Diagnostic and clinical features in azoospermia

Profiling of circulating extracellular vesicle microRNAs reveals diagnostic potential and pathways in non-obstructive and obstructive azoospermia†

The accurate diagnosis of non-obstructive azoospermia and obstructive azoospermia is crucial for selecting appropriate clinical treatments. This study aimed to investigate the pivotal role of microRNAs in circulating plasma extracellular vesicles in distinguishing between non-obstructive azoospermia and obstructive azoospermia, as well as uncovering the signaling pathways involved in azoospermia pathogenesis. In this study, differential expression of extracellular vesicle miR-513c-5p and miR-202-5p was observed between non-obstructive azoospermia and obstructive azoospermia patients, while the selenocompound metabolism pathway could be affected in azoospermia through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The predictive power of these microRNAs was evaluated using receiver characteristic operator-area under the curve analysis, demonstrating promising sensitivity, specificity, and area under the curve values. A binomial regression equation incorporating circulating plasma levels of extracellular vesicles miR-202-5p and miR-513c-5p along with follicle-stimulating hormone was calculated to provide a clinically applicable method for diagnosing non-obstructive azoospermia and obstructive azoospermia. This study presents a potentially non-invasive testing approach for distinguishing between non-obstructive azoospermia and obstructive azoospermia, offering a possibly valuable tool for clinical practice.

A novel ADGRG2 truncating variant associated with X-linked obstructive azoospermia in a large Chinese pedigree

PURPOSE

In this study, we aimed to identify sterility-related variants in a Chinese pedigree with male infertility and to reveal the different phenotypes and intracytoplasmic sperm injection (ICSI) outcomes of the affected members.

METHODS

Physical examinations were performed on male patients. G-band karyotype analysis, copy number variation sequencing, and quantitative fluorescent PCR were conducted to detect common chromosomal disorders in the probands. Whole-exome sequencing and Sanger sequencing were applied to identify the pathogenic genes and the protein expression changes caused by the very mutation were identified by Western Blot in vitro.

RESULTS

A novel nonsense mutation (c.908C > G: p.S303*) in the ADGRG2 was identified in all infertile male patients of the pedigree, which was inherited from their mothers. This variant was absent from the human genome databases. This mutation was also unexpectedly found in a male member with normal reproductive capability. Members with the mutation had different genitalia phenotypes, ranging from normal to dilated phenotypes of the vas deferens, spermatic veins and epididymis. There was a truncated ADGRG2 protein in vitro after mutation. Of the three patients' wives treated with ICSI, only one successfully gave birth.

CONCLUSIONS

Our study is the first to report the c.908C > G: p.S303* mutation in the ADGRG2 in an X-linked azoospermia pedigree and is the first to report normal fertility in a member with this mutation, expanding the mutation spectrum and phenotype spectrum of this gene. In our study, ISCI had a success rate of only one-third in couples including men with azoospermia with this mutation.

Circulatory exosomal tRF-Glu-CTC-005 and tRF-Gly-GCC-002 serve as predictive factors of successful microdissection testicular sperm extraction in patients with nonobstructive azoospermia

OBJECTIVE

To identify circulating plasma exosomal transfer RNA-derived fragments (tRFs) as the predictive factors of successful microdissection testicular sperm extraction (micro-TESE) in patients with nonobstructive azoospermia (NOA).

DESIGN

Case and control prospective study.

SETTING

Academic research laboratory.

PATIENT(S)

Twelve patients with NOA with successful sperm retrieval by micro-TESE, 18 patients with NOA with failed sperm retrieval by micro-TESE, and 12 normozoospermic fertile controls.

INTERVENTION(S)

Blood samples were collected from participants.

MAIN OUTCOME MEASURE(S)

The abundance of tRFs normalized as counts per million of the total aligned reads with the next-generation sequencing system; candidate tRF levels were validated through quantitative reverse transcription polymerase chain reaction; predictive accuracy was evaluated by the receiver operating characteristic area under the curve analysis. The nomogram was built for ranking.

RESULT(S)

The plasma circulating exosomal tRF-Gly-GCC-002 and tRF-Glu-CTC-005 manifested the most confident differential expression between patients with NOA with successful sperm retrieval by micro-TESE and patients with NOA with failed sperm retrieval by micro-TESE. The target gene prediction of these 2 tRFs followed by the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis indicated the functional enrichment of neuroendocrine protein metabolism and striatum/subpallium development. The herpes simplex virus 1 infection pathway was also involved. The receiver operating characteristic area under the curve (AUC) analysis demonstrated a promising predictive accuracy: tRF-Gly-GCC-002, AUC of 0.921, and tRF-Glu-CTC-005, AUC of 0.954. A regression model was built and presented with the nomogram for further assessment.

CONCLUSION(S)

This study described the exosomal tRF-Gly-GCC-002 and tRF-Glu-CTC-005 expression values, indicated a promising predictive effect for accessibility of sperm retrieval through micro-TESE from patients with NOA, and highlighted tRF-Gly-GCC-002 and tRF-Glu-CTC-005 as useful biomarkers in patients with NOA seeking in vitro conception with their residual sperm.

Azoospermia and reciprocal translocations: should whole-exome sequencing be recommended?

BACKGROUND

Although chromosome rearrangements are responsible for spermatogenesis failure, their impact depends greatly on the chromosomes involved. At present, karyotyping and Y chromosome microdeletion screening are the first-line genetic tests for patients with non-obstructive azoospermia. Although it is generally acknowledged that X or Y chromosome rearrangements lead to meiotic arrest and thus rule out any chance of sperm retrieval after a testicular biopsy, we currently lack markers for the likelihood of testicular sperm extraction (TESE) in patients with other chromosome rearrangements.

RESULTS

We investigated the use of a single nucleotide polymorphism comparative genome hybridization array (SNP-CGH) and whole-exome sequencing (WES) for two patients with non-obstructive azoospermia and testicular meiotic arrest, a reciprocal translocation: t(X;21) and t(20;22), and an unsuccessful TESE. No additional gene defects were identified for the t(X;21) carrier - suggesting that t(X;21) alone damages spermatogenesis. In contrast, the highly consanguineous t(20;22) carrier had two deleterious homozygous variants in the TMPRSS9 gene; these might have contributed to testicular meiotic arrest. Genetic defect was confirmed with Sanger sequencing and immunohistochemical assessments on testicular tissue sections.

CONCLUSIONS

Firstly, TMPRSS9 gene defects might impact spermatogenesis. Secondly, as a function of the chromosome breakpoints for azoospermic patients with chromosome rearrangements, provision of the best possible genetic counselling means that genetic testing should not be limited to karyotyping. Given the risks associated with TESE, it is essential to perform WES - especially for consanguineous patients.

