Infertility in Cryptorchidism Is Linked to the Stage of Germ Cell Development at Orchidopexy

Comparison of conventional Doppler imaging techniques and superb microvascular imaging in determination of vascularization in undescended testes

Aim

Our aim was to gain an idea about testicular injury by comparing the reduced volume, which is one of the indirect indicators of testicular damage in undescended testes, and by evaluating the reduced microvascular blood flow by superb microvascular imaging, and also to determine whether superb microvascular imaging modes could detect microvascular blood flow in more detail in the decreased volume of undescended testes.

Material and methods

We compared testicular blood flow in undescended testes via conventional Doppler imaging, color superb microvascular imaging, and monochrome superb microvascular imaging techniques with contralateral normally located testis and normal control group. Each sample of testicular tissue was evaluated using a qualitative method. Spot color encoding and linear flow color encoding counts determined in testicular parenchyma were counted separately and expressed as numerical data. The localization of the examined testes in the grayscale was noted (proximal inguinal canal, medial inguinal canal, distal inguinal canal, and scrotal). The volume of undescended testes was calculated automatically via a formula for volume.

Results

Monochrome superb microvascular imaging is significantly superior in visualizing the vascularity of undescended testes compared with color Doppler, power Doppler and color superb microvascular imaging (p = 0.001). Also, undescended testes have a significantly lower blood flow compared with contralateral normal testes (p = 0.001). The volume of undescended testes was significantly lower than the contralateral normal testes.

Conclusions

The volume, structure and blood flow are indirect signs of testicular damage in undescended testes. Monochrome superb microvascular imaging can detect vascularity in undescended testes better than the conventional Doppler imaging technique and color superb microvascular imaging. Based on our findings, we can report that monochrome superb microvascular imaging can be used to evaluate testicular injury and vascularity of undescended testes.

Management Outcomes in Males With Hypogonadotropic Hypogonadism Treated With Gonadotropins

Background Hypogonadotropic hypogonadism is an important cause of male infertility and loss of secondary sexual characteristics. Gonadotropin replacement is mandatory for sexual function, bone health, and normal psychological status. This study is to compare the effectiveness of different gonadotropin therapy modalities in the management of male hypogonadism. Methods A randomized open-label prospective study of 51 patients attended the Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC) with hypogonadotropic hypogonadism, divided randomly into three groups. The first group was treated with human chorionic gonadotropin (hCG) alone, the second group was treated with a combination of both hCG and human menopausal gonadotropin (HMG), while the third group started with hCG alone then followed by combination therapy after six months. Results All modalities of therapy result in a significant increase in mean testicular volume although no clinically significant difference between the groups, but the combination group had the highest increment. The increment in serum testosterone level was statistically significant among the different groups of treatment (p-value < 0.0001). When comparing groups, a higher mean maximum testosterone level (710.4±102.7 ng/dL) was obtained with the combination group followed by the sequential group, with mean maximum testosterone levels (636.0±68.6 ng/dL) (p-value = 0.031). Factors negatively affecting testosterone level include BMI > 30 kg/m², initial testicular volume < 5 mL, and duration of therapy < 13 months. Conclusions Induction of puberty using recombinant hCG alone is sufficient to induce secondary sexual characteristics, while for fertility issues combination from the start or sequential therapy has better for spermatogenesis. There was no effect of prior exogenous testosterone treatment on final spermatogenesis.

Risk factors on testicular function in adolescents

PURPOSE

Adolescence represents an important window for gonadal development. The aim of this review is to carry out a critical excursus of the most recent literature on endogenous and exogenous risk factors related to testicular function, focusing the research on adolescence period.

METHODS

A comprehensive literature search within PubMed was performed to provide a summary of currently available evidence regarding the impact on adolescence of varicocele, cryptorchidism, cancer, diabetes, lifestyle factors, endocrine disruptors, obesity and sexually transmitted diseases. We focused on human studies that evaluated a possible impact of these factors on puberty timing and their effects on andrological health.

RESULTS

Evidence collected seems to suggest that andrological health in adolescence may be impaired by several factors, as varicocele, cryptorchidism, and childhood cancer. Despite an early diagnosis and treatment, many adolescents might still have symptoms and sign of a testicular dysfunction in their adult life and at the current time it is not possible to predict which of them will experience andrological problems. Lifestyle factors might have a role in these discrepancies. Most studies point out towards a correlation between obesity, insulin resistance, alcohol, smoking, use of illegal drugs and testicular function in pubertal boys. Also, endocrine disruptors and sexually transmitted diseases might contribute to impair reproductive health, but more studies in adolescents are needed.

CONCLUSION

According to currently available evidence, there is an emerging global adverse trend of high-risk and unhealthy behaviors in male adolescents. A significant proportion of young men with unsuspected and undiagnosed andrological disorders engage in behaviors that could impair testicular development and function, with an increased risk for later male infertility and/or hypogonadism during the adult life. Therefore, adolescence should be considered a key time for intervention and prevention of later andrological diseases.

Postnatal germ cell development in cryptorchid boys

Cryptorchidism is associated with infertility in adulthood. Early orchiopexy is suggested to reduce the risk. Information is lacking on the potential link between infant germ cell maturation and the risk of future infertility. The objective of the study was to evaluate age-related germ cell development in cryptorchidism. Immunostaining for markers of germ cell development (octamer-binding transcription factor 3/4 [OCT3/4], placental alkaline phosphatase [PLAP], KIT proto-oncogene [C-KIT], podoplanin [D2-40], Lin-28 homolog A [LIN28], and G antigen 7 [GAGE-7]) was performed in testicular biopsies from 40 cryptorchid boys aged 4-35 months. Germ cell numbers and distributions were evaluated in cross sections of seminiferous tubules, with and without immunostaining. OCT3/4, D2-40, and LIN28 were generally expressed in the early stages of germ cell development, as shown by positive expression in germ cells in the central region of seminiferous tubules. In contrast, PLAP and GAGE-7 were expressed in both central and peripheral parts of the tubules in the early stages of development and expressed mainly in a peripheral position with advancing age. Germ cell maturation was delayed in this study population as compared with that observed in our previous study on germ cell markers in a healthy population. The number of GAGE-7-positive germ cells per tubular cross section obtained by immunostaining was significantly higher than that obtained by standard hematoxylin and eosin staining. Double immunostaining revealed heterogeneity in germ cell development in cryptorchid testes. These results shed light on the pathophysiology of germ cell development in boys with cryptorchidism.

Male infertility due to testicular disorders

CONTEXT

Male infertility is defined as the inability to conceive following 1 year of regular unprotected intercourse. It is the causative factor in 50% of couples and a leading indication for assisted reproductive techniques (ART). Testicular failure is the most common cause of male infertility, yet the least studied to date.

