Measurement of Mullerian inhibiting substance facilitates management of boys with microphallus and cryptorchidism

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.

Testicular Regression Syndrome: Two Case Studies

Testicular agenesis, also called testicular regression syndrome (TRS), is a rare disease. It is defined by the complete absence of testicular tissue associated with a 46,XY karyotype. The phenotype is variable depending on when gonadal regression occurs in utero. Several etiologies have been identified. Here, we report two cases of TRS with an initial diagnosis of cryptorchidism and bilateral impalpable testes. The hormonal assessment showed an undetectable anti-Müllerian hormone (AMH) level and high gonadotropins. Also, radiological exploration did not show the testicles in a normal position, which was confirmed by a negative laparoscopy, establishing the diagnosis of TRS. Androgen replacement therapy along with psychological support to the patient is recommended is such cases.

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.

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.

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.

TESTICULAR REGRESSION SYNDROME: PRACTICE VARIATION IN DIAGNOSIS AND MANAGEMENT

Objective: The purpose of this study was to assess clinical practice patterns with regard to diagnosis and management of testicular regression syndrome (TRS), a condition in 46,XY males with male phenotypic genitalia and bilateral absence of testes. Methods: A retrospective review was conducted at two large pediatric academic centers to examine diagnostic and management approaches for TRS. Results: Records of 57 patients were reviewed. Diagnostic methods varied widely between patients and included hormonal testing, karyotype, imaging, and surgical exploration, with multiple diagnostic methods frequently used in each patient. Of the 30 subjects that had reached adolescence at the time of the study, 17 (57%) had gaps in care of more than 5 years during childhood. Thirty subjects had received testosterone replacement therapy at a mean age of 12.1 ± 1.0 years. Forty-seven percent had a documented discussion of infertility. Eighty-two percent discussed prosthesis placement, with 35% having prostheses placed. Twenty-three percent were seen by a psychosocial provider. The between-site differences were age at fertility discussion, age at and number of prostheses placed, and type/age of testosterone initiation. Conclusion: Our findings highlight the wide variation in diagnostic approaches, follow-up frequency, testosterone initiation, fertility counseling, and psychosocial support for patients with TRS. Developing evidence-based guidelines for the evaluation and management of TRS would help reduce inconsistencies in care and unnecessary testing. Ongoing follow-up and coordination of care, even during the years when no hormonal treatment is being administered, could lead to opportunities for psychosocial support and improved interdisciplinary approach to care. Abbreviations: AMH = antimüllerian hormone; CAH = congenital adrenal hyperplasia; DSD = differences/disorders of sex development; hCG = human chorionic gonadotropin; TRS = testicular regression syndrome.

Early Identification of Isolated Sertoli Cell Dysfunction in Prepubertal and Transition Age: Is It Time?

The male transitional phase is of fundamental importance for future fertility. This aspect is largely neglected in clinical practice. This opinion aims to shed light on these issues. The children frequently complete the transition phase with a slight reduction of testicular volume. The system of detecting testicular volume is often inadequate. These patients evidently complete puberty in an incomplete way because they do not reach an adequate testicular volume, albeit in the presence of adequate height and regular secondary sexual characteristics.

Evaluation of testicular function in prepubertal children

INTRODUCTION

The assessment of testicular function is not currently performed in childhood. The aim of this review was to address the usefulness of serum Anti-Müllerian Hormone (AMH), inhibin B, and testicular volume (TV) evaluation in children.

REVIEW

Serum AMH and inhibin B levels reflect Sertoli cells (SCs) health and number, SCs maturation degree and their exposure to FSH and to intra-tubular testosterone (T). These hormones might be helpful in discriminating between congenital central hypogonadism (cHH) and constitutional delay in growth and puberty (CDGP) and in case of clinical suspicious of precocious puberty. Furthermore, low AMH and/or inhibin B levels have been observed in children with primary testicular disorders, suggesting the existence of SC dysfunction. TV also provides useful information on testicular health. Recently, a medical calculator, requiring testis length and the stage of genital development, has been developed to easily derive TV.