Meiotic arrest occurs most frequently at metaphase and is often incomplete in azoospermic men

OBJECTIVE

To establish which meiotic checkpoints are activated in males with severe spermatogenic impairment to improve phenotypic characterization of meiotic defects.

DESIGN

Retrospective observational study.

SETTING

University medical center research laboratory and andrology clinic.

PATIENT(S)

Forty-eight patients with confirmed spermatogenic impairment (Johnsen scores 3-6) and 15 controls (Johnsen score 10).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Quantitative assessment of immunofluorescent analyses of specific markers to determine meiotic entry, chromosome pairing, progression of DNA double-strand break repair, crossover formation, formation of meiotic metaphases, metaphase arrest, and spermatid formation, resulting in a novel classification of human meiotic arrest types.

RESULT(S)

Complete metaphase arrest was observed most frequently (27%), and the patients with the highest frequency of apoptotic metaphases also displayed a reduction in crossover number. Incomplete metaphase arrest was observed in 17% of the patients. Only four patients (8%) displayed a failure to complete meiotic chromosome pairing leading to pachytene arrest. Two new types of meiotic arrest were defined: premetaphase and postmetaphase arrest (15% and 13%, respectively).

CONCLUSION(S)

Meiotic arrest in men occurs most frequently at meiotic metaphase. This arrest can be incomplete, resulting in low numbers of spermatids, and often occurs in association with reduced crossover frequency. The phenotyping approach described here provides mechanistic insights to help identify candidate infertility genes and to assess genotype-phenotype correlations in individual cases.

Genetic defects in human azoospermia

As with many other diseases, genetic testing in human azoospermia was initially restricted to karyotype analyses (leading to diagnostic chromosome rearrangement tests for Klinefelter and other syndromes). With the advent of molecular biology in the 1980s, genetic screening was broadened to analyses of Y chromosome microdeletions and the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR). Decades later, the emergence of whole-genome techniques has led to the identification of other genetic defects associated with human azoospermia. Although TEX11 and ADGRG2 defects are frequently described in men with azoospermia, most of the causal gene defects found to date are private (i.e. identified in a small number of consanguineous families).

Here, we provide an up-to-date overview of all the types of genetic defects known to be linked to human azoospermia and try to give clinical practice guidelines according to azoospermia phenotype. Along with homozygous mutations, polymorphisms and epigenetic defects are also briefly discussed. However, as these variations predispose to azoospermia, a specific review will be needed to compile data on all the particular genetic variations reported in the literature.

Mutational screening of NR5A1 gene encoding steroidogenic factor 1 in cryptorchidism and male factor infertility and functional analysis of seven undescribed mutations

OBJECTIVE

To study the role of NR5A1 in cryptorchidism and male factor infertility. Mutations in NR5A1 have been initially associated with primary adrenal insufficiency and 46,XY gonadal dysgenesis and more recently with less severe phenotypes, including preliminary descriptions in severe forms of male factor infertility. Far less clear is the possible involvement of NR5A1 mutations in cryptorchidism.

DESIGN

Retrospective cross-sectional cohort study and functional analysis of mutant proteins.

SETTING

University department.

PATIENT(S)

Nine hundred fifty-nine subjects, including children with cryptorchidism and adults with different semen phenotypes associated or not associated with a history of cryptorchidism.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Mutation screening of NR5A1 by sequencing all exons. Functional analysis of mutant proteins by transactivation assays of CYP11A1 and CYP17A1 promoters.

RESULT(S)

We identified seven undescribed and one previously described missense mutation in subjects with severe spermatogenic impairment, without (4/236, 1.7%) and with (3/85, 3.5%) a history of cryptorchidism. Newborns with cryptorchidism carry NR5A1 mutations at low frequency (0.7%), whereas no mutations were found in milder forms of infertility and normozoospermia, irrespective of the presence of cryptorchidism. The mutant proteins showed impaired transactivation of gonadal promoters. A single nucleotide polymorphism (rs1110061; c.437 G→C; p.Gly146Ala) was also associated with more severe forms of spermatogenic impairment with cryptorchidism.

CONCLUSION(S)

This study, combined with what is already known about NR5A1-associated phenotypes, suggests considering mutations in this gene as a novel genetic cause of more severe forms of male factor infertility, especially when associated with a history of cryptorchidism.

Variation of spermatogenic and Sertoli cell number detected by fine needle aspiration cytology (FNAC) in Iberian red deer during and out of the breeding season

The aim of the present study was to evaluate spermatogenesis in Iberian red deer, a short-day seasonal breeder, using the fine needle aspiration cytology (FNAC) technique. Reports on spermatogenesis in deer are limited and here, for the first time, FNAC has been used to evaluate changes in such physiological process during and out of the breeding season. Testes were collected from 51 stags from November 2010 to February 2011. The Sertoli index and spermatic index were significantly higher during the breeding season than out of the breeding season (P = 0.0477 and P = 0.0125, respectively). A similar pattern was described by histological analysis, in which both Sertoli cell number per tubular cross-section and Johnsen score decreased significantly from the breeding season to the non-breeding season (P = 0.0131 and P = 0.0010, respectively). Data provided by FNAC were correlated with histology: the Sertoli index was positively correlated with Sertoli cell number per tubular cross-section (P = 0.0015), whereas the spermatic index was correlated with the Johnsen score (P = 0.0497). The results of the present study indicate that FNAC is a reliable technique to evaluate spermatogenesis in Iberian red deer and suggest that Sertoli cell number is not stable in these species, reaching highest values during the breeding season.

Genetic evaluation of severe male factor infertility in Turkey: a cross-sectional study

OBJECTIVE

To determine the frequency, types of chromosomal abnormalities and Y chromosome microdeletions in patients with severe male factor infertility, and the association between clinical background and genetic abnormality.

STUDY DESIGN

A total of 322 infertile men; 136 men with severe oligozoospermia (sperm count <5 million/ml) and 196 with nonobstructive azoospermia were studied between April 2004 and November 2006 at the Dr. Zekai Tahir Burak Women's Health Education and Research Hospital, Ankara, Turkey. Blood, semen samples, and testicular biopsies of patients were obtained. Hormonal analysis (follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels), semen analysis, karyotype analysis, and PCR screening for Y chromosome microdeletions were performed.

RESULT(S)

Forty-eight out of 332 (14%) infertile men had a genetic abnormality. Twenty-four (7.2%) cases with karyotype abnormality were detected. The frequencies of karyotype abnormalities were Klinefelter's syndrome 17/24 (71%), translocation 3/24 (12%), mix gonadal dysgenesis 2/24 (8%), XX male 1/24 (4%), and 46XYY 1/24 (4%). Twenty cases (6%) infertile men had only Y chromosome microdeletions. The frequencies of the deleted areas were azoospermia factor (AZF)c 42%, AZFb 25%, AZFa 21%, AZFb, c 8%, and AZFa, c 4%. Four of the cases with Y chromosome microdeletions also had a concurrent karyotype abnormality.