EVIDENCE ACQUISITION

The review is an evidence-based summary of male infertility due to testicular failure with a focus on etiology, clinical assessment, and current management approaches. PubMed-searched articles and relevant clinical guidelines were reviewed in detail.

EVIDENCE SYNTHESIS/RESULTS

Spermatogenesis is under multiple levels of regulation and novel molecular diagnostic tests of sperm function (reactive oxidative species and DNA fragmentation) have since been developed, and albeit currently remain as research tools. Several genetic, environmental, and lifestyle factors provoking testicular failure have been elucidated during the last decade; nevertheless, 40% of cases are idiopathic, with novel monogenic genes linked in the etiopathogenesis. Microsurgical testicular sperm extraction (micro-TESE) and hormonal stimulation with gonadotropins, selective estrogen receptor modulators, and aromatase inhibitors are recently developed therapeutic approaches for men with the most severe form of testicular failure, nonobstructive azoospermia. However, high-quality clinical trials data is currently lacking.

CONCLUSIONS

Male infertility due to testicular failure has traditionally been viewed as unmodifiable. In the absence of effective pharmacological therapies, delivery of lifestyle advice is a potentially important treatment option. Future research efforts are needed to determine unidentified factors causative in "idiopathic" male infertility and long-term follow-up studies of babies conceived through ART.

How boys and testicles wander to surgery: a nationwide cohort study of surgical delay in Sweden

BACKGROUND

Early orchidopexy is recommended for cryptorchidism and the surgery is increasingly centralised. The objectives were to determine the incidence, risk factors and if distance to treating hospital impacted on timely treatment of cryptorchidism.

METHODS

In this observational study, all boys born in Sweden from 2001 to 2014 were followed in national registers to determine the incidence of cryptorchidism by levels of birth-related risk factors and social determinants. Travel time to hospital was used as the primary exposure in multivariable survival analysis, with age at surgery as main outcome.

RESULTS

Of 748 678 boys at risk for cryptorchidism, 7351 were treated and evaluated for timing of surgery (cumulative childhood incidence 1.4%, 95% CI 1.3% to 1.5%). The incidence was clearly associated with prematurity and overdue pregnancy (HR for <32 weeks 2.77 (95% CI 2.39 to 3.21); 32-36 weeks HR 1.36 (95% CI 1.24 to 1.49); >41 weeks HR 1.19 (95% CI 1.10 to 1.29)), low birth weight (<1000 g HR 3.94 (95% CI 3.15 to 4.92); 1000-1499 g HR 3.70 (95% CI 3.07 to 4.46); 1500-2500 g HR 1.69 (95% CI 1.52 to 1.88)) and intrauterine growth restriction (small for gestational age HR 2.38 (95% CI 2.14 to 2.65); large for gestational age HR 1.26 (95% CI 1.13 to 1.42)), but not with smoking or maternal age. Each 30 min increase in travel time was associated with a reduced probability of timely treatment (HR for being treated by age 3 adjusted for risk factors and socioeconomic determinants: 0.91 (95% CI 0.88 to 0.95)). Lower income and financial support were also associated with treatment delays (adjusted HR for lowest income quintile 0.82 (95% CI 0.72 to 0.93) and for families with financial support 0.85 (95% CI 0.73 to 0.97)).

CONCLUSIONS

Travel distance to treating hospital was associated with delayed treatment. 'Not all those who wander are lost', but these findings suggest a trade-off between centralisation benefits and barriers of geography also in elective paediatric surgery.

Abnormal histology in testis from prepubertal boys with monorchidism

BACKGROUND

Little is known about the histology of contralateral descended testes in boys with unilaterally absent testis. We investigated whether absence of one testis is associated with abnormal tissue architecture of the solitary contralaterally descended testis.

DESIGN SETTING AND PATIENTS

For this retrospective study, we examined the results of biopsies of the contralateral descended testis in 43 boys with monorchidism. Data from 26 control testes from boys of matching ages were selected from results published in 1977 and 2009. During surgery, any nubbins were removed. In each case, the scrotal testis was biopsied, and the testis fixed by subdartos pouch or suture.

RESULTS

Of the 43 affected boys, 23 had normal testicular histology in the contralateral descended testis, whereas 20 (46%) had abnormal histology. Eight of the abnormal biopsies matched the criteria for high infertility risk. Samples from three boys in this latter group revealed a Sertoli-cell-only phenotype. Immunohistochemical assays were positive for steroidogenic acute regulatory (STAR) protein in Leydig cells and spermatogonia. STAR expression was stronger in the monorchid group with normal testicular histology.

CONCLUSIONS

Almost half of the patients with unilateral absent testis were at risk for subfertility or infertility. Our results emphasize the need for testicular biopsy of the solitary testis in boys with monorchidism to appropriately assess infertility risk.

Clinical and socioeconomic factors associated with delayed orchidopexy in cryptorchid boys in China: a retrospective study of 2423 cases

We investigated the associations of clinical and socioeconomic factors with delayed orchidopexy for cryptorchidism in China. A retrospective study was conducted on cryptorchid boys who underwent orchidopexy at Children's Hospital at Chongqing Medical University in China from January 2012 to December 2017. Of 2423 patients, 410 (16.9%) received timely repair by 18 months of age, beyond which surgery was considered delayed. Univariate analysis suggested that the laterality of cryptorchidism (P = 0.001), comorbidities including inguinal hernia/scrotal hydrocele (P < 0.001) or urinary tract disease (P = 0.016), and whether patients lived in a poverty county (P < 0.001) could influence whether orchidopexy was timely or delayed. Logistic regression analysis suggested that the following factors were associated with delayed repair: unilateral rather than bilateral cryptorchidism (odds ratio [OR] = 1.752, P < 0.001), absence of inguinal hernia or hydrocele (OR = 2.027, P = 0.019), absence of urinary tract disease (OR = 3.712, P < 0.001), and living in a poverty county (OR = 2.005, P < 0.001). The duration of postoperative hospital stay and hospital costs increased with the patient's age at the time of surgery.

["Uncomplicated" inguinal testis : How practicable are the guidelines?]

It has been known for more than 20 years that early treatment of maldescended testicles can have a positive effect on fertility and a negative effect on the development of tumors. In certain circumstances, hormone therapy is still recommended in German-speaking countries. However, its benefit is still controversially discussed. Therapy is usually initiated by the pediatrician, who is usually the first to detect undescended testicles. Since therapy may involve early hormone therapy as well as surgery, acceptance among pediatricians and also the parents may be reduced. The question also arises as to how far the implementation is practicable. In patients with nonpalpable testis, there are many controversies concerning the value of ultrasound investigations. In the following two case studies, the treatment decisions for undescended testes in infancy are exemplified. Furthermore, the available evidence from the literature and guidelines is presented to provide assistance for daily routine care and to critically discuss potential fields of application and limitations of existing guidelines.