CONCLUSIONS

The evidence supports the usefulness of AMH, inhibin B and TV evaluation for the early diagnosis of puberty disorders and primary testicular damage. We suggest the measurement of TV by using the medical calculator in all children and to reserve AMH and inhibin B measurements to those cases of no testicular growth, clinical suspicious of puberty disorders or in children at risk for spermatogenesis damage. This work-up might allow the early detection of testicular tubular damage which, in turn, may be useful to prevent the oncoming male infertility in adulthood.

The AMH genotype (rs10407022 T>G) is associated with circulating AMH levels in boys, but not in girls

OBJECTIVE

Fetal anti-Müllerian hormone (AMH) is responsible for normal male sexual differentiation, and circulating AMH is used as a marker of testicular tissue in newborns with disorders of sex development. Little is known about the mechanism of action in postnatal life. A recent genome wide association study (GWAS) reported genetic variation of AMH affecting AMH levels in young men. This study investigated the effect of genetic variation of AMH and AMH type II receptor (AMHR2) (AMHrs10407022 T>G and AMHR2rs11170547 C>T) on circulating reproductive hormone levels and pubertal onset in boys and girls.

DESIGN AND METHODS

This study is a combined longitudinal and cross-sectional study in healthy Danish boys and girls from the general population. We included 658 boys aged 5.8-19.8 years and 320 girls aged 5.6-16.5 years. The main outcome measures were genotyping of AMH and AMHR2, pubertal staging and serum levels of reproductive hormones.

RESULTS

AMHrs10407022T>G was associated with higher serum levels of AMH in prepubertal boys (TT: 575 pmol/L vs TG: 633 pmol/L vs GG: 837 pmol/L, P = 0.002) and adolescents (TT: 44 pmol/L vs TG: 58 pmol/L vs GG: 79 pmol/L, P < 0.001). Adolescent boys carrying the genetic variation also had lower levels of LH (TT: 3.0 IU/L vs TG: 2.8 IU/L vs GG: 1.8 IU/L, P = 0.012). Hormone levels in girls and pubertal onset in either sex did not seem to be profoundly affected by the genotypes.

CONCLUSION

Our findings support recent GWAS results in young adults and expand our understanding of genetic variation affecting AMH levels even in boys prior to the pubertal decline of circulating AMH.

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

INTRODUCTION

The functional capacity of the testes in prepubertal boys with cryptorchidism before treatment has received very little attention. The assessment of testicular function at diagnosis could be helpful in the understanding of the pathophysiology of cryptorchidism and in the evaluation of the effect of treatment. Anti-Müllerian hormone is a well-accepted Sertoli cell biomarker to evaluate testicular function during childhood without the need for stimulation tests.

OBJECTIVE

The aim of the study was to assess testicular function in prepubertal children with cryptorchidism before orchiopexy, by determining serum anti-Müllerian hormone (AMH). We also evaluated serum gonadotropins and testosterone and looked for associations between testicular function and the clinical characteristics of cryptorchidism.

MATERIALS AND METHODS

We performed a retrospective, cross-sectional, analytical study at a tertiary pediatric public hospital. All clinical charts of patients admitted at the outpatient clinic, and recorded in our database with the diagnosis of cryptorchidism, were eligible. The main outcome measure of the study was the serum concentration of AMH. Secondary outcome measures were serum LH, FSH, and testosterone. For comparison, serum hormone levels from a normal population of 179 apparently normal prepubertal boys were used.

