Anti-Müllerian Hormone and Testicular Function in Prepubertal Boys With Cryptorchidism

Cryptorchidism and puberty

Cryptorchidism is the condition in which one or both testes have not descended adequately into the scrotum. The congenital form of cryptorchidism is one of the most prevalent urogenital anomalies in male newborns. In the acquired form of cryptorchidism, the testis that was previously descended normally is no longer located in the scrotum. Cryptorchidism is associated with an increased risk of infertility and testicular germ cell tumors. However, data on pubertal progression are less well-established because of the limited number of studies. Here, we aim to review the currently available data on pubertal development in boys with a history of non-syndromic cryptorchidism-both congenital and acquired cryptorchidism. The review is focused on the timing of puberty, physical changes, testicular growth, and endocrine development during puberty. The available evidence demonstrated that the timing of the onset of puberty in boys with a history of congenital cryptorchidism does not differ from that of non-cryptorchid boys. Hypothalamic-pituitary-gonadal hormone measurements showed an impaired function or fewer Sertoli cells and/or germ cells among boys with a history of cryptorchidism, particularly with a history of bilateral cryptorchidism treated with orchiopexy. Leydig cell function is generally not affected in boys with a history of cryptorchidism. Data on pubertal development among boys with acquired cryptorchidism are lacking; therefore, more research is needed to investigate pubertal progression among such boys.

Anti-Müllerian hormone, testicular descent and cryptorchidism

Anti-Müllerian hormone (AMH) is a Sertoli cell-secreted glycoprotein involved in male fetal sex differentiation: it provokes the regression of Müllerian ducts, which otherwise give rise to the Fallopian tubes, the uterus and the upper part of the vagina. In the first trimester of fetal life, AMH is expressed independently of gonadotropins, whereas from the second trimester onwards AMH testicular production is stimulated by FSH and oestrogens; at puberty, AMH expression is inhibited by androgens. AMH has also been suggested to participate in testicular descent during fetal life, but its role remains unclear. Serum AMH is a well-recognized biomarker of testicular function from birth to the first stages of puberty. Especially in boys with nonpalpable gonads, serum AMH is the most useful marker of the existence of testicular tissue. In boys with cryptorchidism, serum AMH levels reflect the mass of functional Sertoli cells: they are lower in patients with bilateral than in those with unilateral cryptorchidism. Interestingly, serum AMH increases after testis relocation to the scrotum, suggesting that the ectopic position result in testicular dysfunction, which may be at least partially reversible. In boys with cryptorchidism associated with micropenis, low AMH and FSH are indicative of central hypogonadism, and serum AMH is a good marker of effective FSH treatment. In patients with cryptorchidism in the context of disorders of sex development, low serum AMH is suggestive of gonadal dysgenesis, whereas normal or high AMH is found in patients with isolated androgen synthesis defects or with androgen insensitivity. In syndromic disorders, assessment of serum AMH has shown that Sertoli cell function is preserved in boys with Klinefelter syndrome until mid-puberty, while it is affected in patients with Noonan, Prader-Willi or Down syndromes.

A massive alteration of gene expression in undescended testicles of dogs and the association of KAT6A variants with cryptorchidism

Cryptorchidism is the most common form of disorder of sex development in male dogs, but its hereditary predisposition is poorly elucidated. The gonadal transcriptome of nine unilaterally cryptorchid dogs and seven control dogs was analyzed using RNA-seq. Comparison between the scrotal and inguinal gonads of unilateral cryptorchid dogs revealed 8,028 differentially expressed genes (DEGs) (3,377 up-regulated and 4,651 down-regulated). A similar number of DEGs (7,619) was found by comparing the undescended testicles with the descended testicles of the control dogs. The methylation status of the selected DEGs was also analyzed, with three out of nine studied DEGs showing altered patterns. Bioinformatic analysis of the cDNA sequences revealed 20,366 SNP variants, six of which showed significant differences in allelic counts between cryptorchid and control dogs. Validation studies in larger cohorts of cryptorchid (n = 122) and control (n = 173) dogs showed that the TT genotype (rs850666472, p.Ala1230Val) and the AA genotype in 3'UTR (16:23716202G>A) in KATA6, responsible for acetylation of lysine 9 in histone H3, are associated with cryptorchidism (P = 0.0383). Both the transcript level of KAT6A and H3K9 acetylation were lower in undescended testes, and additionally, the acetylation depended on the genotypes in exon 17 and the 3'UTR. Our study showed that the massive alteration of the transcriptome in undescended testicles is not caused by germinal DNA variants in DEG regulatory sequences but is partly associated with an aberrant DNA methylation and H3K9 acetylation patterns. Moreover, variants of KAT6A can be considered markers associated with the risk of this disorder.

CAG and GGN repeat polymorphisms in the androgen receptor gene of a Chilean pediatric cohort with idiopathic inguinal cryptorchidism

BACKGROUND

Cryptorchidism is one of the most common congenital disorders in boys and it is associated with a higher risk of sub-fertility and testicular cancer. Testicular descent occurs during embryo-fetal development in two phases, transabdominal and inguino-scrotal. In the latter process, androgens play a leading role. The androgen receptor has in its N-terminal domain, two aminoacidic repeats encoded by polymorphic nucleotide repetitions: (CAG)nCAA and GGN. The number of repetitions of these trinucleotides has been associated with different transactivation capacities and sensitivities of the androgen receptor response.

OBJECTIVE

To determine whether pediatric Chilean individuals with idiopathic inguinal cryptorchidism have a different number of CAG and/or GGN repeats polymorphisms compared with controls.

MATERIALS AND METHODS

A total of 109 cases with idiopathic inguinal cryptorchidism (26 bilateral and 83 unilateral) were studied by polymerase chain reaction amplification from DNA extracted from peripheral blood, followed by fragment size analysis by capillary electrophoresis, which were compared with 140 controls.