The effects of tobacco consumption on paternity rates of adults with a history of cryptorchidism

OBJECTIVE

To determine the effect of tobacco consumption on paternity rates in men with a history of cryptorchidism. To compare the paternity rates between formerly unilateral, bilateral cryptorchid smokers, and nonsmokers.

METHODS

A retrospective cohort study of 153 men who had undergone orchiopexy between 1961 and 1985 at the Miguel Servet University Hospital (116 unilateral and 37 bilateral) and a control group of 100 men were evaluated by review of medical records and a questionnaire.

RESULTS

A total of 197 men filled the questionnaire (76.7%). There was no difference in paternity rates between smokers compared to nonsmokers (P = 0.21). In the unilateral cryptorchid men (ULC) group, there is no difference in paternity rates when compared with the controls (P = 0.079) or when comparing ULC smokers to ULC nonsmokers (P = 0.35). In the bilateral cryptorchid men (BLC) group, there is no difference in paternity rates when compared to controls (P = 0.075) or when comparing BLC smokers to BLC nonsmokers (P = 0.36). When comparing according to consumption, there is no difference between mild, moderate or heavy smoker cases and controls.

CONCLUSION

There is no difference in paternity rates between men with a history of cryptorchidism that consume tobacco compared to nonsmokers or controls. More studies are needed to determine the impact of tobacco consumption in formerly cryptorchid men.

Development and Disease-Dependent Dynamics of Spermatogonial Subpopulations in Human Testicular Tissues

Cancer therapy and conditioning treatments of non-malignant diseases affect spermatogonial function and may lead to male infertility. Data on the molecular properties of spermatogonia and the influence of disease and/or treatment on spermatogonial subpopulations remain limited. Here, we assessed if the density and percentage of spermatogonial subpopulation changes during development (n = 13) and due to disease and/or treatment (n = 18) in tissues stored in fertility preservation programs, using markers for spermatogonia (MAGEA4), undifferentiated spermatogonia (UTF1), proliferation (PCNA), and global DNA methylation (5mC). Throughout normal prepubertal testicular development, only the density of 5mC-positive spermatogonia significantly increased with age. In comparison, patients affected by disease and/or treatment showed a reduced density of UTF1-, PCNA- and 5mC-positive spermatogonia, whereas the percentage of spermatogonial subpopulations remained unchanged. As an exception, sickle cell disease patients treated with hydroxyurea displayed a reduction in both density and percentage of 5mC- positive spermatogonia. Our results demonstrate that, in general, a reduction in spermatogonial density does not alter the percentages of undifferentiated and proliferating spermatogonia, nor the establishment of global methylation. However, in sickle cell disease patients’, establishment of spermatogonial DNA methylation is impaired, which may be of importance for the potential use of this tissues in fertility preservation programs.

Testicular expression of long non-coding RNAs is affected by curative GnRHa treatment of cryptorchidism

Background

Cryptorchidism is a frequent endocrinopathy in boys that has been associated with an increased risk of developing testicular cancer and infertility. The condition is curable by combined surgery and hormonal treatment during early pre-pubertal stages using gonadotropin releasing hormone agonist (GnRHa). However, whether the treatment also alters the expression of testicular long non-coding RNAs (lncRNAs) is unknown. To gain insight into the effect of GnRHa on testicular lncRNA levels, we re-analyzed an expression dataset generated from testicular biopsies obtained during orchidopexy for bilateral cryptorchidism.

Results

We identified EGFR-AS1, Linc-ROR, LINC00221, LINC00261, LINC00282, LINC00293, LINC00303, LINC00898, LINC00994, LINC01121, LINC01553, and MTOR-AS1 as potentially relevant for the stimulation of cell proliferation mediated by GnRHa based on their direct or indirect association with rapidly dividing cells in normal and pathological tissues. Surgery alone failed to alter the expression of these transcripts.

Conclusion

Given that lncRNAs can cooperate with chromatin-modifying enzymes to promote epigenetic regulation of genes, GnRHa treatment may act as a surrogate for mini-puberty by triggering the differentiation of Ad spermatogonia via lncRNA-mediated epigenetic effects. Our work provides additional molecular evidence that infertility and azoospermia in cryptorchidism, resulting from defective mini-puberty cannot be cured with successful orchidopexy alone.

Fertility after the Operation of Cryptorchism in Childhood

Cryptorchism is a congenital anomaly of male genitalia, and is defined as a disorder of lowering testicles into the scrotum. In our study, the quality of sperm and fertility of men who were operated from unilateral or bilateral cryptorchism in childhood were analyzed. According to the age in which they were operated, patients were classified into different time groups, subjected to clinical examination and sperm analysis. A normal sperm count was found: 36.9% of the total number of patients operated from unilateral to bilateral cryptorchism. The highest percentage of normal sperm counts was 73.97%: the data which was found in the group that was operated from one-sided cryptorchism to the end of the second year of life. Regardless of the age of the cryptorchism operation, it is possible to expect a disorder of spermatogenesis.

Plasma concentration of MMP-1 and MMP-2 in boys with cryptorchidism and its lack of correlation with INSL3 and inhibin B

The matrix metalloproteinases are enzymes capable of remodeling of extracellular matrix, and modulate the behavior of cells. Maturation of gubernaculum and spermatogenesis demand proper equilibrium of metalloproteinases and their inhibitors. The aim of this survey was to investigate the levels of matrix metalloproteinase type 1 (MMP-1) and matrix metalloproteinase type 2 (MMP-2) in the plasma of children with unilateral cryptorchidism along with levels of Insulin-like Peptide 3 (INSL3) and inhibin B. INSL3 have a role in gubernaculum development. Inhibin B is produced by Sertoli cells, and its levels reflect the status of the testis germinative epithelium. Fifty boys with an undescended testicle, aged 1-4 years (median = 2.4 years) were enrolled into the study. Fifty boys with inguinal hernia aged 1-4 years, served as controls (median age = 2.1 years). Investigators assessed the MMP-1 and MMP-2 concentrations using Surface Plasmon Resonance Imaging. The levels of INSL-3 and inhibin B were assessed using commercial enzyme-linked immunosorbent assay ELISA. The median concentration of MMP-1 and MMP-2 in the blood plasma of patients with unilateral cryptorchidism, was nearly 2-folds higher than in controls. The great area under the ROC curve with the cut off value of 0.865 for MMP-1, and 0.819 for MMP-2, indicates the high clinical sensitivity and specificity of the test of plasma levels of MMP-1 and MMP-2 for boys with cryptorchidism. The increased plasma levels of MMP-1 and MMP-2, probably reflect the level of apoptosis of the germ cells in undescended testicles, in response to the heat stress during the period of prepubertal testis development. In the group of cryptorchid boys, we found slightly lower concentrations of INSL3, without statistical significance and without correlation with MMP-1 and MMP-2 levels. There were no significant differences in the levels of inhibin B in the group of boys with cryptorchidism and boys with inguinal hernia and it also did not correlate with MMP-1 and MMP-2 concentrations.