RESULTS

Out of 1,557 patients eligible in our database, 186 with bilateral and 124 with unilateral cryptorchidism were selected using a randomization software. Median AMH standard deviation score was below 0 in both the bilaterally and the unilaterally cryptorchid groups, indicating that testicular function was overall decreased in patients with cryptorchidism. Serum AMH was significantly lower in boys with bilateral cryptorchidism as compared with controls and unilaterally cryptorchid patients between 6 months and 1.9 years and between 2 and 8.9 years of age. Serum AMH below the normal range reflected testicular dysfunction in 9.5-36.5% of patients according to the age group in bilaterally cryptorchid boys and 6.3-16.7% in unilaterally cryptorchid boys. FSH was elevated in 8.1% and LH in 9.1% of boys with bilateral cryptorchidism, most of whom were anorchid. In patients with present testes, gonadotropins were only mildly elevated in less than 5% of the cases. Basal testosterone was mildly decreased in patients younger than 6 months old, and uninformative during childhood.

CONCLUSION

Prepubertal boys with cryptorchidism, especially those with bilaterally undescended gonads, have decreased AMH production. Although serum AMH may fall within the normal range, there is a considerable prevalence of testicular dysfunction during childhood in this frequent condition.

Anti-Müllerian hormone as a marker of steroid and gonadotropin action in the testis of children and adolescents with disorders of the gonadal axis

In pediatric patients, basal testosterone and gonadotropin levels may be uninformative in the assessment of testicular function. Measurement of serum anti-Müllerian hormone (AMH) has become increasingly widespread since it provides information about the activity of the male gonad without the need for dynamic tests, and also reflects the action of FSH and androgens within the testis. AMH is secreted in high amounts by Sertoli cells from fetal life until the onset of puberty. Basal AMH expression is not dependent on gonadotropins or sex steroids; however, FSH further increases and testosterone inhibits AMH production. During puberty, testosterone induces Sertoli cell maturation, and prevails over FSH on AMH regulation. Therefore, AMH production decreases. Serum AMH is undetectable in patients with congenital or acquired anorchidism, or with complete gonadal dysgenesis. Low circulating levels of AMH may reflect primary testicular dysfunction, e.g. in certain patients with cryptorchidism, monorchidism, partial gonadal dysgenesis, or central hypogonadism. AMH is low in boys with precocious puberty, but it increases to prepubertal levels after successful treatment. Conversely, serum AMH remains at high, prepubertal levels in boys with constitutional delay of puberty. Serum AMH measurements are useful, together with testosterone determination, in the diagnosis of patients with ambiguous genitalia: both are low in patients with gonadal dysgenesis, including ovotesticular disorders of sex development, testosterone is low but AMH is in the normal male range or higher in patients with disorders of androgen synthesis, and both hormones are normal or high in patients with androgen insensitivity. Finally, elevation of serum AMH above normal male prepubertal levels may be indicative of rare cases of sex-cord stromal tumors or Sertoli cell-limited disturbance in the McCune Albright syndrome.

The Sertoli cell hormones inhibin-B and anti Müllerian hormone have different patterns of secretion in prepubertal cryptorchid boys

OBJECTIVES AND HYPOTHESES

The Sertoli-cells produce inhibin-B and Anti-Müllerian-Hormone (AMH). Much is still unknown about these hormones in prepubertal cryptorchids. The Sertoli-cells are mandatory for germ cell development. The aim of the study was to investigate if there are differences in secretion pattern of Sertoli-cell hormones and their gonadotropin feed-back mechanisms.

METHODS

Included were 94 prepubertal cryptorchid boys 0.5-13.1years with measurements of serum-inhibin-B, Anti-Müllerian-Hormone (AMH), Luteinizing Hormone (LH) and Follicle Stimulation Hormone (FSH). The serum values were measured using commercially available kits. The hormonal values were related to age-matched normal values. Testicular biopsy was taken at orchiopexy.

RESULTS

Inhibin-B positively correlated to AMH for 1-13year-old patients (p<0.0001), but not for 0.5-1year-old patients (p=0.439). For 0.5-1year-old patients inhibin-B-values tended to decrease (p=0.055), in contrast to AMH-values (p=0.852). LH was elevated more often than FSH (p=0.014). FSH and LH were positively associated in patients both 0.5-1year (p=0.042) and 1-13years of age (p<0.0001). LH correlated positively to inhibin- B (p=0.001). In contrast, FSH did not correlate to inhibin-B or AMH (p=0.755 and p=0.528). The number of A-dark spermatogonia per tubular transverse section was positively correlated to inhibin-B serum level.

