation, when there is a severe impairment of the somatic component of the gonads or of the stem germ cells.

Considerations when treating male pubertal delay pharmacologically

INTRODUCTION

Delayed puberty, defined as the appearance of pubertal signs after the age of 14 years in males, usually affects psychosocial well-being. Patients and their parents show concern about genital development and stature. The condition is transient in most of the patients; nonetheless, the opportunity should not be missed to diagnose an underlying illness.

AREAS COVERED

The aetiologies of pubertal delay in males and their specific pharmacological therapies are discussed in this review.

EXPERT OPINION

High-quality evidence addressing the best pharmacological therapy approach for each aetiology of delayed puberty in males is scarce, and most of the current practice is based on small case series or unpublished experience. Male teenagers seeking attention for pubertal delay most probably benefit from medical treatment to avoid psychosocial distress. While watchful waiting is appropriate in 12- to 14-year-old boys when constitutional delay of growth and puberty (CGDP) is suspected, hormone replacement should not be delayed beyond the age of 14 years in order to avoid impairing height potential and peak bone mass. When primary or central hypogonadism is diagnosed, hormone replacement should be proposed by the age of 12 years provided that a functional central hypogonadism has been ruled out. Testosterone replacement regimens have been used for decades and are fairly standardised. Aromatase inhibitors have arisen as an interesting alternative for boy with CDGP and short stature. Gonadotrophin therapy seems more physiological in patients with central hypogonadism, but its relative efficacy and most adequate timing still need to be established.

Biomarcadores de hipogonadismo masculino en la infancia y la adolescencia

El eje hipotálamo-hipófiso-testicular es activo en la vida fetal y durante los primeros meses de la vida posnatal: la hipófisis secreta hormona luteinizante (LH) y folículo-estimulante (FSH), mientras que el testículo produce testosterona y factor insulino-símil 3 (INSL3) en las células de Leydig y hormona anti-Mülleriana (AMH) e inhibina B en las células de Sertoli. En la infancia, los niveles séricos de gonadotrofinas, testosterona y factor INSL3 disminuyen a valores prácticamente indetectables, pero los de AMH e inhibina B permanecen altos. En la pubertad, se reactivan las gonadotrofinas y la producción de testosterona e INSL3, aumenta la inhibina y disminuye la AMH, como signo de maduración de la célula de Sertoli. Sobre la base del conocimiento de la fisiología del desarrollo del eje, es posible utilizar clínicamente estos biomarcadores para interpretar la fisiopatología y diagnosticar las diferentes formas de hipogonadismo que pueden presentarse en la infancia y la adolescencia.

Biomarkers of male hypogonadism in childhood and adolescence

Objectives

The objective of this review was to characterize the use of biomarkers of male hypogonadism in childhood and adolescence.

Contents

The hypothalamic-pituitary-gonadal (HPG) axis is active during fetal life and over the first months of postnatal life. The pituitary gland secretes follicle stimulating hormone (FSH) and luteinizing hormone (LH), whereas the testes induce Leydig cells to produce testosterone and insulin-like factor 3 (INSL), and drive Sertoli cells to secrete anti-Müllerian hormone (AMH) and inhibin B. During childhood, serum levels of gonadotropins, testosterone and insulin-like 3 (INSL3) decline to undetectable levels, whereas levels of AMH and inhibin B remain high. During puberty, the production of gonadotropins, testosterone, and INSL3 is reactivated, inhibin B increases, and AMH decreases as a sign of Sertoli cell maturation.

Summary and outlook

Based on our knowledge of the developmental physiology of the HPG axis, these biomarkers can be used in clinical practice to interpret the physiopathology of hypogonadism. Additionally, these markers can have diagnostic value in different forms of hypogonadism that may appear during childhood and adolescence.