Genes located in Y-chromosomal regions important for male fertility show altered transcript levels in cryptorchidism and respond to curative hormone treatment

Background

Undescended (cryptorchid) testes in patients with defective mini-puberty and low testosterone levels contain gonocytes that fail to differentiate normally, which impairs the development of Ad spermatogonia and ultimately leads to adult infertility. Treatment with the gonadotropin-releasing hormone agonist GnRHa increases luteinizing hormone and testosterone and rescues fertility in the majority of pathological cryptorchid testes. Several Y-chromosomal genes in the male-specific Y region (MSY) are essential for spermatogenesis, testis development and function, and are associated with azoospermia, infertility and cryptorchidism. In this study, we analyzed the expression of MSY genes in testes with Ad spermatogonia (low infertility risk patients) as compared to testes lacking Ad spermatogonia (high infertility risk) before and after curative GnRHa treatment, and in correlation to their location on the Y-chromosome.

Results

Twenty genes that are up- or down-regulated in the Ad- group are in the X-degenerate or the ampliconic region, respectively. GnRHa treatment increases mRNA levels of 14 genes in the ampliconic region and decreases mRNA levels of 10 genes in the X-degenerate region.

Conclusion

Our findings implicate Y-chromosomal genes, including USP9Y, UTY, TXLNGY, RBMY1B, RBMY1E, RBMY1J and TSPY4, some of which are known to be important for spermatogenesis, in the curative hormonal treatment of cryptorchidism-induced infertility.

Is Hormonal Treatment of Congenital Undescended Testes Justified? A Debate

Abnormal germ cell development in cryptorchidism is not a result of a congenital dysgenesis but is preceded by a hormone imbalance and perturbation in germ cell-specific gene expression during abrogated mini-puberty. Adequate treatment with low doses of GnRHa enables 86% of men to achieve a normal sperm count and, most importantly, prevent development of azoospermia. GnRHa treatment induces a significant transcriptional response, including protein coding genes involved in pituitary development, the hypothalamic-pituitary-gonadal axis, and testosterone synthesis. Furthermore, hormonal treatment to achieve epididymo-testicular descent as a first choice of treatment of cryptorchidism has a long tradition in Europe. It eliminates the necessity of subsequent surgery. Moreover, in the cases of non-responders it facilitates orchidopexy and contributes considerably to a reduced incidence of unilateral and the more serious bilateral complete post-surgical testicular atrophy.

PRDM Histone Methyltransferase mRNA Levels Increase in Response to Curative Hormone Treatment for Cryptorchidism-Dependent Male Infertility

There is a correlation between cryptorchidism and an increased risk of testicular cancer and infertility. During orchidopexy, testicular biopsies are performed to confirm the presence of type A dark (Ad) spermatogonia, which are a marker for low infertility risk (LIR). The Ad spermatogonia are absent in high infertility risk (HIR) patients, who are treated with a gonadotropin-releasing hormone agonist (GnRHa) to significantly lower the risk of infertility. Despite its prevalence, little is known about the molecular events involved in cryptorchidism. Previously, we compared the transcriptomes of LIR versus HIR patients treated with and without hormones. Here, we interpreted data regarding members of the positive regulatory domain-containing (PRDM) family; some of which encoded histone methyltransferases that are important for reproduction. We found there were lower levels of PRDM1, PRDM6, PRDM9, PRDM13, and PRDM14 mRNA in the testes of HIR patients compared with LIR patients, and that PRDM7, PRDM9, PRDM12, and PRDM16 were significantly induced after GnRHa treatment. Furthermore, we observed PRDM9 protein staining in the cytoplasm of germ cells in the testes from LIR and HIR patients, indicating that the mRNA and protein levels corresponded. This result indicated that the curative hormonal therapy for cryptorchidism involved conserved chromatin modification enzymes.

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.

DMRTC2, PAX7, BRACHYURY/T and TERT Are Implicated in Male Germ Cell Development Following Curative Hormone Treatment for Cryptorchidism-Induced Infertility

Defective mini-puberty results in insufficient testosterone secretion that impairs the differentiation of gonocytes into dark-type (Ad) spermatogonia. The differentiation of gonocytes into Ad spermatogonia can be induced by administration of the gonadotropin-releasing hormone agonist, GnRHa (Buserelin, INN)). Nothing is known about the mechanism that underlies successful GnRHa treatment in the germ cells. Using RNA-sequencing of testicular biopsies, we recently examined RNA profiles of testes with and without GnRHa treatment. Here, we focused on the expression patterns of known gene markers for gonocytes and spermatogonia, and found that DMRTC2, PAX7, BRACHYURY/T, and TERT were associated with defective mini-puberty and were responsive to GnRHa. These results indicate novel testosterone-dependent genes and provide valuable insight into the transcriptional response to both defective mini-puberty and curative GnRHa treatment, which prevents infertility in man with one or both undescended (cryptorchid) testes.

Association of Levels of Serum Inhibin B and Follicle-stimulating Hormone with Testicular Vascularity, Volume, and Echotexture in Children with Undescended Testes

Aims:

The aim of our study was to assess the association between reproductive hormones (inhibin B [inh B], follicle-stimulating hormone [FSH]) with testicular volume, echogenicity, and blood flow (resistive index [RI]) in children with undescended testis (UDT).

Settings and Design:

This was a prospective study of 1-year study duration.

Materials and Methods:

A total of 33 patients (16 unilateral and 17 bilateral) UDTs aged 5–12 years with palpable UDT were included in the study. Morning fasting blood samples were taken for estimation of serum inh B and FSH as well as inh B/FSH ratio. Testicular ultrasound was done to compute testicular volume, testicular echogenicity, and testicular vascularity in terms of RI.

Results:

The mean age of patients enrolled in the study was 8.29 years for unilateral UDT and 7.97 years in bilateral UDT and it was comparable. The study groups were further subdivided into two age-wise subgroups school goers (5–8 years) and prepubertal (9–12 years). The values of inh B, FSH, and inh B/FSH ratios as well as mean testicular volume were comparable between both groups and subgroups. Overall mean testicular volume had a positive correlation with FSH, inh B, and inh B/FSH, but statistical significance was reached only for inh B (P < 0.001) in children with both unilateral and bilateral UDT. Apart from five patients with hypoechogenicity within the testis, all remaining testes were of homogenous echotexture with no instances of irregular echogenicity or tumor. Children with RI >0.6 were separately studied. The incidence of high RI (>0.6) was also comparable in unilateral or bilateral disease. These subjects had unfavorable biochemical parameters in terms of low inh B levels and high FSH levels.

Conclusions:

Our findings hint to the fact that palpable UDT forms a homogenous group, whether unilateral or bilateral, whereas impalpable testes may form a separate category and need further studies to substantiate this hypothesis.