CONCLUSION

Our new finding of an association between LH and inhibin-B in infancy of cryptorchid boys may be essential for the transformation of gonocytes to A-dark spermatogonia. Previously, LH associated to inhibin-B was described in early puberty only. During the first year of life inhibin-B values decreased faster than AMH. The AMH-levels may just reflect the increased Sertoli cell number that occurs during the first 3months of life.

Current Management of Undescended Testes

Undescended testes (UDTs) are a relatively common finding in newborn males, especially in those born prematurely. Upon discovering a non-intrascrotal testis, it is important to determine whether the testis is palpable or non-palpable and whether the finding is unilateral or bilateral. Imaging should not be used in this workup, as no current modality has been shown to be adequately sensitive or specific to aid in management decisions. Patients with UDTs diagnosed after 6 months of age should be referred to a specialist for correction so that surgery may be performed within 1 year thereafter. This allows testes to descend spontaneously if they are to do so while facilitating early intervention to decrease the risk of subfertility and testicular malignancy for those patients in whom spontaneous descent does not occur. The surgical approach is often dependent on the location of the testis on physical exam. Most orchiopexies for palpable testes are performed through an inguinal incision, although a scrotal approach can be safely utilized depending on the testis position. Diagnostic laparoscopy is most often used for non-palpable testes, as it not only allows for the identification of an atrophic or absent testicle, but it also provides an opportunity to perform an orchiopexy simultaneously should a viable testis be found. Hormonal therapy is not recommended for treatment of UDTs due to its low success rate, the incidence of secondary re-ascent, and the possible detrimental effects on spermatogenesis. Finally, patients with bilateral non-palpable UDTs require a more extensive preliminary evaluation to rule out congenital adrenal hyperplasia (CAH) and disorders of sexual development (DSD). This involves serum electrolytes, karyotype analysis and hormonal testing including a serum müllerian inhibiting substance (MIS), in order to determine if testicular tissue is present and functional.

[Embryonic testicular regression syndrome: report of 6 cases]

Le syndrome de régression embryonnaire des testicules ou anorchidie bilatérale congénitale (ABC) est un syndrome très rare défini par l'absence complète de tissu testiculaire chez un patient présentant un caryotype masculin normal. Le phénotype est variable en fonction du moment où la régression gonadique survient in utero. Actuellement, son déterminisme reste encore mystérieux mais sa survenue familiale est un argument pour suggérer une étiologie génétique. Nous en rapportons six cas, illustrant la variabilité phénotypique et décrivant la démarche et les nouveaux marqueurs diagnostiques ainsi que la conduite à tenir thérapeutique.

The regulation of testicular descent and the effects of cryptorchidism

The first half of this review examines the boundary between endocrinology and embryonic development, with the aim of highlighting the way hormones and signaling systems regulate the complex morphological changes to enable the intra-abdominal fetal testes to reach the scrotum. The genitoinguinal ligament, or gubernaculum, first enlarges to hold the testis near the groin, and then it develops limb-bud-like properties and migrates across the pubic region to reach the scrotum. Recent advances show key roles for insulin-like hormone 3 in the first step, with androgen and the genitofemoral nerve involved in the second step. The mammary line may also be involved in initiating the migration. The key events in early postnatal germ cell development are then reviewed because there is mounting evidence for this to be crucial in preventing infertility and malignancy later in life. We review the recent advances in what is known about the etiology of cryptorchidism and summarize the syndromes where a specific molecular cause has been found. Finally, we cover the recent literature on timing of surgery, the issues around acquired cryptorchidism, and the limited role of hormone therapy. We conclude with some observations about the differences between animal models and baby boys with cryptorchidism.