RESULTS

The CAG26 repeats allele was increased in the total cases (8.3% vs. 1.4%; p = 0.012; odds ratio = 6.21, 95% confidence interval 1.31-29.4), and in bilateral cases compared to controls (11.5% vs. 1.4%; p = 0.028; odds ratio = 9 CI 95% 1.43-56.8). Similarly, CAG > 22 alleles were increased in the total cases (62.4% vs. 49.3%, p = 0.041), and more significantly in bilateral cases (73.1% vs. 49.3%; p = 0.032; odds ratio = 2.79, 95% confidence interval 1.1-7.1). In addition, CAG < 18 alleles were not observed among cases, but were present in 5.7% of controls (p = 0.01). Regarding the GGN repeats, no differences were observed between cases and controls either when analyzing separately unilateral and bilateral cryptorchidism. The joint analysis of the distribution of CAG and GGN alleles showed that the CAG26 allele was present with GGN23, hence the combination CAG26/GGN23 alleles was equally increased in bilateral cases compared with controls (11.5% vs. 1.4%). In contrast, CAG < 18 was preferably observed in the combination CAG < 18/GGN≠23 and was absent in the total cases (4.3% vs. 0%; p = 0.037).

DISCUSSION

These results suggest that greater lengths of CAG alleles may contribute to a diminished androgen receptor function. The CAG26 allele alone or in combination with GGN23 was associated with a higher risk of bilateral cryptorchidism. On the other hand, CAG < 18 and the CAG < 18/GGN≠23 allele combination may reduce the probability of cryptorchidism.

Gonadal Function in Boys with Bilateral Undescended Testes

Background

Bilateral undescended testes (BUDT) may be a marker of an underlying condition that affects sex development or maturation.

Aims

To describe the extent of gonadal dysfunction in cases of BUDT who had systematic endocrine and genetic evaluation at a single tertiary pediatric center.

Methods

A retrospective review was conducted of all boys with BUDT who had endocrine evaluation between 2008 and 2021 at the Royal Hospital for Children, Glasgow (RHCG). Continuous variables were analyzed using Mann-Whitney U and non-continuous variables using Fisher's exact, via Graphpad Prism v 8.0. Multivariable logistic regression was used to identify any associations between groups. A P < .05 was considered statistically significant.

Results

A total of 243 bilateral orchidopexies were performed at RHCG between 2008 and 2021. Of these 130 (53%) boys were seen by the endocrine team. The median (range) age at first orchidopexy was 1 year (0.2, 18.0) with 16 (12%) requiring re-do orchidopexy. The median External Masculinization Score of the group was 10 (2, 11) with 33 (25%) having additional genital features. Of the 130 boys, 71 (55%) had extragenital anomalies. Of the 70 who were tested, a genetic abnormality was detected in 38 (54%), most commonly a chromosomal variant in 16 (40%). Of the 100 who were tested, endocrine dysfunction was identified in 38 (38%).

Conclusion

Genetic findings and evidence of gonadal dysfunction are common in boys who are investigated secondary to presentation with BUDT. Endocrine and genetic evaluation should be part of routine clinical management of all cases of BUDT.

[Hormonal and genetic causes of cryptorchidism]

Cryptorchidism is the most frequent congenital disorders of the reproductive system, is present in 2-3% of term newborn boys. Genes involved in embryonic testicular migration are known but their role in cryptorchidism development are not investigated enough. Genetical causes of cryptorchidism are identified in 5-7% of patients. The article contains data on the role of insulin-like peptide 3 and its receptor, anti-Müllerian hormone, gonadotropins, androgens in embryonic testicular migration. INSL3 and AMH are presented as markers of testicular dysfunction associated with cryptorchidism. Hypogonadotropic hypogonadism is also associated with cryptorchidism and can be diagnosed based on it. Results of modern investigations determine the necessary of hormonal and genetical examination of patients with isolated cryptorchidism to detect causes of cryptorchidism and manage of patients.

The effect of scrotal versus inguinal orchiopexy on the testicular function of children with clinically palpable, inguinal undescended testis: a randomized controlled trial

To compare the impact of the scrotal vs inguinal orchidopexy approach on the testicular function of infants with cryptorchidism, a randomized controlled trial was conducted involving boys who were 6-12 months old at surgery and were diagnosed with clinically palpable, inguinal undescended testis. Between June 2021 and December 2021, these boys at Fujian Maternity and Child Health Hospital (Fuzhou, China) and Fujian Children's Hospital (Fuzhou, China) were enrolled. Block randomization with a 1:1 allocation ratio was employed. The primary outcome was testicular function assessed by testicular volume, serum testosterone, anti-Müllerian hormone (AMH), and inhibin B (InhB) levels. Secondary outcomes included operative time, amount of intraoperative bleeding, and postoperative complications. Among 577 screened patients, 100 (17.3%) were considered eligible and enrolled in the study. Of the 100 children who completed the 1-year follow-up, 50 underwent scrotal orchidopexy and 50 underwent inguinal orchidopexy. The testicular volume, serum testosterone, AMH, and InhB levels in both groups increased markedly after surgery (all P < 0.05), but there were no apparent differences between groups at 6 months and 12 months after operation (all P > 0.05). No differences between the scrotal and inguinal groups were noted regarding the operative time ( P = 0.987) and amount of intraoperative bleeding ( P = 0.746). The overall complication rate (2.0%) of the scrotal group was slightly lower than that of the inguinal group (8.0%), although this difference was not statistically significant ( P > 0.05). Both scrotal and inguinal orchiopexy exerted protective effects on testicular function in children with cryptorchidism, with similar operative status and postoperative complications. Scrotal orchiopexy is an effective alternative to inguinal orchiopexy in children with cryptorchidism.