CONCLUSION(S)

All patients with nonobstructive azoospermia and severe oligozoospermia (sperm count <5 million/ml) should undergo genetic screening.

Bone mineral density and testicular failure: evidence for a role of vitamin D 25-hydroxylase in human testis

WORKING HYPOTHESIS

Mutations in the CYP2R1 gene, highly expressed in the testis and encoding vitamin D 25-hydroxylase, result in a vitamin D deficiency and a defective calcium homeostasis leading to rickets.

OBJECTIVE

Our aim was to investigate CYP2R1 expression in pathological testis samples and relate this to vitamin D metabolism in testiculopathic patients. DESIGN, PATIENTS, SETTING: Testis samples for in vitro study and 98 young men were transversally evaluated at Padova's Center for Male Gamete Cryopreservation.

METHODS

CYP2R1 mRNA expression and protein production were evaluated by quantitative RT-PCR, Western blot analysis, and immunofluorescence. Hormonal and bone-marker levels, and bone densitometry by dual-energy x-ray absorptiometry, were determined in patients with Sertoli-cell-only syndrome and severe hypospermatogenesis.

RESULTS

We found a lower gene and protein expression of CYP2R1 in samples with hypospermatogenesis and Sertoli-cell-only syndrome (P < 0.05) and a colocalization with INSL-3, a Leydig cell marker, at immunofluorescence. In all testiculopathic patients 25-hydroxyvitamin D levels were significantly lower and PTH levels higher compared to controls (P < 0.05). Furthermore, testiculopathic patients showed osteopenia and osteoporosis despite normal testosterone levels compared with controls both with increased bone-marker levels and altered dual-energy x-ray absorptiometry in the femoral neck and lumbar spine (for all parameters, P < 0.05).

CONCLUSIONS

Our data show an association between testiculopathy and alteration of the bone status, despite unvaried androgen and estrogen levels and no other evident cause of vitamin D reduction. Further studies in larger cohorts are needed to confirm our results.

Assisted reproductive treatment applications in men with normal phenotype but 45,X/46,XY mosaic karyotype: clinical and genetic perspectives

OBJECTIVE

The 45,X/46,XY mosaic karyotype is expressed by a spectrum of genital phenotypes, ranging from normal males through to ambiguous genitalia and to normal females.

CASE REPORTS

We present three cases of men with azoospermia or severe oligozoospermia, and a 45,X/46,XY mosaic karyotype and two with a Y-chromosome microdeletion. Phenotypically, they appeared as normal males, with normal penis, scrotum and secondary sex characteristics. Testicular sperm extraction and aspiration were applied to patients, and couples were prepared for assisted reproductive therapy. All men with azoospermia or severe oligozoospermia were evaluated for karyotype and Y-chromosome microdeletion even if they had normal phenotypes.

CONCLUSION

Possibilities for finding sperm and the biologic paternity in subjects with 45,X/46,XY karyotype should be considered. Furthermore, the increased risk for testicular neoplasia with mosaic karyotypes should be taken into consideration.

The choice of assisted ejaculation method is relevant for the diagnosis of azoospermia in men with spinal cord injuries

STUDY DESIGN

Retrospective analysis of research data collected over >18 years at our center.

OBJECTIVES

Examine results of repeated semen retrievals in men with spinal cord injury (SCI) who were initially found to be azoospermic.

SETTING

Major university medical center.

METHODS

Three different groups were analyzed in this study. Group 1 (n = 15) consisted of patients who were found to be azoospermic after the first ejaculation obtained by penile vibratory stimulation (PVS) and who had subsequent ejaculates obtained by PVS. Group 2 (n = 8) consisted of patients who were found to be azoospermic after the first ejaculation obtained by PVS and who had subsequent ejaculates obtained by electroejaculation (EEJ). Group 3 (n = 18) consisted of patients who were found to be azoospermic after the first ejaculation obtained by EEJ and who had subsequent ejaculates obtained by EEJ.

RESULTS

In group 1 (PVS-PVS), the second ejaculate contained sperm in none of the 15 patients. In group 2 (PVS-EEJ), the second ejaculate contained sperm in three of eight patients. In group 3 (EEJ-EEJ), the second EEJ resulted in semen with sperm in 6 of 18 patients. In the 388 study subjects, the overall prevalence of azoospermia was 7.0%.

CONCLUSION

In a study of a large group of subjects with SCI, the vast majority had normal sperm concentrations. In the minority who were azoospermic on their first ejaculate, and who were past the acute phase of injury, obtaining a second ejaculate by EEJ versus PVS may be a reasonable step before proceeding to surgical sperm retrieval.

Testis transcriptome analysis in male infertility: new insight on the pathogenesis of oligo-azoospermia in cases with and without AZFc microdeletion

BACKGROUND

About 10% of cases of male infertility are due to the presence of microdeletions within the long arm of the Y chromosome (Yq). Despite the large literature covering this critical issue, very little is known about the pathogenic mechanism leading to spermatogenesis disruption in patients carrying these microdeletions. In order to identify the presence of specific molecular pathways leading to spermatogenic damage, testicular gene expression profiling was carried out by employing a microarray assay in 16 patients carrying an AZFc microdeletion or affected by idiopathic infertility. Hierarchical clustering was performed pooling the data set from 26 experiments (16 patients, 10 replicates).

RESULTS

An intriguing and unexpected finding is that all the samples showing the AZFc deletion cluster together irrespectively of their testicular phenotypes. This cluster, including also four patients affected by idiopathic infertility, showed a downregulation of several genes related to spermatogenesis that are mainly involved in testicular mRNA storage. Interestingly, the four idiopathic patients present in the cluster showed no testicular expression of DAZ despite the absence of AZFc deletion in the peripheral blood.

CONCLUSIONS

Our expression profiles analysis indicates that several forms of infertility can be triggered by a common pathogenic mechanism that is likely related to alterations in testicular mRNA storage. Our data suggest that a lack of testicular DAZ gene expression may be the trigger of such mechanism. Furthermore, the presence of AZFc deletions in mosaic or the loss of function of AZFc genes in absence of Yq deletion can perhaps explain these findings. Finally, based on our data, it is intriguing to hypothesize that DAZ gene dysfunctions can account for a larger number of previously thought "idiopathic" infertility cases and investigation of such testicular gene dysfunction can be important to reveal the molecular determinant of infertility than are undetected when only testing Yq deletions in peripheral blood.