The prepubertal testis: biomarkers and functions

PURPOSE OF REVIEW

Biomarkers of prepubertal testicular function have become widely available only in recent years. The aim of this review is to update the knowledge on key biomarkers used to assess hypogonadism in boys.

RECENT FINDINGS

Sertoli cells are the most representative cells of the prepubertal testis. Anti-Müllerian hormone and inhibin B are essential biomarkers of Sertoli cell function. Also, INSL3 arises as an additional marker of Leydig cell dysfunction.

SUMMARY

The widespread use of these biomarkers has enhanced our knowledge on the pathophysiology and diagnosis of prepubertal male hypogonadism. Beyond their well known germ-cell toxicity, oncologic treatments may also affect Sertoli cell function. Pathophysiology is not the same in all aneuploidies leading to infertility: while hypogonadism is not evident until mid-puberty in Klinefelter syndrome, it is established in early infancy in Down syndrome. In Noonan syndrome, the occurrence of primary hypogonadism depends on the existence of cryptorchidism, and Prader-Willi syndrome may present with either primary or combined forms of hypogonadism. Prepubertal testicular markers have also provided insights into the effects of environmental disruptors on gonadal function from early life, and helped dissipate concerns about testicular function in boys born preterm or small for gestational age or conceived by assisted reproductive technique procedures.

Serum anti-Müllerian hormone concentrations in stallions: developmental changes, seasonal variation, and differences between intact stallions, cryptorchid stallions, and geldings

Anti-Müllerian hormone (AMH), a homodimeric glycoprotein, is secreted early in fetal life when it exerts a crucial function in sexual differentiation. The secretion of AMH in male humans persists after birth and is characterized by high prepubertal concentrations followed by a significant decrease at the onset of puberty. The expression of AMH in the normal and cryptorchid equine testis is well characterized but data regarding circulating AMH concentrations are lacking. The objectives of this study were to determine serum AMH concentrations in neonatal colts and fillies, prepubertal colts, and postpubertal stallions, and to evaluate variations in serum AMH related to season and gonadal status of stallions. In addition, we examined the presence and determined concentrations of AMH in seminal plasma of mature stallions. Serum AMH concentrations were significantly higher in neonatal colts than in neonatal fillies. Moreover, concentrations of AMH are high in prepubertal colts whereas significantly lower concentrations were detected after puberty. In intact mature stallions, season influenced AMH concentrations with significantly higher concentrations during spring and summer. Serum AMH concentrations were significantly higher in cryptorchid stallions compared with intact stallions or geldings. Finally, AMH was identified in seminal plasma of intact mature stallions, but there was no significant correlation between serum and seminal plasma AMH concentrations. In conclusion, serum AMH concentration varies with sex in the neonatal period, postnatal sexual development and season, and serum AMH concentration can be used as a biomarker for the presence of testicular tissue.

Anti-müllerian hormone and its clinical use in pediatrics with special emphasis on disorders of sex development

Using measurements of circulating anti-Müllerian hormone (AMH) in diagnosing and managing reproductive disorders in pediatric patients requires thorough knowledge on normative values according to age and gender. We provide age- and sex-specific reference ranges for the Immunotech assay and conversion factors for the DSL and Generation II assays. With this tool in hand, the pediatrician can use serum concentrations of AMH when determining the presence of testicular tissue in patients with bilaterally absent testes or more severe Disorders of Sex Development (DSD). Furthermore, AMH can be used as a marker of premature ovarian insufficiency (POI) in both Turner Syndrome patients and in girls with cancer after treatment with alkylating gonadotoxic agents. Lastly, its usefulness has been proposed in the diagnosis of polycystic ovarian syndrome (PCOS) and ovarian granulosa cell tumors and in the evaluation of patients with hypogonadotropic hypogonadism.