The Stability of the Anti-Müllerian Hormone in Serum and Plasma Samples under Various Preanalytical Conditions

The anti-Müllerian hormone (AMH) is a glycoprotein that plays an important role in prenatal sex differentiation. It is used as a biomarker in polycystic ovary syndrome (PCOS) diagnostics, as well as for estimating an individual's ovarian reserve and the ovarian response to hormonal stimulation during in vitro fertilization (IVF). The aim of this study was to test the stability of AMH during various preanalytical conditions that are in accordance with the ISBER (International Society for Biological and Environmental Repositories) protocol. Plasma and serum samples were taken from each of the 26 participants. The samples were then processed according to the ISBER protocol. AMH levels were measured in all the samples simultaneously using the chemiluminescent kit ACCESS AMH in a UniCel^® DxI 800 Immunoassay System (Beckman Coulter, Brea, CA, USA). The study proved that AMH retains a relatively high degree of stability during repeated freezing and thawing in serum. AMH was shown to be less stable in plasma samples. Room temperature proved to be the least suitable condition for the storage of samples before performing the biomarker analysis. During the testing of storage stability at 5-7 °C, the values decreased over time for all the plasma samples but remained stable in the serum samples. We proved that AMH is highly stable under various stress conditions. The anti-Müllerian hormone retained the greatest stability in the serum samples.

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.

Transcriptomic Analysis of Testicular Gene Expression in a Dog Model of Experimentally Induced Cryptorchidism

Cryptorchidism, a condition in which testes fail to descend from the abdomen into the scrotum, is a risk factor for infertility and germ cell cancer. Normally, tight junctions between adjacent Sertoli cells in the testes form a blood–testes barrier that regulates spermatogenesis; however, the effect of cryptorchidism on tight junctions is not well-understood. We established a model of heat-induced testicular damage in dogs using surgical cryptorchidism. We sequenced RNA to investigate whether certain transcripts are expressed at higher rates in heat-damaged versus normally descended testes. Claudins, cell adhesion molecules, were relatively highly expressed in cryptorchid testes: claudins 2, 3, 5, 11, and 18 were significantly increased in cryptorchid testes and reduced by orchiopexy. SOX9-positive Sertoli cells were present in the seminiferous tubules in both cryptorchid and control testes. Using real-time PCR and Western blot analysis to compare Sertoli cells cultured at 34 °C and 37 °C, we found that Sertoli cell claudins 2, 3, 5, 11, and 18 were significantly increased at 37 °C; however, accumulation was higher in the G0/G1 phase in Sertoli cells cultured at 34 °C. These results indicate that testicular hyperthermia caused by cryptorchidism affects claudin expression, regulated germ cell death, and the proliferation of Sertoli cells.

Testicular Sertoli Cell Hormones in Differences in Sex Development

The Sertoli cells of the testes play an essential role during gonadal development, in addition to supporting subsequent germ cell survival and spermatogenesis. Anti-Müllerian hormone (AMH) is a member of the TGF-β superfamily, which is secreted by immature Sertoli cells from the 8th week of fetal gestation. lnhibin B is a glycoprotein, which is produced by the Sertoli cells from early in fetal development. In people with a Difference or Disorder of Sex Development (DSD), these hormones may be useful to determine the presence of testicular tissue and potential for spermatogenesis. However, fetal Sertoli cell development and function is often dysregulated in DSD conditions and altered production of Sertoli cell hormones may be detected throughout the life course in these individuals. As such this review will consider the role of AMH and inhibin B in individuals with DSD.

Clinical Utility of Anti-Mullerian Hormone in Pediatrics

CONTEXT

Anti-Mullerian hormone (AMH) was originally described in the context of sexual differentiation in the male fetus but has gained prominence now as a marker of ovarian reserve and fertility in females. In this mini-review, we offer an updated synopsis on AMH and its clinical utility in pediatric patients.

DESIGN AND RESULTS

A systematic search was undertaken for studies related to the physiology of AMH, normative data, and clinical role in pediatrics. In males, AMH, secreted by Sertoli cells, is found at high levels prenatally and throughout childhood and declines with progression through puberty to overlap with levels in females. Thus, serum AMH has clinical utility as a marker of testicular tissue in males with differences in sexual development and cryptorchidism and in the evaluation of persistent Mullerian duct syndrome. In females, serum AMH has been used as a predictive marker of ovarian reserve and fertility, but prepubertal and adolescent AMH assessments need to be interpreted cautiously. AMH is also a marker of tumor burden, progression, and recurrence in germ cell tumors of the ovary.

CONCLUSIONS

AMH has widespread clinical diagnostic utility in pediatrics but interpretation is often challenging and should be undertaken in the context of not only age and sex but also developmental and pubertal stage of the child. Nonstandardized assays necessitate the need for assay-specific normative data. The recognition of the role of AMH beyond gonadal development and maturation may usher in novel diagnostic and therapeutic applications that would further expand its utility in pediatric care.

AMH Regulation by Steroids in the Mammalian Testis: Underlying Mechanisms and Clinical Implications

Anti-Müllerian hormone (AMH) is a distinctive biomarker of the immature Sertoli cell. AMH expression, triggered by specific transcription factors upon fetal Sertoli cells differentiation independently of gonadotropins or sex steroids, drives Müllerian duct regression in the male, preventing the development of the uterus and Fallopian tubes. AMH continues to be highly expressed by Sertoli until the onset of puberty, when it is downregulated to low adult levels. FSH increases testicular AMH output by promoting immature Sertoli cell proliferation and individual cell expression. AMH secretion also showcases a differential regulation exerted by intratesticular levels of androgens and estrogens. In the fetus and the newborn, Sertoli cells do not express the androgen receptor, and the high androgen concentrations do not affect AMH expression. Conversely, estrogens can stimulate AMH production because estrogen receptors are present in Sertoli cells and aromatase is stimulated by FSH. During childhood, sex steroids levels are very low and do not play a physiological role on AMH production. However, hyperestrogenic states upregulate AMH expression. During puberty, testosterone inhibition of AMH expression overrides stimulation by estrogens and FSH. The direct effects of sex steroids on AMH transcription are mediated by androgen receptor and estrogen receptor α action on AMH promoter sequences. A modest estrogen action is also mediated by the membrane G-coupled estrogen receptor GPER. The understanding of these complex regulatory mechanisms helps in the interpretation of serum AMH levels found in physiological or pathological conditions, which underscores the importance of serum AMH as a biomarker of intratesticular steroid concentrations.