POWER DOPPLER ULTRASOUND MAPPING IN NONOBSTRUCTIVE AZOOSPERMIC PATIENTS PRIOR TO TESTICULAR SPERM EXTRACTION

This study was conducted to localize the testicular regions, which have better blood circulation by power Doppler ultrasonography in patients with nonobstructive azoospermia before testicular sperm extraction (TESE), and to investigate whether these vascularized areas have a high sperm retrieval rate or not. We evaluated 110 testes of 55 cases that were diagnosed as nonobstructive azoospermia. The mean age of the study group was 33 years (range 26 to 42). Patients with Y chromosome microdeletions, karyotype and hormonal abnormalities (except elevated FSH levels) were excluded from the study. In all cases, testes were evaluated by power Doppler ultrasonography before testicular sperm extraction. Testis was divided vertically into five equal parts and the area with maximum vascularity was determined subjectively. During testicular sperm extraction, starting from best-perfused areas, biopsies were done. If no motile or sufficient amount of sperm was found, TESE procedure was tried on the contralateral testis. TESE were performed from 82 testes and for the regions that show good and poor vascularity. The sperm finding rate was 38% and 14%, respectively (OR = 3.55)(p = 0.001). Power Doppler ultrasound mapping of the testis in nonobstructive azoospermic cases is a reliable and informative method to assess spermatogenic foci. It is a noninvasive technique that minimizes the unnecessary removal of hormone producing tissue and gives chance to end the TESE earlier than currently practiced procedures.

Follicle-stimulating hormone treatment in oligozoospermic patients

Follicle-stimulating hormone (FSH) plays a crucial role in human reproduction. Already, in the fetal and neonatal developmental stages, FSH activates the proliferation of the Sertoli cells and successively, in the pubertal phase, induces the mitotic activity of the spermatogonia and supports cellular differentiation to the round spermatid stage. This physiological role in spermatogenesis has induced various attempts to treat idiopathic oligozoospermic men with FSH. It is well known that treatment with gonadotrophins is very effective in subjects affected by hypogonadotropic hypogonadism, often leading to the restoration of normal spermatogenesis. The success of this treatment in these men has brought the utilization of the therapy with FSH in infertile oligozoospermic subjects, aimed at obtaining a quantitative increase in sperm count. However, the results obtained so far are still controversial. In this article, the literature is reviewed and the authors' experience on using FSH treatment in oligozoospermic subjects is discussed.

Hormonal treatment of male infertility: FSH

FSH plays a crucial role in spermatogenesis. In the fetal and neonatal development stages, FSH activates the proliferation of the Sertoli cells and successively, during the pubertal phase, it influences the mitotic activity of the spermatogonia and encourages cellular differentiation, until arrival at the round spermatid stage. Because of its physiological role in spermatogenesis, various attempts have been made to treat idiopathic oligozoospermic men with FSH. However, the results obtained so far are still controversial. In this research, attention was focused on the possible criteria able to predict a seminal response to this specific hormonal treatment. Furthermore, the effectiveness of FSH therapy was evaluated in terms of sperm count and pregnancy rate. Thus far, based on more recent knowledge about the FSH receptor gene, the authors have correlated different polymorphisms of this gene with the outcome of FSH treatment. In this paper, the literature is reviewed and the authors' experience on using FSH in male infertility is discussed.

Molecular and clinical characterization of Y chromosome microdeletions in infertile men: a 10-year experience in Italy

CONTEXT

An explosive growth in Y chromosome long arm (Yq) microdeletion testing demand for male infertility occurred in the past few years. However, despite the progresses in the biology of this chromosome, a number of molecular and clinical concerns are not supported by definitive data.

OBJECTIVE

The objective was to provide information on the type and prevalence of microdeletions in infertile males, indication for testing, genotype-phenotype correlation, sperm aneuploidies, and genetic counseling.

DESIGN AND SETTING

We performed a prospective study from January 1996 to December 2005 in an academic clinic.

PATIENTS

We studied 3073 consecutive infertile men, of which 625 were affected by nonobstructive azoospermia and 1372 were affected by severe oligozoospermia. Ninety-nine patients with microdeletions are described here.

MAIN OUTCOME MEASURES

Yq microdeletions, seminal analysis, reproductive hormones, testicular cytology/histology, and sperm sex chromosomes aneuploidies were used as outcome measures.

RESULTS

The prevalence of microdeletions was 3.2% in unselected infertile men, 8.3% in men with nonobstructive azoospermia, and 5.5% in men with severe oligozoospermia. Only 2 of 99 deletions were found in men with more than 2 million sperm/ml. No clinical data are useful to identify a priori patients with higher risk of Yq microdeletions. Most deletions are of the AZFc-b2/b4 subtype and are associated with variable spermatogenic phenotype, with sperm present in 72% of the cases. Complete AZFa and AZFb (P5/Proximal P1) deletions are associated with Sertoli cell-only syndrome and alterations in spermatocyte maturation, respectively, whereas partial deletions in these regions are associated with milder phenotype and frequent presence of sperm. Men with AZFc-b2/b4 deletions produce a higher percentage of sperm with nullisomy for the sex chromosomes and XY-disomy.

CONCLUSIONS

This extensive clinical research expands the knowledge on genotype-phenotype relationships and confirms that the identification of Yq microdeletions has significant diagnostic and prognostic value, adding useful information for genetic counseling in these patients.

Treatment of male idiopathic infertility with recombinant human follicle-stimulating hormone: a prospective, controlled, randomized clinical study

OBJECTIVE

To evaluate the effects of treatment with FSH on seminal parameters and spontaneous pregnancy in male infertility.

DESIGN

Prospective, controlled, randomized clinical study.

SETTING

Infertility center at a university hospital.

PATIENT(S)

One hundred twelve men affected by idiopathic oligozoospermia.

INTERVENTION(S)

Patients were randomized into two groups: 62 subjects were treated with 100 IU of recombinant human FSH on alternate days for 3 months, and 50 patients did not receive any treatment. Semen analysis was performed in all subjects at the end of this period of treatment and after the following 3 months. Subjects who had not reached spontaneous pregnancy underwent assisted reproductive techniques.

MAIN OUTCOME MEASURE(S)

Seminal parameters, testicular cytologic analysis, FSH, LH, T, and inhibin B concentrations.

RESULT(S)

The treatment group considered as a whole did not show modifications in sperm parameters. However, a subgroup of these (30, 48.4%) had a significant increase of sperm count (responder group). In the period including 3 months after the withdrawal of FSH therapy, we observed a significantly higher spontaneous pregnancy rate in the responder group (5 of 30 [16.7%]) with respect to nonresponder and nontreated groups (1 of 32 [3.1%] and 2 of 50 [4.0%], respectively). Furthermore, the improvement of seminal parameters in the responder group allowed these patients to undergo less frequent IVF-ET/intracytoplasmic sperm injection.

CONCLUSION(S)

Results from this controlled, randomized clinical trial show that FSH therapy does not improve sperm concentration or pregnancy rate when infertile male patients are chosen solely by the clinical criteria of idiopathic oligospermia and normal FSH concentration. Subgroup analysis, however, does indicate that patients without maturation arrest in addition to the clinical scenario do benefit from medical therapy.