Anti-müllerian hormone: a valuable addition to the toolbox of the pediatric endocrinologist

Anti-Müllerian hormone (AMH), secreted by immature Sertoli cells, provokes the regression of male fetal Müllerian ducts. FSH stimulates AMH production; during puberty, AMH is downregulated by intratesticular testosterone and meiotic germ cells. In boys, AMH determination is useful in the clinical setting. Serum AMH, which is low in infants with congenital central hypogonadism, increases with FSH treatment. AMH is also low in patients with primary hypogonadism, for instance in Down syndrome, from early postnatal life and in Klinefelter syndrome from midpuberty. In boys with nonpalpable gonads, AMH determination, without the need for a stimulation test, is useful to distinguish between bilaterally abdominal gonads and anorchism. In patients with disorders of sex development (DSD), serum AMH determination helps as a first line test to orientate the etiologic diagnosis: low AMH is indicative of dysgenetic DSD whereas normal AMH is suggestive of androgen synthesis or action defects. Finally, in patients with persistent Müllerian duct syndrome (PMDS), undetectable serum AMH drives the genetic search to mutations in the AMH gene, whereas normal or high AMH is indicative of an end organ defect due to AMH receptor gene defects.

Circulating antimüllerian hormone levels in boys decline during early puberty and correlate with inhibin B

OBJECTIVE

To investigate peripheral levels of inhibin B and antimüllerian hormone (AMH) in boys during peripuberty and in patients with congenital hypogonadotropic hypogonadism (HH).

DESIGN

Randomized, placebo-controlled trial (peripubertal boys); and cross-sectional clinical study (males with HH).

SETTING

University central hospital.

PATIENT(S)

Twenty-eight peripubertal boys with idiopathic short stature (ISS), 19 males with Kallmann syndrome.

INTERVENTION(S)

Letrozole (2.5 mg/day) or placebo in boys with ISS for 2 years.

MAIN OUTCOME MEASURE(S)

Longitudinal follow-up observation of serum AMH and its relationship with inhibin B during early puberty and the influence of high (letrozole-treated boys) and low (males with HH) gonadotropin exposure on circulating AMH.

RESULT(S)

In boys with ISS receiving placebo, the decrease in AMH levels and the increase in inhibin B levels were correlated. The serum AMH level had already declined before a clinically significant increase in testis volume or serum testosterone occurred. Letrozole did not appear to modulate the decline in AMH. The AMH levels were lower in boys and young adults with Kallmann syndrome and prepubertal testes (mean: 20.9 ± 4.7 ng/mL, n = 6) as compared with prepubertal ISS boys (102.3 ± 11.9 ng/mL).

CONCLUSION(S)

The gonadotropin-mediated early pubertal increase in inhibin B is tightly coupled to decrease in AMH levels and may reflect androgen-mediated differentiation of Sertoli cells. Profound gonadotropin deficiency is associated with low AMH levels, suggesting impaired development of the Sertoli cell population.

New perspectives in the diagnosis of pediatric male hypogonadism: the importance of AMH as a Sertoli cell marker

Sertoli cells are the most active cell population in the testis during infancy and childhood. In these periods of life, hypogonadism can only be evidenced without stimulation tests, if Sertoli cell function is assessed. AMH is a useful marker of prepubertal Sertoli cell activity and number. Serum AMH is high from fetal life until mid-puberty. Testicular AMH production increases in response to FSH and is potently inhibited by androgens. Serum AMH is undetectable in anorchidic patients. In primary or central hypogonadism affecting the whole gonad and established in fetal life or childhood, serum AMH is low. Conversely, when hypogonadism affects only Leydig cells (e.g. LHβ mutations, LH/CG receptor or steroidogenic enzyme defects), serum AMH is normal or high. In pubertal males with central hypogonadism, AMH is low for Tanner stage (reflecting lack of FSH stimulus), but high for the age (indicating lack of testosterone inhibitory effect). Treatment with FSH provokes an increase in serum AMH, whereas hCG administration increases testosterone levels, which downregulate AMH. In conclusion, assessment of serum AMH is helpful to evaluate gonadal function, without the need for stimulation tests, and guides etiological diagnosis of pediatric male hypogonadism. Furthermore, serum AMH is an excellent marker of FSH and androgen action on the testis.