Recent advancement in the treatment of boys and adolescents with hypogonadism

Clinical manifestations and the need for treatment varies according to age in males with hypogonadism. Early foetal-onset hypogonadism results in disorders of sex development (DSD) presenting with undervirilised genitalia whereas hypogonadism established later in foetal life presents with micropenis, cryptorchidism and/or micro-orchidism. After the period of neonatal activation of the gonadal axis has waned, the diagnosis of hypogonadism is challenging because androgen deficiency is not apparent until the age of puberty. Then, the differential diagnosis between constitutional delay of puberty and central hypogonadism may be difficult. During infancy and childhood, treatment is usually sought because of micropenis and/or cryptorchidism, whereas lack of pubertal development and relative short stature are the main complaints in teenagers. Testosterone therapy has been the standard, although off-label, in the vast majority of cases. However, more recently alternative therapies have been tested: aromatase inhibitors to induce the hypothalamic-pituitary-testicular axis in boys with constitutional delay of puberty and replacement with GnRH or gonadotrophins in those with central hypogonadism. Furthermore, follicle-stimulating hormone (FSH) priming prior to hCG or luteinizing hormone (LH) treatment seems effective to induce an enhanced testicular enlargement. Although the rationale for gonadotrophin or GnRH treatment is based on mimicking normal physiology, long-term results are still needed to assess their impact on adult fertility.

Open controversies on the treatment of undescended testis: An update

Cryptorchidism is a common congenital malformation in pediatric urology. Although there have been many studies on the etiology of the disease, it has not been fully clarified, and while its diagnostic and treatment models have gradually approached standardization and systematization, some controversies regarding treatment remain. Additionally, although ultrasound is a non-invasive examination without ionizing radiation, its role in the evaluation of cryptorchidism remains controversial. The main basis for treating cryptorchidism is orchidopexy, and the main view on treatment age is that treatment should be performed between 6 and 12 months after birth, but no more than 18 months after birth. The view on hormone therapy is still controversial because most scholars believe that early surgery is the key to treatment. There are many surgical treatment methods for cryptorchidism, including traditional open surgery and laparoscopic surgery, which provide satisfactory results. In conclusion, the treatment of undescended testis (UDT) had been largely standardized, apart from the treatment of high intra-abdominal testis (IAT), which remains a matter of debate.

Association of antimullerian hormone with the size of the appendix testis, the androgen and estrogen receptors and their expression in the appendix testis, in congenital cryptorchidism

OBJECTIVES

Antimullerian hormone (AMH) causes regression of the mullerian ducts in the male fetus. The appendix testis (AT) is a vestigial remnant of mullerian duct origin, containing both androgen (AR) and estrogen (ER) receptors. The role of both AMH and AT in testicular descent is yet to be studied. We investigated the possible association of AMH with AT size, the AR and ER, and their expression in the AT, in congenital cryptorchidism.

METHODS

A total of 26 patients with congenital unilateral cryptorchidism and 26 controls with orthotopic testes were investigated, and 21 ATs were identified in each group. AMH and insulin-like three hormone (INSL3) concentrations were measured with spectrophotometry. AR and ER receptor expression was assessed with immunohistochemistry using monoclonal antibodies R441 for AR and MAB463 for ER. For the estimation of receptor expression, the Allred Score method was used.

RESULTS

AMH concentrations did not present significant differences between patients with congenital cryptorchidism and the controls. Also, no correlation was found between AMH, INSL3, and AT length. Allred scores did not present significant differences. However, expression percentiles and intensity for both receptors presented significant differences. Three children with cryptorchidism and the highest AMH levels also had the highest estrogen receptor scores in the AT.

CONCLUSIONS

No association was found between AMH and the studied major parameters. However, higher AMH concentrations, in combination with higher estrogen receptor scores in the AT, may play a role in cryptorchidism in some children. Larger population samples are needed to verify this observation.

The G-Protein-Coupled Membrane Estrogen Receptor Is Present in Horse Cryptorchid Testes and Mediates Downstream Pathways

Cryptorchidism in horses is a commonly occurring malformation. The molecular basis of this pathology is not fully known. In addition, the origins of high intratesticular estrogen levels in horses remain obscure. In order to investigate the role of the G-protein-coupled membrane estrogen receptor (GPER) and establish histological and biochemical cryptorchid testis status, healthy and cryptorchid horse testes were subjected to scanning electron microscopy analysis, histochemical staining for total protein (with naphthol blue black; NBB), acid content (with toluidine blue O; TBO), and polysaccharide content (with periodic acid-Schiff; PAS). The expression of GPER was analyzed by immunohistochemistry and Western blot. GPER-mediated intracellular cAMP and calcium (Ca2+) signaling were measured immunoenzymatically or colorimetrically. Our data revealed changes in the distribution of polysaccharide content but not the protein and acid content in the cryptorchid testis. Polysaccharides seemed to be partially translocated from the interstitial compartment to the seminiferous tubule compartment. Moreover, the markedly decreased expression of GPER and GPER downstream molecules, cAMP and Ca2+, suggests their potential role in testis pathology. Increased estrogen levels in cryptorchid conditions may be linked to disturbed GPER signaling. We postulate that GPER is a prominent key player in testis development and function and may be used as a new biomarker of horse testis in health and disease.

Contribution of serum anti-Müllerian hormone in the management of azoospermia and the prediction of testicular sperm retrieval outcomes: a study of 155 adult men

Background

Testicular sperm extraction (TESE) is the method of choice for recovering spermatozoa in patients with azoospermia. However, the lack of reliable biomarkers makes it impossible to predict sperm retrieval outcomes at TESE. To date, little attention has been given to anti-Müllerian hormone (AMH) serum levels in adult men with altered spermatogenesis. In this study we aimed to investigate whether serum concentrations of AMH and the AMH to total testosterone ratio (AMH/T) might be predictive factors for sperm retrieval outcomes during TESE in a cohort of 155 adult Caucasian men with azoospermia.