Testicular fine needle aspiration as a diagnostic tool in non-obstructive azoospermia

AIM

To report the fine needle aspiration cytology (FNAC) of the testes used as a diagnostic tool in non-obstructive azoospermic patients.

METHODS

One hundred and twenty-five non-obstructive azoospermic male candidates to intracytoplasmic sperm injetion (ICSI) were analysed for follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone and inhibin B plasma levels. They were classified into three groups on the basis of FNAC: 1) Sertoli cell-only syndrome (SCOS) (70); 2) severe hypospermatogenesis (42); and 3) maturation arrest (13). Then, all men underwent testicular sperm extraction (TESE) for sperm recovery for ICSI.

RESULTS

Mature spermatozoa were detected by FNAC in 24 of 42 men with severe hypospermatogenesis and nine of 13 men with maturation arrest; while they were retrieved by TESE in 29 of 70 men with SCOS, 35 of 42 men with severe hypospermatogenesis (including the 24 by FNAC) and 10 of 13 men with maturation arrest (including the nine by FNAC). The sensitivity and specificity of FNAC were 44.6 % and 100 %, respectively. There was no difference on testicular volume and hormonal parameters in men with and without sperm retrieved.

CONCLUSION

These findings suggest that FNAC may be a simple and valid diagnostic parameter in non-obstructive azoospermic men and it may represent a valid positive prognostic parameter for sperm recovery at TESE.

Genetic aspects of human male infertility: the frequency of chromosomal abnormalities and Y chromosome microdeletions in severe male factor infertility

OBJECTIVE

The main purpose of this study is to detect the frequency and type of both chromosomal abnormalities and Y chromosome microdeletions in patients with severe male factor infertility and fertile control subjects. The association between the genetic abnormality and clinical parameters was also evaluated.

METHODS

This study was carried out in 208 infertile and 20 fertile men. Results of 208 patients, 119 had non-obstructive azoospermia and 89 had severe oligoasthenoteratozoospermia (OAT). Seventeen out of 119 (14.3%) azoospermic patients and two out of 89 (2.2%) patients with OAT had Y chromosome microdeletions. In total, 19 cases with deletions were detected in 208 infertile men, with a frequency of 9.1%. The AZFc locus, mainly DAZ gene cluster was the most frequently deleted region. Five other cases with azoospermia (4.2%) and two cases with OAT (2.2%) had a chromosomal abnormality, with a total number of seven (3.4%). Including Y chromosome deletions and structural chromosome abnormalities, the rate of genetic abnormalities was 12.5% (26/208) in our patients. On the other hand, 20 men with proven fertility and fathers of five cases with microdeletions were genetically normal. Y chromosome deletions and chromosomal abnormalities were associated with various histological alterations in testis. Sertoli cell-only (SCO) syndrome and maturation arrest predominated in these cases, whereas hypospermatogenesis occurred more frequently in genetically normal patients.

CONCLUSION

Various chromosomal abnormalities and deletions of Y chromosome can cause spermatogenic breakdown resulting in chromosomally derived infertility. All these findings strongly support the recommendation of genetic screening of infertile patients.

Diagnostic and Prognostic Value of Testicular Fine Needle Aspiration in Non-Obstructive Azoospermia

Modern techniques of assisted reproduction may be useful also in non obstructive azoospermic men using sperm extracted from the testis (TESE). However, no clinical or hormonal parameter has reliable prognostic value in predicting the presence of testicular sperm. We report here our experience with fine needle aspiration cytology (FNAC) of the testes used as a diagnostic tool in non obstructive azoospermic patients looking at its possible role as prognostic parameter for the presence of testicular sperm at TESE.

Methods

One hundred and twenty-five non obstructive azoospermic men candidates to ICSI were analysed for FSH, LH, testosterone, and inhibin B plasma levels, and classified in three groups on the basis of FNAC: Sertoli cell-only syndrome (70), severe hypospermatogenesis (42), and maturation arrest (13). After that, all men underwent TESE for sperm recovery for ICSI.

Results

FNAC detected sperm in 24 of 42 men with severe hypospermatogenesis and 9 of 13 men with maturation arrest. TESE retrieved sperm in all such patients, as well as in additional 29 of 70 men with Sertoli cell-only syndrome, additional 11 cases of severe hypospermatogenesis (35 of 42 in total) and 1 additional case of maturation arrest (10 of 13 in total). Testicular volume and hormonal parameters were not different in men with and without sperm retrieved.

Conclusion

These findings suggest that FNAC may be a simple and valid diagnostic parameter in non obstructive azoospermic men, and it may represent a valid positive prognostic parameter for sperm recovery at TESE.

Percutaneous epididymal sperm aspiration: a diagnostic tool for the prediction of complete spermatogenesis

The classification of azoospermia into obstructive or non-obstructive is largely based on medical history, physical examination and biochemical markers in serum and semen. However, the most accurate parameter for diagnosis is the testicular histology. The predictive value of the percutaneous epididymal sperm aspiration (PESA), FSH, LH, testosterone, inhibin-B and testicular volume was investigated for their accuracy to predict a complete spermatogenesis (Johnsen score > or =8) in order to replace the testicular histology. The specificity and sensitivity of FSH, inhibin-B, LH, testosterone, testicular volume, and the presence of sperm in a PESA procedure was evaluated in 147 azoospermic males attending the centre for infertility diagnosis. A positive PESA outcome presented the highest sensitivity and specificity to predict a Johnsen score > or =8 (93 and 94% respectively) compared with FSH (90 and 19%), inhibin-B (88 and 57%) and testicular volume (95 and 45%). Differences in clinical presentation were observed between patients with positive sperm retrieval with PESA, depending on the aetiology of obstruction. In conclusion, the presence of spermatozoa in the epididymis (PESA+) correlates with a Johnsen score > or =8 and is the most accurate parameter to predict complete spermatogenesis compared with clinical or biochemical parameters. Between obstructive azoospermic patients, the clinical parameters observed varied according to the aetiology.

Male infertility

Infertility affects 13-18% of couples and growing evidence from clinical and epidemiological studies suggests an increasing incidence of male reproductive problems. The pathogenesis of male infertility can be reflected by defective spermatogenesis due to pituitary disorders, testicular cancer, germ cell aplasia, varicocele and environmental factors or to defective sperm transport due to congenital abnormalities or immunological and neurogenic factors. Recent studies suggest an increased incidence of genetic disorders related to male infertility which may affect different levels, interfering with germ cell generation and maturation or leading to the production of non-functional spermatozoa. The identification of genetic causes of male infertility raises the issue of the transmission of defects to the offspring, a situation that is becoming more important given the increasing use of intracytoplasmic sperm injection (ICSI), a procedure in which the natural selection of the spermatozoa is by-passed. Fertilization can occur in vitro using ejaculated, epididymal or testicular spermatozoa, either fresh or frozen-thawed, providing opportunities hitherto not possible for men to be genetic fathers.