[Undescended testis: current treatment guidelines]

BACKGROUND

Cryptorchidism is the most common genital malformation in male newborns. In recent years, guidelines concerning diagnosis and therapy have undergone considerable evolution with the implementation of recent knowledge in pathophysiology, diagnosis, and therapy.

OBJECTIVES

The aim of this publication is to provide an overview of the current national and international guideline recommendations concerning diagnosis and treatment of cryptorchidism. Critical points are discussed in light of current scientific literature.

MATERIALS AND METHODS

The current guidelines of the European Association of Urology (EAU)/European Society for Pediatric Urology (ESPU), the American Association of Urology (AUA), the pediatric urologic task force of the Austrian Society of Urology (ÖGU), the international consultation on urological disease (ICUD) and the German Society of Urology (DGU)/German Association of Pediatric Surgery (DGKCh) have been analyzed concerning the most important aspects of treatment and diagnosis.

RESULTS

There is broad consensus concerning most steps and decisions for the treatment of cryptorchidism. However, some aspects of diagnostic imaging, the use of hormonal therapy, and surgical access in nonpalpable testis warrant further discussion and are the fields of considerable changes.

Gene Expression Changes Underlying Idiopathic Central Hypogonadism in Cryptorchidism with Defective Mini-Puberty

The whole genome RNA profiling of testicular biopsies by DNA strand-specific RNA sequencing was examined to determine a potential causative role of isolated congenital cryptorchidism in azoospermia and/or infertility in the context of our previously published GeneChip data. Cryptorchid patients, aged 7 months to 5 years and otherwise healthy, were enrolled in this prospective study. During surgery, testicular tissue biopsies were obtained for histological examination and RNA sequencing. Fifteen patients were selected based on the histological results and were divided into 2 groups. Seven were classified as belonging to the high infertility risk (HIR) and 8 to the low infertility risk (LIR) group. Cryptorchid boys in the HIR group lacked transformation of gonocytes into Ad spermatogonia due to impaired mini-puberty. This group of patients will be infertile despite successful surgery. The new important finding was a decreased PROK2, CHD7, FGFR1, and SPRY4 gene expression in the HIR group. Furthermore, identification of multiple differences in gene expression between HIR and LIR groups underscores the importance of an intact hypothalamic-pituitary-gonadal axis for fertility development. Our RNA profiling data strongly support the theory that in the HIR group of cryptorchid boys insufficient PROK2/CHD7/FGFR1/SPRY4 gene expression induces deficient LH secretion, resulting in impaired mini-puberty and infertility. We therefore recommend hormonal treatment for this cohort of cryptorchid boys with defective mini-puberty following a seemingly successful orchidopexy.

Prospective study of histological and endocrine parameters of gonadal function in boys with cryptorchidism

INTRODUCTION

A transient increase in gonadotropins and testosterone during mini-puberty causes gonocytes to differentiate into Ad spermatogonia, which establish male germ cell memory and male-specific DNA methylation pathways. Over half of patients with unilateral cryptorchidism and the majority of patients with bilateral cryptorchidism display an abnormal spermiogram, which indicates that unilateral cryptorchidism is a bilateral disease; therefore, it represents a serious andrological problem. The aim of this study was to evaluate relationships between hormonal parameters and testicular biopsy findings in boys with cryptorchidism.

METHOD

Seventy-one boys (median age 15 months; range 7-65 months) who underwent orchidopexy (24% had bilateral cryptorchidism) were tested for serum LH, FSH, and inhibin B. With ipsilateral testis biopsy histology, we determined the tubular fertility index (TFI), Ad spermatogonia counts, and Ad/tubular index (Ad/T). We compared age groups (<18 vs. >18 months old); groups with and without Ad spermatogonia; groups with unilateral and bilateral cryptorchidism; and extreme groups with high infertility risk (HIR; n = 12; TFI <0.2; Ad/T = 0) and low infertility risk (LIR; n = 9; TFI >0.9; Ad/T>0.02).

RESULTS

Of the specimens, 38% had no Ad spermatogonia. Age was significantly negatively correlated with TFI and Ad/T, but positively correlated with FSH. Median LH values were significantly higher in LIR than in HIR groups. Unilateral and bilateral cryptorchidism showed similar TFI, Ad/T, and hormone concentrations. The areas under ROC curves for FSH, LH, and inhibin B (0.66, 0.601, and 0.599, respectively) showed low diagnostic value for predicting HIR (no Ad spermatogonia).

CONCLUSION

Our observation of lower plasma LH levels in the group with the most pronounced testicular pathology was the opposite of what we would have expected if testicular pathological changes were caused by a primary gonadal defect. Therefore, low plasma LH levels in the HIR group confirmed the notion that this group of patients with cryptorchidism had hypogonadotropic hypogonadism. The estimated incidence of defective mini-puberty in boys with cryptorchidism could be as high as 50%. Testicular biopsies from boys with cryptorchidism lacked Ad spermatogonia. Fertility parameters worsened with age. Significantly lower basal LH in the HIR group indicated hypogonadotropic hypogonadism. Serum hormone levels could not predict histological biopsy findings.

Undescended testis - current trends and guidelines: a review of the literature

The best mode of undescended testis (UDT) treatment remains controversial. However, knowledge gained from randomized controlled studies and meta-analyses allowed different groups of researchers to set out guidelines on management of patients with UDT. The authors reviewed recent literature and came to the following conclusions: (1) Hormonal treatment is not recommended, considering both the immediate results (only 15-20% of retained testes descend) and the possible long-term adverse effects on spermatogenesis. (2) Surgery is the treatment of choice; orchiopexy is successful in about 95% of UDT, with a low rate of complications (about 1%). (3) Orchiopexy should be performed between 12 and 18 months of age, or at first contact if diagnosed later.

Colour Doppler and ultrasound characteristics of testicular Leydig cell tumours

OBJECTIVE

To assess the colour Doppler and ultrasound features of testicular Leydig cell tumours (LCTs) in a population of 38 surgically proven lesions.

METHODS

From August 2008 to March 2015, we retrospectively included 38 surgically proven LCTs in 36 patients. Clinical data, scrotal colour Doppler, B-mode ultrasound and videos images were reviewed for each patient. The volume, echotexture of the testis, size, shape, echogenicity and the vascularization pattern of the lesion were evaluated. The tumour margins were categorized as either smooth or lobulated. The vascularization was classified as intense, moderate or without any hypervascularization. We defined the vascularization pattern groups as central, peripheral and mixed (the latter meaning both central and peripheral).