Results

AMH serum levels were significantly lower in nonobstructive azoospermia (NOA) that was unexplained, cryptorchidism-related, cytotoxic and genetic (medians [pmol/l] = 30.1; 21.8; 26.7; 7.3; and p = 0.02; 0.001; 0.04; <0.0001, respectively]) compared with obstructive azoospermia (OA) (median = 44.8 pmol/l). Lowest values were observed in cases of genetic NOA (p < 0.0001, compared with unexplained NOA) and especially in individuals with non-mosaic Klinefelter syndrome (median = 2.3 pmol/l, p <0.0001). Medians of AMH/T values were significantly lower in genetic NOA compared to unexplained, cryptorchidism-related NOA as well as OA. Only serum concentrations of AMH differed significantly between positive and negative groups in men with non-mosaic Klinefelter syndrome. The optimal cut-off of serum AMH was set at 2.5 pmol/l. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this cut-off to predict negative outcomes of SR were 100 %, 76.9 %, 66.6 %, 100 and 84.2 %, respectively.

Conclusions

Serum AMH levels, but not AMH/T values, are a good marker for Sertoli and germ cell population dysfunction in adult Caucasian men with non-mosaic Klinefelter syndrome and could help us to predict negative outcomes of SR at TESE with 100 % sensitivity when serum levels of AMH are below 2.5 pmol/l.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12610-021-00133-9.

Androgen Treatment in Adolescent Males With Hypogonadism

During adolescence, androgens are responsible for the development of secondary sexual characteristics, pubertal growth, and the anabolic effects on bone and muscle mass. Testosterone is the most abundant testicular androgen, but some effects are mediated by its conversion to the more potent androgen dihydrotestosterone (DHT) or to estradiol. Androgen deficiency, requiring replacement therapy, may occur due to a primary testicular failure or secondary to a hypothalamic–pituitary disorder. A very frequent condition characterized by a late activation of the gonadal axis that may also need androgen treatment is constitutional delay of puberty. Of the several testosterone or DHT formulations commercially available, very few are employed, and none is marketed for its use in adolescents. The most frequently used androgen therapy is based on the intramuscular administration of testosterone enanthate or cypionate every 3 to 4 weeks, with initially low doses. These are progressively increased during several months or years, in order to mimic the physiology of puberty, until adult doses are attained. Scarce experience exists with oral or transdermal formulations. Preparations containing DHT, which are not widely available, are preferred in specific conditions. Oxandrolone, a non-aromatizable drug with higher anabolic than androgenic effects, has been used in adolescents with preserved testosterone production, like Klinefelter syndrome, with positive effects on cardiometabolic health and visual, motor, and psychosocial functions. The usual protocols applied for androgen therapy in boys and adolescents are discussed.

Testicular arteries anatomy applied to fowler-sthephens surgery in high undescended testis - a narrative review

Objectives:

In this review we will describe the testicular vessels anatomy and the implications of these vessels in surgical treatment of high undescended testis.

Material and Methods:

We performed a narrative review of the literature about the role of the testicular arteries anatomy in the treatment of high undescended testis. We also studied two human testes to illustrate the testicular vascularization.

Results:

Each testis is irrigated by three arteries: testicular artery (internal spermatic artery), a branch of the right aorta; deferential artery (vasal artery), a branch of the inferior vesicle artery that originates from the anterior trunk of internal iliac artery and cremasteric artery (external spermatic artery), a branch of the inferior epigastric artery. There are important communications among the three arteries with visible anastomotic channels between the testicular and deferential arteries.

Conclusions:

Laparoscopic transection of the testicular vessels by dividing the spermatic vessels (Fowler-Stephens surgery) is safe in patients with high abdominal testis due to the great collateral vascular supply between testicular, vasal and cremasteric arteries; also, two-stage Fowler-Stephens orchiopexy appears to carry a higher rate of success than the single stage approach.

A bird-like genome from a frog: Mechanisms of genome size reduction in the ornate burrowing frog, Platyplectrum ornatum

The diversity of genome sizes across the tree of life is of key interest in evolutionary biology. Various correlates of variation in genome size, such as accumulation of transposable elements (TEs) or rate of DNA gain and loss, are well known, but the underlying molecular mechanisms driving or constraining genome size are poorly understood. Here, we study one of the smallest genomes among frogs characterized thus far, that of the ornate burrowing frog (Platyplectrum ornatum) from Australia, and compare it to other published frog and vertebrate genomes to examine the forces driving reduction in genome size. At ∼1.06 gigabases (Gb), the P. ornatum genome is like that of birds, revealing four major mechanisms underlying TE dynamics: reduced abundance of all major classes of TEs; increased net deletion bias in TEs; drastic reduction in intron lengths; and expansion via gene duplication of the repertoire of TE-suppressing Piwi genes, accompanied by increased expression of Piwi-interacting RNA (piRNA)-based TE-silencing pathway genes in germline cells. Transcriptomes from multiple tissues in both sexes corroborate these results and provide insight into sex-differentiation pathways in Platyplectrum Genome skimming of two closely related frog species (Lechriodus fletcheri and Limnodynastes fletcheri) confirms a reduction in TEs as a major driver of genome reduction in Platyplectrum and supports a macroevolutionary scenario of small genome size in frogs driven by convergence in life history, especially rapid tadpole development and tadpole diet. The P. ornatum genome offers a model for future comparative studies on mechanisms of genome size reduction in amphibians and vertebrates generally.

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.

Serum Anti-Müllerian Hormone in the Prediction of Response to hCG Stimulation in Children With DSD

INTRODUCTION

The relationship between serum anti-Müllerian hormone (AMH) and the testosterone response to human chorionic gonadotropin (hCG) stimulation test is unclear.