The human Y chromosome's azoospermia factor b (AZFb) region: sequence, structure, and deletion analysis in infertile men

Microdeletions of the Y chromosome long arm are the most common mutations in infertile males, where they involve one or more "azoospermia factors" (AZFa, b, and c). Understanding of the AZF structure and gene content and mapping of the deletion breakpoints in infertile men are still incomplete. We have assembled a complete 4.3 Mb map of AZFb and surrounding regions by means of 38 BAC clones. The proximal part of AZFb consists of large repeated sequences organised in palindromes, but most of it is single copy sequence. A number of known and novel genes and gene families map in this interval, and most of them are testis specific or have testis specific transcripts. STS mapping allowed us to identify four severely infertile subjects with a deletion in AZFb with similar breakpoints, therefore suggesting a common deletion mechanism. This deletion includes at least five single copy genes and two duplicated genes, but does not remove the historical AZFb candidate gene RBMY1. These data suggest that other genes in AZFb may have important roles in spermatogenesis. We had no evidence for homologous recombination between large repeats as a possible deletion mechanism, as shown for AZFa and AZFc. However, identical sequences in AZFb and AZFc exist, and this finding could explain deletions found in these regions.

Stage-specific expression of genes associated with rat spermatogenesis: characterization by laser-capture microdissection and real-time polymerase chain reaction

Spermatogenesis in the rat consists of 14 unique morphologic cellular associations between Sertoli cells and developing germ cells within the seminiferous epithelium. The complexity of the cellular associations leads to difficulty in the isolation of individual cells at a defined stage of development for the study of their unique patterns of gene or protein expression. Thus, laser-capture microdissection is an ideal technique to permit such analysis. This study used laser-capture microdissection and real-time reverse transcription-polymerase chain reaction (RT-PCR) to quantitate the stage-specific expression of a series of genes of functional significance in hormonal regulation and cell-cell interactions in spermatogenesis, including cathepsin-L, CREM-tau, transition protein-1, androgen receptor, beta1-integrin, N-cadherin, and hypoxanthine phosphoribosyltransferase (HPRT). Frozen sections (10 micro m) were obtained from normal adult rat testes. Laser-capture microdissection (LCM) was used to capture all cells in cross-sections of seminiferous tubules that were grouped into stages I-V, VII-VIII, and IX-XIII. Transition protein-1 expression was lowest during stages I-V and increased 5.9-fold during stages VII-VIII and IX-XIII (P < 0.01). Cathepsin-L expression was highest during stages I-V and VII-VIII, falling 4.9-fold during stages IX-XIII (P < 0.05). Similarly, CREM-tau expression was highest during stages I-V and VII-VIII, falling 1.6-fold during stages IX-XIII (P < 0.05). A novel CREM-tau isoform lacking the phosphorylation domain was also characterized but was not stage-specific. beta1-Integrin, N-cadherin, and androgen receptor expression did not change between the spermatogenic stages examined. HPRT housekeeper expression was lowest during stages I-V but increased 1.5-fold during stages VII-VIII and IX-XIII (P < 0.05). This study is the first to apply LCM and real-time RT-PCR analysis to quantitate stage-specific changes in the expression of multiple genes in the seminiferous epithelium.

Use of recombinant human follicle-stimulating hormone in the treatment of male factor infertility

OBJECTIVE

To evaluate the effects of treatment with recombinant human FSH (r-hFSH) on seminal parameters and seminiferous epithelium in idiopathic patients with oligozoospermia with normal FSH plasma levels.

DESIGN

Randomized single-blind study.

SETTING

Academic setting.

PATIENT(S)

Forty-five subjects with idiopathic oligozoospermia (sperm count <10 x 10(6)/mL) and normal FSH and inhibin B plasma levels.

INTERVENTION(S)

Three months of treatment with r-hFSH 50 IU (15 patients) or with r-hFSH 100 IU on alternate days (15 patients) or no treatment (15 patients); bilateral testicular fine-needle aspiration (FNA) performed before and after therapy; FSH and inhibin B plasma levels evaluated during treatment.

MAIN OUTCOME MEASURE(S)

Seminal parameters; testicular cytological features evaluated by FNA; plasma levels of FSH, LH, T, and inhibin B.

RESULT(S)

Treatment with r-hFSH at a dose of 50 IU induced no increase in sperm concentration, while treatment with r-hFSH at a dose of 100 IU induced a significant increase in sperm concentration. In particular, in 11/15 patients a doubling of the pretreatment sperm concentration was observed. No significant increase in sperm parameters was observed in the control group. In both groups of patients treated with r-hFSH, the cytological analysis before treatment showed hypospermatogenesis. An increase in the percentage of spermatogonia and spermatocytes was observed only after the treatment with r-hFSH at a dose of 100 IU.

CONCLUSION(S)

The findings of this study demonstrate that r-hFSH at a dose of 100 IU, as previously seen with highly purified FSH, increases the spermatogonial population and sperm production in idiopathic patients with oligozoospermia with normal FSH and inhibin B plasma levels and a cytological picture of hypospermatogenesis.

A novel approach for the analysis of DAZ gene copy number in severely idiopathic infertile men

The deleted-in-azoospermia (DAZ) gene family constitutes the major candidate for the AZFc (azoospermia factor c) phenotype of male infertility, being deleted in about 10% of azoospermic and severely oligozoospermic subjects. Four DAZ genes are arranged in two clusters in AZFc, and standard analysis by PCR cannot distinguish among the different copies. Therefore only deletions of the entire gene cluster can be identified. We developed a PCR amplification-restriction digestion assay able to distinguish from DAZ genes for single nucleotide variants. Then we applied this approach to screen a group of idiopathic infertile men in which the DAZ genes presence was previously assessed by standard PCR analysis. Two patients out of 25 showed deletion of two copies of DAZ (DAZI and 2), suggesting that this mutation was actually the cause of spermatogenic damage. This preliminary screening demonstrates that deletions of copies of DAZ genes may be often found in severely infertile men and it strengthens the role of this gene family in spermatogenesis. Furthermore, this simple method, being able to distinguish among the different DAZ copies, could be used to screen a larger number of patients and to perform a more accurate diagnosis.