Clinical, biological and genetic analysis of anorchia in 26 boys

Background

Anorchia is defined as the absence of testes in a 46,XY individual with a male phenotype. The cause is unknown.

Methods

We evaluated the clinical and biological presentation, and family histories of 26 boys with anorchia, and sequenced their SRY, NR5A1, INSL3, MAMLD1 genes and the T222P variant for LGR8.

Results

No patient had any associated congenital anomaly. At birth, testes were palpable bilaterally or unilaterally in 13 cases and not in 7; one patient presented with bilateral testicular torsion immediately after birth. The basal plasma concentrations of anti-Müllerian hormone (AMH, n = 15), inhibin B (n = 7) and testosterone (n = 19) were very low or undetectable in all the patients evaluated, as were the increases in testosterone after human chorionic gonadotropin (hCG, n = 12). The basal plasma concentrations of follicle stimulating hormone (FSH) were increased in 20/25, as was that of luteinising hormone in 10/22 cases. Family members of 7/26 cases had histories of primary ovarian failure in the mother (n = 2), or sister 46,XX, together with fetal malformations of the only boy with microphallus and secondary foot edema (n = 1), secondary infertility in the father (n = 2), or cryptorchidism in first cousins (n = 2). The sequences of all the genes studied were normal.

Conclusion

Undetectable plasma concentrations of AMH and inhibin B and an elevated plasma FSH, together with 46,XY complement are sufficient for diagnosis of anorchia. The hCG test is unnecessary. NR5A1 and other genes implicated in gonadal development and testicle descent were not mutated, which suggests that other genes involved in these developments contribute to the phenotypes.

Consensus in Guidelines for Evaluation of DSD by the Texas Children's Hospital Multidisciplinary Gender Medicine Team

The Gender Medicine Team (GMT), comprised of members with expertise in endocrinology, ethics, genetics, gynecology, pediatric surgery, psychology, and urology, at Texas Children's Hospital and Baylor College of Medicine formed a task force to formulate a consensus statement on practice guidelines for managing disorders of sexual differentiation (DSD) and for making sex assignments. The GMT task force reviewed published evidence and incorporated findings from clinical experience. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess the quality of evidence presented in the literature for establishing evidence-based guidelines. The task force presents a consensus statement regarding specific diagnostic and therapeutic issues in the management of individuals who present with DSD. The consensus statement includes recommendations for (1) laboratory workup, (2) acute management, (3) sex assignment in an ethical framework that includes education and involvement of the parents, and (4) surgical management.

Postnatal testicular regression mircopenis and microcephaly: conformation of a new syndrome?

Testicular regression may develop at various phases of the intrauterine period and the clinical findings vary depending on the timing of the intrauterine phase. On the other hand, postnatal regression of the testicles is rare and few cases have been reported in the literature. Our patient presented with undescended testicles, micropenis, flat scrotum and microcephaly. The patient's levels of basal luteinizing hormone (LH) were low/normal and follicle stimulating hormone (FSH) was high. No response was obtained in the human chorionic gonadotropin (HCG) stimulation test. The levels of inhibin B and anti Mullerian hormone (AMH) were found to be low. Penile growth response to intramuscular testosterone injections was 2.5 cm. Testicles were visualized bilaterally in inguinal canal by ultrasound examination initially but by 2 years of age no testicular tissue was observed during inguinal exploration. In conclusion we recognized postnatal testicular regression in our patient that had started in the intrauterine period and persisted into infancy. The genital system anomalies, microcephaly and motor retardation in our patient confirm the hypothesis of Parisi et al. of a novel condition of postnatal regression and micropenis.