RESULTS

26 patients were referred for infertility [5 patients were subsequently diagnosed with Klinefelter syndrome (KS) and 5 patients with cryptorchidism]. 28 patients underwent testis-sparing surgery, while 8 patients underwent a radical orchiectomy. The LCTs were mostly infracentimetric (68.4%), with a median size of 7.0 mm (ranging from 4.0 to 11 mm). 50% of the lesions had lobulated margins, and these were significantly larger than the smooth lesions (p < 0.05). The content of the lesions was markedly homogeneous and hypoechoic. All lesions had sharp demarcations from the adjacent pulp. 36/38 lesions exhibited moderate-to-intense hypervascularization, with a mixed intrinsic and peripheral rim pattern. Larger lesions were more hypervascularized (p < 0.05). LCTs in patients with KS had atypical features.

CONCLUSION

Typical sporadic LCTs appeared as isolated hypoechoic, infracentimetric masses, with a clear demarcation from the adjacent pulp. They presented intrinsic and peripheral rim hypervascularization.

ADVANCES IN KNOWLEDGE

By undertaking the largest imaging series of LCT to date (to our knowledge), we reassessed the typical sonographical aspects of LCTs, so as to provide guidance in regard to opting for testis-sparing surgery and for follow-up. LCTs present both intrinsic and rim vascularization detectable by colour Doppler ultrasound. Intrinsic vascularization and lobulated margins are common findings in testicular LCTs.

Does early orchidopexy improve fertility?

Cryptorchidism or undescended testis (UDT) is a common problem in the pediatric male population. While spontaneous testicular descent occurs in the majority of cases, orchidopexy is the definitive treatment in those with remaining cryptorchid testis. A long established sequela to cryptorchidism is reduced fertility in the adult male and recent guidelines have advocated for earlier orchidopexy as studies have shown improvement in fertility rates when surgery is performed before one year of age. Further studies continue to validate these recommendations as recent research demonstrates crucial developmental steps even in very young boys. These steps are critical to complete testicular maturation and a loss of these milestones has increasingly been shown to decrease fertility later in life. This review examines the histological findings, hormonal data, and paternity rates from those who have undergone orchidopexy at varying ages and summarizes current recommendations aimed at preserving fertility as much as possible in this population.

Outcomes of Laparoscopic Treatment Modalities for Unilateral Non-palpable Testes

PURPOSE

To date, laparoscopy has gradually become the gold standard for treatment of non-palpable testicles (NPT) with different success and complication rates. In this study, we aimed to evaluate outcomes of laparoscopic approaches for NPT.

MATERIALS AND METHODS

We reviewed data of 82 consecutive patients who underwent laparoscopic treatment for unilateral NPT at two institutions by two high volume surgeons from 2004 January to 2014 December. Laparoscopic-assisted orchidopexy (LAO) and two-stage Fowler-Stephens technique (FST) was performed for 45 and 37 patients, respectively. Age (at surgery), follow-up time, laterality of testes, and postoperative complications were analyzed. Modified Clavien classification system (MCCS) was used for evaluating complications.

RESULTS

The median age (at surgery) and median follow-up time were 18 (range: 6-56) and 60 (range: 9-130) months, respectively. Overall success rate for two laparoscopy techniques was 87.8% during the maximal follow-up time. We observed wound infection in two, hematoma in one, testicular atrophy in five, testicular re-ascending in two patients at follow-up period. There was no statistical difference between two laparoscopic techniques for grade I (five vs. two patients, p = 0.14) and grade IIIb MCCS complications (five vs. two patients, p = 0.44).

CONCLUSION

Our results have shown that two laparoscopic approaches have low complication rates.

Cryptorchidism and Fertility

Cryptorchidism, the failure of one or both testes to descend into the scrotum prenatally, occurs in 2.4%–5% of newborns. Many of these testes will descend spontaneously shortly after birth, but ~23% will remain undescended unless surgery is performed. Bilaterally cryptorchid men have a six times greater risk of being infertile when compared with unilaterally cryptorchid men and the general male population. Approximately 10% of infertile men have a history of cryptorchidism and orchidopexy. The main reasons for infertility in men with a history of cryptorchidism treated by orchidopexy are maldevelopment of the testes and an improper environment for the normal development of the testes, hyperthermia, and antisperm antibodies.

A rare Robertsonian translocation rob(14;22) carrier with azoospermia, meiotic defects, and testicular sperm aneuploidy

Male infertility is a serious problem in an increasing number of couples. We report an infertile man with non-obstructive azoospermia and karyotype 45,XY,rob(14;22). The immunofluorescence analysis of his testicular tissue using antibodies to SYCP1, SYCP3, HORMAD2, MLH1, and centromeres showed delayed synapsis of the chromosomes involved in the translocation, a varying extent of trivalent asynapsis and its association with sex chromosomes. The mean frequency of meiotic recombination per cell was within the range of normal values. Fluorescence in situ hybridization (FISH) with probes for chromosomes 14 and 22 revealed 5.83% of chromosomally abnormal testicular spermatozoa. FISH with probes for chromosomes X, Y, and 21 showed frequencies of disomic and diploid testicular spermatozoa increased when compared to ejaculated sperm of healthy donors, but comparable with published results for azoospermic patients. PGD by FISH for the translocation and aneuploidy of chromosomes X, Y, 13, 18, and 21 showed a normal chromosomal complement in one out of three analyzed embryos. A healthy carrier girl was born after the embryo transfer. This study shows the benefits of preimplantation genetic diagnosis in a case of a rare Robertsonian translocation carrier with azoospermia and a relatively low frequency of chromosomally unbalanced testicular spermatozoa.

Regulation of testicular descent

Testicular descent occurs in two morphologically distinct phases, each under different hormonal control from the testis itself. The first phase occurs between 8 and 15 weeks when insulin-like hormone 3 (Insl3) from the Leydig cells stimulates the gubernaculum to swell, thereby anchoring the testis near the future inguinal canal as the foetus grows. Testosterone causes regression of the cranial suspensory ligament to augment the transabdominal phase. The second, or inguinoscrotal phase, occurs between 25 and 35 weeks, when the gubernaculum bulges out of the external ring and migrates to the scrotum, all under control of testosterone. However, androgen acts mostly indirectly via the genitofemoral nerve (GFN), which produces calcitonin gene-related peptide (CGRP) to control the direction of migration. In animal models the androgen receptors are in the inguinoscrotal fat pad, which probably produces a neurotrophin to masculinise the GFN sensory fibres that regulate gubernacular migration. There is little direct evidence that this same process occurs in humans, but CGRP can regulate closure of the processus vaginalis in inguinal hernia, confirming that the GFN probably mediates human testicular descent by a similar mechanism as seen in rodent models. Despite increased understanding about normal testicular descent, the common causes of cryptorchidism remain elusive.

Hormonal therapy using gonadotropin releasing hormone for improvement of fertility index among children with cryptorchidism: a meta-analysis and systematic review

BACKGROUND/PURPOSE

Gonadotropin releasing hormone(GnRH) as an adjunct to orchidopexy for the treatment of cryptorchidism is still controversial. Present evidences were studied through a meta-analysis of comparative clinical trials.