METHODS

Children who had hCG stimulation tests in one tertiary centre from 2001 to 2018 were included (n = 138). Serum testosterone was measured before (day 1 [D1]) and after 3 days (D4) of hCG stimulation. Sixty-one of these children also had prolonged hCG stimulation for 2 more weeks and serum testosterone measured after 21 days (D22). All children had a serum AMH measured on D1.

RESULTS

Of the 138 children, D4 testosterone was normal in 104 (75%). AMH was low in 24/138 (17%) children, and 16 (67%) of these had a low D4 testosterone. Median AMH in those who had a normal vs low D4 testosterone was 850 pmol/L (24, 2280) and 54 pmol/L (0.4, 1664), respectively (P < 0.0001). An AMH > 5th centile was associated with a low D4 testosterone in 18/118 (13%; P < 0.0001). Of the 61 children who had prolonged hCG stimulation, D22 testosterone was normal in 39 (64%). AMH was low in 10/61(16%) children and 9 (90%) of these had a low D22 testosterone. Median AMH in children who responded and did not respond by D22 was 639 pmol/L (107, 2280) and 261 pmol/L (15, 1034) (P < 0.0001).

CONCLUSION

A normal AMH may provide valuable information on overall testicular function. However, a low AMH does not necessarily predict a suboptimal testosterone response to hCG stimulation.

Clinical, hormonal and genetic characteristics of androgen insensitivity syndrome in 39 Chinese patients

BACKGROUND

Abnormal androgen receptor (AR) genes can cause androgen insensitivity syndrome (AIS), and AIS can be classified into complete androgen insensitivity syndrome (CAIS), partial androgen insensitivity syndrome (PAIS) and mild AIS. We investigated the characteristics of clinical manifestations, serum sex hormone levels and AR gene mutations of 39 AIS patients, which provided deeper insight into this disease.

METHODS

We prospectively evaluated 39 patients with 46, XY disorders of sex development (46, XY DSD) who were diagnosed with AIS at the Department of Endocrinology of Shanghai Children's Hospital from 2014 to 2019. We analysed clinical data from the patients including hormone levels and AR gene sequences. Furthermore, we screened the AR gene sequences of the 39 AIS patients to identify probable mutations.

RESULTS

The 39 AIS patients came from 37 different families; 19 of the patients presented CAIS, and 20 of them presented PAIS. The CAIS patients exhibited a higher cryptorchidism rate than the PAIS (100 and 55%, P = 0.001). There were no significant difference between the CAIS and PAIS groups regarding the levels of inhibin B (INHB), sex hormone-binding globulin (SHBG), basal luteinizing hormone (LH), testosterone (T), or basal dihydrotestosterone (DHT), the T:DHT ratio, DHT levels after human chorionic gonadotropin (HCG) stimulation or T levels after HCG stimulation. However, the hormone levels of AMH (P = 0.010), peak LH (P = 0.033), basal FSH (P = 0.009) and peak FSH (P = 0.033) showed significant differences between the CAIS group and the PAIS group. Twenty-one reported pathogenic and 9 novel AR mutations were identified. Spontaneous AR mutations were found in 5 AIS patients, and 21 patients inherited mutations from their mothers, who carried heterozygous mutations.

CONCLUSIONS

Forty-six XY DSD patients with cryptorchidism and female phenotypes were highly suspected of having AIS. We demonstrated that CAIS patients could not be distinguished by their hormone levels alone. Compared with PAIS patients, CAIS patients exhibited higher basal FSH, peak FSH, and peak LH hormone levels but lower AMH expression. We identified 21 reported pathogenic AR mutations and 9 novel AR mutations that led to different types of AIS. Missense mutations were the major cause of AIS and mostly occurred in exon 7 of the AR gene. These findings provided deeper insight into the diagnosis and classification of AIS and will even contributed to its clinical assessment.

Correlation of anti-Mullerian hormone with humanchorionic gonadotropin test in the evaluation of testicular function of children with 46 XY male hypogonadism: Use of anti-Mullerian hormone as abiomarker

AIM

It is challenging to evaluate reproductive potential during childhood. These challenges necessitate the use of invasive dynamic tests. Although the anti-Mullerian hormone (AMH) is a reliable biomarker in evaluating testicular function, especially in the pre-pubertal period, there are uncertainties concerning its use in a clinical setting. This study is focused on comparing the AMH and human chorionic gonadotropin (hCG) test in boys with hypogonadism.

METHODS

A total of 160 boys aged between 0 and 18 years who presented with complaints associated with hypogonadism were prospectively enrolled in the study. All children were assigned to the following five groups: gonadal disorders (n = 34), androgen synthesis and end organ effect disorder (n = 48), isolated genital malformation disorders (n = 57), hypogonadotropic hypogonadism (n = 15) and constitutional delayed puberty (n = 6). All children underwent a short 3-day hCG test (1500 U/m² /day). The concordance and correlation were evaluated between the hCG test and AMH.

RESULTS

All groups exhibited a strong correlation (r₁₆₀ = 0.689) and strong concordance (Kappa coefficient₁₆₀ = 0.7) between the AMH and hCG test. Values of AMH higher than 32.7 pmol/L and hCG responses higher than 86 pmol/L were significant as indicative markers of functional testicular tissue presence.

CONCLUSIONS

This study has shown that there is a strong correlation between the AMH and short-term hCG test and that values of AMH higher than 32.7 pmol/L and stimulated testosterone higher than 86 pmol/L can be used as indicators of functionally sufficient testicular tissue. These results indicate that AMH value can be used as a reliable and useful biomarker in the evaluation of the testicular function in 46 XY hypogonadism.

What Does AMH Tell Us in Pediatric Disorders of Sex Development?