Transverse testicular ectopia: correlation of embryology with laparoscopic findings

Two patients with unilateral transverse testicular ectopia (TTE) without the persistence of Mullerian duct structures are described. Each presented with unilateral impalpable testis and a contralateral inguinal hernia. The diagnosis of unilateral TTE was made during laparoscopic evaluation for undescended testis. The first patient had unilateral TTE on the right side and the second on the left. In both patients, a long thin band resembling the round ligament of the uterus was seen extending from the region of the internal inguinal ring (IIR) on the side of the undescended testis to the opposite inguinal canal. In both patients, there was no patent processus vaginalis on the side of the undescended testis and on the contralateral side the internal rings were widely patent with large hernial sacs. In the second patient, the right vas was seen extending from the right IIR towards the right side of the pelvis. The right vas showed a short segment of discontinuity at the level of the right IIR while its proximal end extended into the left inguinal canal in close relation to the right spermatic vessels. The vasal anomaly was probably ischemic in origin, resulting from excessive mobility of the ectopic testis and its vas in TTE. Correlation of the current hypotheses on the embryology of TTE with the above mentioned laparoscopic findings is discussed.

Anti-Müllerian hormone in disorders of sex determination and differentiation

Masculinisation of internal and external genitalia during foetal development depends on the existence of two discrete testicular hormones: Leydig cell-secreted testosterone drives the differentiation of the Wolffian ducts, the urogenital sinus and the external genitalia, whereas Sertoli cell-produced anti-Müllerian hormone (AMH) provokes the regression of Müllerian ducts. The absence of AMH action in early foetal life results in the formation of the Fallopian tubes, the uterus and the upper third of the vagina. In 46,XY foetuses, lack of AMH may result from testicular dysgenesis affecting both Leydig and Sertoli cell populations: in this case persistence of Müllerian remnants is associated with ambiguous or female external genitalia. Alternatively, defective AMH action may result from mutations of the genes encoding for AMH or its receptor: in this condition known as Persistent Müllerian Duct Syndrome, testosterone production is normal and external genitalia are normally virilised. Finally, AMH may be normally secreted in intersex patients with defects restricted to androgen synthesis or action, resulting in patients with female or ambiguous external genitalia with no Müllerian derivatives.

The effects of orchiopexy on serum anti-Müllerian hormone levels in unilateral cryptorchid infants

BACKGROUND/PURPOSE

In males, serum anti-Müllerian hormone (AMH) reflects Sertoli cell function and provides an estimate of seminiferous tubular integrity. It has been suggested that comparison of AMH levels before and after surgery could be useful to determine effectiveness of the treatment. In this study, we determined the serum AMH levels in infants with unilateral cryptorchidism before and after orchiopexy procedure and compared these data with the AMH values in age-matched controls.

METHODS

The study population was 20 cryptorchid children with unilateral palpable testes who underwent orchiopexy as a cryptorchid group, and 20 healthy children who underwent circumcision as a control group. All children are 12 months of age. Serum AMH levels were measured at just before surgery (at 12 month old) and 6 months after surgery (at 18 month old).

RESULTS AND CONCLUSIONS

All undescended testes were found to be normal in size and in the superficial inguinal pouch or subcutaneous region of the groin at surgery. With regard to the preoperative serum AMH levels, there was a significant difference between the cryptorchid and the control groups (40.04 +/- 4.97 ng/ml versus 53.46 +/- 7.51 ng/ml) (P < 0.05). Similarly, the postoperative serum AMH levels were lower in cryptorchid children than in controls (39.27 +/- 4.58 ng/ml versus 52.79 +/- 6.27 ng/ml) (P < 0.05). In cryptorchid children, serum AMH levels measured at 6 months after orchiopexy were similar with preoperative basal levels (40.04 +/- 4.97 ng/ml versus 39.27 +/- 4.58 ng/ml) (P > 0.05). AMH levels in children with unilateral palpable undescended testes remain unchanged 6 months after orchiopexy performed at 1 year of age. This is the first report in literature regarding the effect of orchiopexy on the serum AMH levels.