METHOD

Systematic literature search was done up to September 30, 2013. Studies were independently appraised by two reviewers. Continuous data of fertility indices were extracted as weighted mean difference (WMD) and standard deviation (SD); while nominal data of fertility indices were extracted as relative risk (RR). Random effects model was used to analyze the pooled effect estimates. Inter-study heterogeneity and publication bias were assessed. PROSPERO Protocol registration (CRD42013004922).

RESULTS

Ten eligible studies were included. The pooled effect estimates showed that cryptorchid children treated with GnRH when compared with controls, have significantly increased germ cell per tubule (WMD: 0.35; 95% CI 0.07-0.62, P=0.01) and increased RR to have normal value of germ cell per tubule (RR: 2.86; 95% CI 1.73-4.71, P<0.0001). Inter-study heterogeneity was noted, source identified with subgroup analysis. Publication bias was not evident. No GnRH related adverse events were reported in all studies.

CONCLUSION

Evidence suggests that a subset of boys with cryptorchidism may benefit from GnRH as adjunctive to orchidopexy in improving the fertility index. However, future studies are recommended to specifically identify subgroup characteristics of cryptorchidism that will clearly benefit from the treatment.

Male infertility: assessment of juvenile testicular dysfunction and risk for malignancy in cryptorchid boys based on resin section evaluation

Infertility is sometimes more a man's problem than a woman's, failure of one or both of the testes to descend (cryptorchidism) being the most frequent genital malformation in boys. Untreated, the undescended testis impairs germ cell development and significantly reduces adult fertility. A-dark spermatogonia are the stem cells for all future spermatozoa, and their depletion can be reliably estimated in resin semithin sections. Additionally, there is an increased risk of testicular preneoplasia in the form of carcinoma in situ (CIS) cells. The authors report how the pathologic biopsy examination of juvenile cryptorchid testes can assess infertility and malignancy risk.

Gonocyte transformation to spermatogonial stem cells occurs earlier in patients with undervirilisation syndromes

AIM

Fertility post-orchidopexy is dependent on transformation of neonatal gonocytes (G) into adult dark spermatogonia at about 3 months, the same time as gonadotrophins stimulate androgen secretion. We examined how androgen blockade affects transformation of gonocytes to spermatogonial stem cells (SSC) during this period in patients with undervirilisation syndromes.

METHODS

Patients with undervirilisation syndromes (n=30, 1.5 weeks-16 years) underwent review of medical records, pathology reports, and H&E slides of testes (ethics HREC32164). Fluorescent immunohistochemistry against anti-Mullerian hormone (AMH, Sertoli cells), mouse VASA homologue (MVH, germ cells) and DAPI (nuclei) allowed the number of MVH-positive gonocytes/spermatogonial stem cells per seminiferous tubular cross-section (G/T or SSC/T) to be counted.

RESULTS

Gonocytes (MVH-positive cells in the tubular lumen) were present in 15/16 patients under 2 years old. SSC (MVH-positive cells on the tubule basement membrane) were present in 25/30 patients. With increasing age, the mean number of SSC/T decreased from ~4 to 0, and G/T decreased from ~1.5 to 0. SSC were present in CAIS and PAIS patients at 1.5 and 3.5 weeks old, respectively.

CONCLUSIONS

Gonocytes transform into SSC earlier than expected in patients with undervirilisation syndromes. Lack of androgens may stimulate non-androgenic regulators to trigger transformation. Understanding how gonocytes transform may enable optimization of spermatogonial development to preserve fertility post-orchidopexy.

Spermatogenesis and cryptorchidism

Cryptorchidism represents the most common endocrine disease in boys, with infertility more frequently observed in bilateral forms. It is also known that undescended testes, if untreated, lead to an increased risk of testicular tumors, usually seminomas, arising from mutant germ cells. In normal testes, germ cell development is an active process starting in the first months of life when the neonatal gonocytes transform into adult dark (AD) spermatogonia. These cells are now thought to be the stem cells useful to support spermatogenesis. Several researches suggest that AD spermatogonia form between 3 and 9 months of age. Not all the neonatal gonocytes transform into AD spermatogonia; indeed, the residual gonocytes undergo involution by apoptosis. In the undescended testes, these transformations are inhibited leading to a deficient pool of stem cells for post pubertal spermatogenesis. Early surgical intervention in infancy may allow the normal development of stem cells for spermatogenesis. Moreover, it is very interesting to note that intra-tubular carcinoma in situ in the second and third decades have enzymatic markers similar to neonatal gonocytes suggesting that these cells fail transformation into AD spermatogonia and likely generate testicular cancer (TC) in cryptorchid men. Orchidopexy between 6 and 12 months of age is recommended to maximize the future fertility potential and decrease the TC risk in adulthood.

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.

The controversy regarding the need for hormonal treatment in boys with unilateral cryptorchidism goes on: a review of the literature

Hormonal treatment for unilateral undescended testes continues to be recommended in some countries. We reviewed the literature in favor and against this recommendation. Since the paternity rate of men with a history of unilateral undescended testes only treated with surgery is normal, the effectiveness of hormonal treatment to produce testicular descent is low, the cost is considerable, and there are potential adverse effects, hormonal treatment for boys with unilateral undescended testes should no longer be recommended.

Is matrix metalloproteinase required in postnatal testicular tubules for germ cell maturation?

BACKGROUND/AIM

Cryptorchidism may cause infertility by failed transformation of neonatal gonocytes into adult dark spermatogonia, the putative stem cells for spermatogenesis. Gonocytes migrate centrifugally to the tubular basement membrane to become adult dark spermatogonia. Regulation of this transformation remains unknown. We aimed to investigate neonatal rodent testis matrix metalloproteinase (MMP) production to see whether MMPs loosen extracellular matrix between Sertoli cells to facilitate gonocyte movement.

METHODS

Sprague-Dawley rat testes (n = 4-6 per group) were collected at embryonic day 19 (E19) and postnatal (P) days P0 to 10 for immunohistochemistry. Immunofluorescent confocal images were captured for presence of membrane type 1 MMP (MT1-MMP), matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 2 (TIMP2), mouse VASA homologue, anti-Müllerian hormone, and androgen receptor in tissue sections. Testicular proteins were analyzed by immunoblotting.

RESULTS

Membrane type 1 MMP was strongly present in gonocytes at E19 then decreased, whereas it increased in testicular somatic cells from P0 to P10. Testicular protein levels of MT1-MMP, MMP2, and androgen receptor were constant from E19 to P10. Anti-Müllerian hormone protein sharply decreased after P2, whereas TIMP2 gradually increased from E19 to P10. Gonocytes migrated to basement membrane at P2 to P6.

CONCLUSION

Membrane type 1 MMP, MMP2, and TIMP2 were present in testis from E19 to P10 during gonocyte migration and transformation into spermatogenic stem cells. Increased knowledge about germ cell development may aid efforts to improve fertility in cryptorchidism.