Disorders of sex development (DSD) are conditions where genetic, gonadal, and/or internal/external genital sexes are discordant. In many cases, serum testosterone determination is insufficient for the differential diagnosis. Anti-Müllerian hormone (AMH), a glycoprotein hormone produced in large amounts by immature testicular Sertoli cells, may be an extremely helpful parameter. In undervirilized 46,XY DSD, AMH is low in gonadal dysgenesis while it is normal or high in androgen insensitivity and androgen synthesis defects. Virilization of a 46,XX newborn indicates androgen action during fetal development, either from testicular tissue or from the adrenals or placenta. Recognizing congenital adrenal hyperplasia is usually quite easy, but other conditions may be more difficult to identify. In 46,XX newborns, serum AMH measurement can easily detect the existence of testicular tissue, leading to the diagnosis of ovotesticular DSD. In sex chromosomal DSD, where the gonads are more or less dysgenetic, AMH levels are indicative of the amount of functioning testicular tissue. Finally, in boys with a persistent Müllerian duct syndrome, undetectable or very low serum AMH suggests a mutation of the AMH gene, whereas normal AMH levels orient toward a mutation of the AMH receptor.

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

STUDY QUESTION

Does standardised treatments used in children and adolescents with haematologic malignancies, including acute lymphoblastic (ALL) or myeloid leukaemia (AML) and non-Hodgkin lymphoma (NHL), affect endocrine function of the developing testes?

SUMMARY ANSWER

Therapy of haematologic malignancies do not provoke an overt damage of Sertoli and Leydig cell populations, as revealed by normal levels of anti-Müllerian hormone (AMH) and testosterone, but a mild primary testicular dysfunction may be observed, compensated by moderate gonadotropin elevation, during pubertal development.

WHAT IS KNOWN ALREADY

Evidence exists on the deleterious effect that chemotherapy and radiotherapy have on germ cells, and some attention has been given to the effects on Leydig and Sertoli cells of the adult gonads, but information is virtually non-existent on the effects of oncologic treatment on testicular somatic cell components during childhood and adolescence.

STUDY DESIGN, SIZE, DURATION

A retrospective, analytical, observational study included 97 boys with haematological malignancies followed at two tertiary paediatric public hospitals in Buenos Aires, Argentina, between 2002 and 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clinical records of males aged 1-18 years, referred with the diagnoses of ALL, AML or NHL for the assessment of gonadal function, were eligible. We assessed serum levels of AMH and FSH as biomarkers of Sertoli cell endocrine function and testosterone and LH as biomarkers of Leydig cell function.

MAIN RESULTS AND THE ROLE OF CHANCE

All hormone levels were normal in the large majority of patients until early pubertal development. From Tanner stage G3 onwards, while serum AMH and testosterone kept within the normal ranges, gonadotropins reached mildly to moderately elevated values in up to 35.9% of the cases, indicating a compensated Sertoli and/or Leydig cell dysfunction, which generally did not require hormone replacement therapy.

LIMITATIONS, REASONS FOR CAUTION

Serum inhibin B determination and semen analysis were not available for most patients; therefore, we could not conclude on potential fertility impairment or identify whether primary Sertoli cell dysfunction resulted in secondary depleted spermatogenesis or whether primary germ cell damage impacted Sertoli cell function.

WIDER IMPLICATIONS OF THE FINDINGS

The regimens used in the treatment of boys and adolescents with ALL, AML or NHL in the past two decades seem relatively safe for endocrine testicular function; nonetheless, a mild primary testicular endocrine dysfunction may be observed, usually compensated by slightly elevated gonadotropin secretion by the pituitary in adolescents, and not requiring hormone replacement therapy. No clinically relevant risk factor, such as severity of the disease or treatment protocol, could be identified in association with the compensated endocrine dysfunction.

STUDY FUNDING/COMPETING INTEREST(S)

This work was partially funded by grants PIP 11220130100687 of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and PICT 2016-0993 of Fondo para la Investigación Científica y Tecnológica (FONCYT), Argentina. R.A.R., R.P.G. and P.B. have received honoraria from CONICET (Argentina) for technology services using the AMH ELISA. L.A.A. is part-time employee of CSL Behring Argentina. The other authors have no conflicts of interest to disclose.

Hypogonadism in Pediatric Health: Adult Medicine Concepts Fail

The classical definition of hypogonadism, used in adult medicine, as gonadal failure resulting in deficient steroid and gamete production, and its classification into hypergonadotropic and hypogonadotropic refer to primary gonadal and hypothalamic-pituitary disorders respectively and may lead to under- or misdiagnosis in pediatrics. Indeed, in children with primary gonadal failure, gonadotropin levels may be within the reference range for age. Conversely, since gonadotropins and steroids are normally low during childhood, it may prove impossible to show the existence of a hypogonadotropic state before pubertal age. Anti-Müllerian hormone (AMH) and inhibin B arise as more adequate biomarkers to assess gonadal function and increase the possibility of making an earlier diagnosis of hypogonadism in children, which may positively impact on timely management.

Importance of the Androgen Receptor Signaling in Gene Transactivation and Transrepression for Pubertal Maturation of the Testis

Androgens are key for pubertal development of the mammalian testis, a phenomenon that is tightly linked to Sertoli cell maturation. In this review, we discuss how androgen signaling affects Sertoli cell function and morphology by concomitantly inhibiting some processes and promoting others that contribute jointly to the completion of spermatogenesis. We focus on the molecular mechanisms that underlie anti-Müllerian hormone (AMH) inhibition by androgens at puberty, as well as on the role androgens have on Sertoli cell tight junction formation and maintenance and, consequently, on its effect on proper germ cell differentiation and meiotic onset during spermatogenesis.