Y chromosome microdeletions and alterations of spermatogenesis

Three different spermatogenesis loci have been mapped on the Y chromosome and named "azoospermia factors" (AZFa, b, and c). Deletions in these regions remove one or more of the candidate genes (DAZ, RBMY, USP9Y, and DBY) and cause severe testiculopathy leading to male infertility. We have reviewed the literature and the most recent advances in Y chromosome mapping, focusing our attention on the correlation between Y chromosome microdeletions and alterations of spermatogenesis. More than 4,800 infertile patients were screened for Y microdeletions and published. Such deletions determine azoospermia more frequently than severe oligozoospermia and involve especially the AZFc region including the DAZ gene family. Overall, the prevalence of Y chromosome microdeletions is 4% in oligozoospermic patients, 14% in idiopathic severely oligozoospermic men, 11% in azoospermic men, and 18% in idiopathic azoospermic subjects. Patient selection criteria appear to substantially influence the prevalence of microdeletions. No clear correlation exists between the size and localization of the deletions and the testicular phenotype. However, it is clear that larger deletions are associated with the most severe testicular damage. Patients with Y chromosome deletions frequently have sperm either in the ejaculate or within the testis and are therefore suitable candidates for assisted reproduction techniques. This possibility raises a number of medical and ethical concerns, since the use of spermatozoa carrying Y chromosome deletions may produce pregnancies, but in such cases the genetic anomaly will invariably be passed on to male offspring.

Y-chromosome microdeletion and its effect on reproductive decisions in taiwanese patients presenting with nonobstructive azoospermia

OBJECTIVES

To investigate the position, extent, and frequency of Y chromosome microdeletions in Taiwanese patients presenting with nonobstructive azoospermia, and to investigate the effect of microdeletions on reproductive decisions.

METHODS

We studied 176 consecutive men with azoospermia in our urology clinic. Polymerase chain reaction tests were performed in 94 patients with nonobstructive azoospermia, and a series of 27 sequence-tagged sites (STSs) mapped within intervals 5 and 6 of Yq11 was selected for analysis. Clinical genetics counseling was provided to couples with microdeletions, and these couples made their own choices about further treatment modalities.

RESULTS

Among 94 patients screened for microdeletion, 11 (11.7%) showed microdeletions of one or more STSs. One had a deletion confined to the azoospermia factor b (AZFb) region (encompassing the RBM gene). Two were found to have deletions of both the AZFb and AZFc regions. Eight patients had deletions in the AZFc region (encompassing the DAZ gene). Five had deletions distal to the DAZ gene family. One had multiple, noncontiguous deletions. In 8 patients with testicular histology available, a lack of genotype/phenotype correlation was noted. Of the 11 couples with deletions, 3 thought microdeletion was a serious defect and opted for an artificial insemination of donor or adoption, 5 chose intracytoplasmic sperm injection, and the other 3 decided to undergo treatment with Chinese medicinal herbs.

CONCLUSIONS

The most commonly deleted region in the Taiwanese population is AZFc. The genes implicated in Taiwanese spermatogenesis defects are the DAZ and RBM gene families. Twenty-seven percent of couples with microdeletions deferred assisted reproductive technologies because of concern about their underlying genetic defects.

Male infertility caused by a de novo partial deletion of the DAZ cluster on the Y chromosome

Deletions in distal Yq interval 6 represent the cause of 10-15% of idiopathic severe male infertility and map to a region defined AZFc (azoospermia factor c). The testis-specific gene DAZ is considered a major AZFc candidate, and its deletion has been associated with a severe disruption in spermatogenesis. However, DAZ is actually a multicopy gene family consisting of seven clustered copies spanning about 1 megabase. Only deletions removing the entire DAZ gene cluster together with other genes have been reported in infertile males. Because no case of spermatogenic failure has been traced to intragenic deletions, point mutations, or even deletions not involving all the DAZ copies, the definitive proof for a requirement of DAZ for spermatogenesis is still debatable. Here we report the first case of a partial deletion of the DAZ cluster removing all but one of the copies. This deletion is present in a patient affected with severe oligozoospermia who had a testicular phenotype characterized by a great quantitative reduction of germ cells (severe hypospermatogenesis). The absence of this deletion in the fertile brother of the patient suggests that this de novo mutation indeed caused the spermatogenic failure.

FSH in the treatment of oligozoospermia

The aim of this study was to individuate parameters able to distinguish oligozoospermic subjects who will respond to follicle-stimulating hormone (FSH) therapy. A group of 135 oligozoospermic subjects was divided in three groups considering basal FSH and inhibin B concentrations: group A (normal FSH and inhibin B) characterized by moderate hypospermatogenesis sometimes associated to partial spermatidic arrest; group B (high FSH and normal inhibin B) characterized by hypospermatogenesis associated or not to spermatogonial/spermatocytic arrest; group C (high FSH and low inhibin B) characterized by severe hypospermatogenesis. Seventy-eight patients were treated with FSH at the dose of 75 IU on alternate days while 57 were treated with the same dose every day for 3 months. After FSH treatment a significant increase in ejaculated sperm concentration was observed only in oligozoospermic subjects with normal basal FSH and inhibin B plasma levels (group A) showing a testicular cytological picture of moderate hypospermatogenesis. In these subjects no differences in sperm production were observed between the two protocols of therapy. In the remaining patients of group A, characterized by hypospermatogenesis associated with maturation arrest at spermatidic level and in group B and C, no increase in sperm concentration was observed after therapy. These data suggest that FSH treatment may have a role in oligozoospermic subjects only when the spermatogenetic alterations consist in germ cell depopulation without maturative disturbances and with normal FSH concentrations.

Y chromosome microdeletions in infertile men with varicocele

The pathogenic mechanisms by which varicocele disrupt spermatogenesis are not clearly understood and it is possible that when varicocele is associated with a severe bilateral testiculopathy, other causes may represent the actual aetiological factor. Since microdeletions in the Y chromosome long arm (Yq) have become in last years a major cause of male infertility, we perform a Yq microdeletion screening in infertile men with varicocele. We selected 40 patients with severe oligozoospermia (sperm count<5x10(6)/ml, group 1) and 80 with varicocele and mild oligozoospermia (sperm count 10-20x10(6)/ml, group 2). Deletions of Yq was observed in seven out of 40 patients (17.5%) of group 1, while no deletions were found in patients of group 2, suggesting that the bilateral testicular damage observed in patients of group 1 is due to the underlying genetic anomaly, and not to varicocele itself. The finding of a genetic aetiology in infertile men with varicocele suggests that in such patients a Yq microdeletion screening should be performed, both for a proper diagnosis and to avoid unnecessary treatments that will probably not improve the sperm count.

Efficiency of the process of meiosis in scrotal testes of healthy boars and unilateral abdominal cryptorchid boars

Unilateral abdominal cryptorchidism has usually been correlated with abnormalities in the spermatogenic activity of the scrotal testis. The present study describes the effects of unilateral abdominal cryptorchidism on the meiotic process in scrotal testes from postpubertal boars. The percentage of primary spermatocytes, secondary spermatocytes, and round spermatids was evaluated in testicular smears from scrotal testes of healthy boars and of right-sided unilateral abdominal cryptorchid boars. As compared to the scrotal testes of healthy boars, the scrotal testes of unilateral abdominal cryptorchid boars showed low transformation from primary to secondary spermatocytes (meiosis I), but normal transformation from secondary spermatocytes to round spermatids (meiosis II). The data obtained indicate that spontaneous unilateral abdominal cryptorchidism on the right side induced partial arrest of spermatogenesis at the primary spermatocyte stage that was attributed to anomalies in Sertoli-cell activity. Abnormal paracrine signals from altered Sertoli cells could have resulted in either disturbed mitosis, which led to the formation of spermatocytes with an abnormal DNA content, or abnormalities in the metabolic activity and the organization of the cytoskeleton of primary spermatocytes.