Attenuation of spermatogonial stem cell activity in cryptorchid testes

PURPOSE

To elucidate the mechanism of infertility caused by cryptorchidism we focused on early stage spermatogenesis and spermatogonial stem cell activity in undifferentiated spermatogonia in cryptorchid testes.

MATERIALS AND METHODS

Histological findings and expression patterns of the stem cell marker undifferentiated embryonic cell transcription factor 1 were examined in a unilateral cryptorchid rat model. We removed unilateral descended testis and contralateral descended testis from cryptorchid and normal rats (control), respectively, 18 days postcoitum to 144 days postpartum.

RESULTS

In descended testes gonocyte differentiation into early A spermatogonia occurred at 9 days postpartum. However, this transformation was altered in undescended testes. Furthermore, the undifferentiated embryonic cell transcription factor 1 negative early A spermatogonia-to-positive early A spermatogonia ratio was significantly higher in the undescended testis group (mean ± SD 0.69 ± 0.04) than in the control (0.46 ± 0.10, p = 0.037) and descended testis (0.44 ± 0.05, p = 0.022) groups, indicating decreased early A spermatogonia with spermatogonial stem cell activity in cryptorchid testes.

CONCLUSIONS

In cryptorchid testes the differentiation from gonocytes into early A spermatogonia and the stem cell activity of early A spermatogonia were altered during the early stage of spermatogenesis, suggesting that the loss of spermatogonial stem cell activity in cryptorchid rats resulted in altered spermatogenesis, thus interfering with fertility.

Deficient expression of genes involved in the endogenous defense system against transposons in cryptorchid boys with impaired mini-puberty

Mini-puberty is the period between 30 and 80 days after birth when testosterone and gonadotropin surges occur in male infants to induce the transformation of gonocytes into adult/dark spermatogonia. Cryptorchid boys with impaired mini-puberty develop infertility despite timely and successful surgical treatment. The decreased germ cell count found in this group of boys could be the result of uncontrolled transposon activity inducing genomic instability and germ cell death. A genome-wide analysis of 18 cryptorchid and 4 control testes was performed with Affymetrix chips. We found that 5 of 8 genes that are important for transposon silencing were not expressed in the high azoospermia risk group of cryptorchid boys but were expressed in the low azoospermia risk and control groups. Two genes, CBX3 and DNMT1, were equally expressed in all 3 groups. Impaired expression of the DDX4, MAEL,MOV10L1, PIWIL2, PIWIL4, and TDRD9 genes in the group of cryptorchid boys at high risk of infertility indicates that gene instability induced by impaired expression of transposon silencing genes contribute to the development of azoospermia. Intact mini-puberty appears to be essential for the development of the endogenous defense system mediated by transposon silencing.

Acquired undescended testis: putting the pieces together

Acquired undescended testis is now a well-recognized disorder. It is seen in 1.5% of pre-pubertal boys and accounts for the 1-2% orchidopexy rate in older boys. Its pathogenesis remains largely unclear, but it may be caused by a fibrous remnant of the processus vaginalis. There is much controversy over its management, and the proper management awaits a randomized-controlled trial. Until now, follow-up data are available only for cases of spontaneous descent or pubertal orchidopexy. It is speculated that acquired undescended testis is in fact congenital and because of a short funiculus at birth, allowing a low-scrotal position early in life. However, as the boy grows, the testis might evolve into an undescended state. When testosterone surges at puberty, spontaneous descent occurs in three of every four cases.

[Cryptorchidism and infertility from the perspective of interdisciplinary guidelines]

Cryptorchidism is the most common genital disorder in boys. Early-born boys are affected in up to one third of the cases, while about 2-5% of full-term newborns suffer from at least one undescended testicle. As a result of short-term endogenous testosterone secretion after birth the prevalence decreases to 1-2% after 3 months. According to most studies, watchful waiting after 6 months is not justified because after this time spontaneous testicular descent only very rarely occurs. Even though the effects of testicular development and fertility in undescended testis have been extensively examined, the only fact that remains certain is that approximately 90% of untreated men with bilateral cryptorchidism develop azoospermia. The remaining scenarios of cryptorchidism (unilateral, ectopic, inguinal, treated or not treated) exhibit unpredictable fertility and likelihood of fatherhood.

Testicular gene expression in cryptorchid boys at risk of azoospermia

Despite timely and successful surgery, 32% of patients with bilateral and 10% with unilateral cryptorchidism will develop azoospermia. Cryptorchid boys at risk of azoospermia display a typical testicular histology of impaired mini-puberty at the time of the orchidopexy. During mini-puberty increased gonadotropin and testosterone secretion stimulate transformation of gonocytes into Ad spermatogonia. In the azoospermia risk group this transformation is to a great extent impaired. This study aimed to analyze data on whole genome expression signatures of undescended testes at risk of developing azoospermia. Twenty-three testicular biopsies from 22 boys were analyzed (19 testes from 18 boys with cryptorchidism and 4 contralateral descended testes from patients with testicular agenesis). Expression profiling identified 483 genes not or under-expressed in the azoospermia risk group compared with the control and low risk for azoospermia (LAZR) groups. Annotated loci were associated with spermatogenesis. Other significant genes were cellular defense response genes and hormone-controlled loci involved in spermatogenesis. Some genes transcribed in normal adult meiotic and post-meiotic germ cells are activated in healthy juvenile Ad spermatogonia. Thus, molecular events initiating the testicular expression program at the onset of puberty and maintaining it during adulthood occur very early in prepubertal testes. This molecular event is to a great extent impaired in the high risk for azoospermia (HAZR) group lacking Ad spermatogonia (stem cells for spermatozoa) indicating impaired mini-puberty.

Cryptorchidism and hypospadias as a sign of testicular dysgenesis syndrome (TDS): environmental connection

Cryptorchidism and hypospadias are common genital birth defects that affect 2-9% and 0.2-1% of male newborns, respectively. The incidence of both defects shows large geographic variation, and in several countries increasing trends have been reported. The conditions share many risk factors, and they are also interlinked to the risk of testis cancer and poor semen quality. Testicular Dysgenesis Syndrome (TDS) may underlie many cases of all these male reproductive health problems. Genetic defects in androgen production or action can cause both cryptorchidism and hypospadias, but these are not common. A monogenic reason for cryptorchidism or hypospadias has been identified only in a small proportion of all cases. Environmental effects appear to play a major role in TDS. Exposure to several persistent chemicals has been found to be associated with the risk of cryptorchidism, and exposure to anti-androgenic phthalates has been shown to be associated with hormonal changes predisposing to male reproductive problems. Despite progress in identification of endocrine-disrupting substances, we are still far from knowing all the risk factors for these birth defects, and advice for prevention must be based on precautionary principles.