Primary gonadal failure

The term primary gonadal failure encompasses not only testicular insufficiency in 46,XY males and ovarian insufficiency in 46,XX females, but also those disorders of sex development (DSD) which result in gender assignment that is at variance with the genotype and gonadal type. In boys, causes of gonadal failure include Klinefelter and other aneuploidy syndromes, bilateral cryptorchidism, testicular torsion, and forms of 46,XY DSD such as partial androgen insensitivity. Causes in girls include Turner syndrome and other aneuploidies, galactosemia, and autoimmune ovarian failure. Iatrogenic causes in both boys and girls include the late effects of childhood cancer treatment, total body irradiation prior to bone marrow transplantation, and iron overload in transfusion-dependent thalassaemia. In this paper, a brief description of the physiology of testicular and ovarian development is followed by a section on the causes and practical management of gonadal impairment in boys and girls. Protocols for pubertal induction and post-pubertal hormone replacement - intramuscular, oral and transdermal testosterone in boys; oral and transdermal oestrogen in girls - are then given. Finally, current and future strategies for assisted conception and fertility preservation are discussed.

Comparing the role of anti-Müllerian hormone as a marker of FSH action in male and female fertility

INTRODUCTION

Originally limited to the assessment of disorders of sex development, anti-Müllerian hormone (AMH) measurement has more recently been extended to several conditions affecting the reproductive axis in males and females. Follicle-stimulating hormone (FSH) regulation of gonadal function has been extensively studied, but its role on AMH production has been explored only recently.

AREAS COVERED

We addressed the relationship between FSH action on the gonads and the usefulness of AMH as a marker in conditions affecting the reproductive axis.

EXPERT OPINION

Sertoli cells are the most active cell population in the prepubertal testis. Serum AMH is an excellent marker of FSH action on Sertoli cell proliferation and function in patients with hypogonadotropic hypogonadism. Low serum AMH is expected to predict low sperm production and prompts initial FSH treatment followed by human chorionic gonadotropin (hCG) or luteinizing hormone (LH) addition. Gonadotropin treatment may be more effective if installed to mimic the postnatal activation stage of the hypothalamic-pituitary-testicular axis. In females, AMH secretion by small antral follicles is stimulated by FSH. Elevated AMH indicates increased follicle numbers and should be considered as a potential contraindication of gonadotropin treatment in infertile patients due to an increased risk of developing ovarian hyperstimulation syndrome.

Postnatal Testicular Activity in Healthy Boys and Boys With Cryptorchidism

Cryptorchidism, or undescended testis, is a well-known risk factor for testicular cancer and impaired semen quality in adulthood, conditions which have their origins in early fetal and postnatal life. In human pregnancy, the interplay of testicular and placental hormones as well as local regulatory factors and control by the hypothalamic-pituitary (HP) axis, lead to testicular descent by term. The normal masculine development may be disrupted by environmental factors or genetic defects and result in undescended testes. Minipuberty refers to the postnatal re-activation of the HP-testicular (T) axis after birth. During the first weeks of life, gonadotropin levels increase, followed by activation and proliferation of testicular Leydig, Sertoli and germ cells. Consequent rise in testosterone levels results in penile growth during the first months of life. Testicular size increases and testicular descent continues until three to five months of age. Insufficient HPT axis activation (e.g., hypogonadotropic hypogonadism) is often associated with undescended testis and therefore minipuberty is considered an important phase in the normal male reproductive development. Minipuberty provides a unique window of opportunity for the early evaluation of HPT axis function during early infancy. For cryptorchid boys, hormonal evaluation during minipuberty may give a hint of the underlying etiology and aid in the evaluation of the later risk of HPT axis dysfunction and impaired fertility. The aim of this review is to summarize the current knowledge of the role of minipuberty in testicular development and descent.

Hypogonadism and Cryptorchidism

Congenital cryptorchidism (undescended testis) is one of the most common congenital urogenital malformations in boys. Prevalence of cryptorchidism at birth among boys born with normal birth weight ranges from 1.8 to 8.4%. Cryptorchidism is associated with a risk of low semen quality and an increased risk of testicular germ cell tumors. Testicular hormones, androgens and insulin-like peptide 3 (INSL3), have an essential role in the process of testicular descent from intra-abdominal position into the scrotum in fetal life. This explains the increased prevalence of cryptorchidism among boys with diseases or syndromes associated with congenitally decreased secretion or action of androgens, such as patients with congenital hypogonadism and partial androgen insensitivity syndrome. There is evidence to support that cryptorchidism is associated with decreased testicular hormone production later in life. It has been shown that cryptorchidism impairs long-term Sertoli cell function, but may also affect Leydig cells. Germ cell loss taking place in the cryptorchid testis is proportional to the duration of the condition, and therefore early orchiopexy to bring the testis into the scrotum is the standard treatment. However, the evidence for benefits of early orchiopexy for testicular endocrine function is controversial. The hormonal treatments using human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone (GnRH) to induce testicular descent have low success rates, and therefore they are not recommended by the current guidelines for management of cryptorchidism. However, more research is needed to assess the effects of hormonal treatments during infancy on future male reproductive health.

Male Central Hypogonadism in Paediatrics - the Relevance of Follicle-stimulating Hormone and Sertoli Cell Markers

The definition of male hypogonadism, used in adult endocrinology, is not fully applicable to paediatrics. A clear understanding of the developmental physiology of the hypothalamic-pituitary-testicular axis is essential for the comprehension of the pathogenesis of hypogonadal states in boys and for the establishment of adequate definitions and classifications in paediatric ages. This is particularly true for central hypogonadism, usually called hypogonadotropic in adults. Because childhood is a period characterised by a physiological state of low gonadotropin and testosterone production, these markers of hypogonadism, typically used in adult endocrinology, are uninformative in the child. This review is focused on the physiological importance of prepubertal Sertoli cell markers - anti-Müllerian hormone (AMH) and inhibin B - and of the intratesticular actions of follicle-stimulating hormone (FSH) and testosterone during early infancy and the first stages of pubertal development. We discuss the role of FSH in regulating the proliferation of Sertoli cells - the main determinant of prepubertal testicular volume - and the secretion of AMH and inhibin B. We also address how intratesticular testosterone concentrations have different effects on the seminiferous tubule function in early infancy and during pubertal development.