Y chromosome microdeletions in cryptorchidism and idiopathic infertility

To clarify whether cryptorchidism might be the expression of an intrinsic congenital testicular abnormality, we investigated the frequency of Y chromosome long arm (Yq) microdeletions in unilateral excryptorchid subjects manifesting an important bilateral testiculopathy. Microdeletion analysis of Yq was performed by polymerase chain reaction in the following subjects: 40 unilateral excryptorchid patients with azoospermia or severe oligozoospermia due to a bilateral severe testiculopathy (Sertoli cell-only syndrome or severe hypospermatogenesis); 20 unilateral excryptorchid men with moderate oligozoospermia and a normal testicular cytological picture in the contralateral testis; 110 patients affected by idiopathic severe primary testiculopathies; 20 patients affected by idiopathic moderate testiculopathy; and, as controls, 50 patients affected by known causes of testiculopathy and 100 fertile men. Eleven of 40 (27.5%) unilateral excryptorchid patients affected by bilateral testiculopathy and 28 of 110 (25.4%) patients affected by idiopathic severe primary testiculopathy showed Yq microdeletions, whereas no microdeletions were found in all the other subjects, nor in male relatives of patients with deletions. Microdeletions were located in different parts of Yq, including known regions involved in spermatogenesis (DAZ and RBM, AZFa, b, and c) and other loci still poorly defined. No difference in localization of deletions was evident between cryptorchid and idiopathic patients. Microdeletions in Yq may be responsible for severe bilateral testicular damage that could be phenotypically expressed by unilateral cryptorchidism, as well as by idiopathic infertility.

Absence of testicular DAZ gene expression in idiopathic severe testiculopathies

Deletions of the DAZ (deleted in azoospermia) gene family are frequently responsible for male infertility and are generally assessed by analyses of genomic DNA extracted from peripheral leukocytes. The multicopy nature of this gene prevents the distinction of intragenic deletions or deletions not involving the whole DAZ gene cluster. Thus it is still unclear whether each DAZ copy is effectively expressed in the testis. We analysed, by reverse transcription-polymerase chain reaction (RT-PCR), the expression of DAZ, RBM and SRY genes, in testicular cells from infertile men affected by idiopathic severe hypospermatogenesis, obstructive azoospermia and Sertoli cell-only syndrome. Normal mRNA for DAZ, RBM and SRY were observed in obstructive azoospermia, whereas only SRY transcripts were detected when only Sertoli cells were present. Nine out of 10 patients affected by idiopathic severe hypospermatogenesis had normal expression of SRY, RBM and DAZ, while in one patient no DAZ transcript was detected, suggesting that his testiculopathy was related to the absence of DAZ expression. The lack of DAZ mRNA in testicular cells with an apparently normal DAZ gene constitution on DNA extracted from leukocytes may be explained by different hypotheses: (i) not all the copies of the DAZ gene cluster are transcribed in the germ cells and the reported patient had a small deletion involving only the active ones; (ii) the patient may be mosaic for the DAZ gene having a normal constitution in leukocytes and be deleted for DAZ gene in the testis; (iii) abnormalities of DAZ transcription may exist. These findings highlight the intrinsic interpretative difficulties of normal PCR analysis for DAZ and RBM on leukocytes and suggest caution in the use of germ cells for assisted reproductive techniques in these cases to avoid transmission of genetic abnormalities to male offspring.

Human male infertility and Y chromosome deletions: role of the AZF-candidate genes DAZ, RBM and DFFRY

Microdeletions in Yq11 overlapping three distinct 'azoospermia factors' (AZFa-c) represent the aetiological factor of 10-15% of idiopathic azoospermia and severe oligozoospermia, with higher prevalence in more severe testiculopathies, such as Sertoli cell-only syndrome. Using a PCR-based screening, we analysed Yq microdeletions in 180 infertile patients affected by idiopathic Sertoli cell-only syndrome and different degrees of hypospermatogenesis, compared with 50 patients with known causes of testicular alteration, 30 with obstructive azoospermia, and 100 normal fertile men. In idiopathic severe testiculopathies (Sertoli cell-only syndrome and severe hypospermatogenesis), a high prevalence of microdeletions (34.5% and 24.7% respectively) was found, while milder forms were not associated with Yq alteration. No deletions were found in testiculopathies of known aetiology, obstructive azoospermia, normal fertile men and male relatives of patients with deletions. Deletions in the AZFc region involving the DAZ gene were the most frequent finding and they were more often observed in severe hypospermatogenesis than in Sertoli cell-only syndrome, suggesting that deletions of this region are not sufficient to cause complete loss of the spermatogenic line. Deletions in AZFb involving the RBM gene were less frequently detected and there was no correlation with testicular phenotype, with an apparent minor role for such gene in spermatogenesis. The DFFRY gene was absent in a fraction of patients, making it a candidate AZFa gene. Our data suggest that larger deletions involving more than one AZF-candidate gene are associated with a more severe testicular phenotype.

Inhibin B levels in azoospermic subjects with cytologically characterized testicular pathology

BACKGROUND AND OBJECTIVE

Inhibin B, a heterodimeric glycoprotein of gonadal origin, is the most important circulating form of inhibin in human males and an inverse relationship between inhibin B and FSH plasma levels was been recently observed. Azoospermia represents the end-point of different kinds of testicular damage, ranging from a normal spermatogenic pattern (obstructive forms) to the complete absence of germ cells (Sertoli Cell Only Syndrome, SCOS). Furthermore, azoospermia may be related to maturational disturbances at different levels (spermatogonial, spermatocytic, spermatidic). To better define the relationship between testicular damage and inhibin levels and to evaluate the diagnostic value of this hormone in the management of subjects with azoospermia, we performed specific inhibin B assays in a group of azoospermic subjects affected by different kinds of testicular pathology.

PATIENTS

Eighty-nine azoospermic men were studied by testicular ultrasound examination, fine needle aspiration of the testes and hormonal parameters (FSH, LH and testosterone, inhibin B). Thirty normozoospermic subjects were considered as controls for seminal and hormonal parameters.

DESIGN AND RESULTS

On the basis of cytological analysis five different testicular appearences were identified in azoospermic patients: (i) Sertoli cell only syndrome (SCOS); (ii) Severe hypospermatogenesis; (iii) Spermatogonial and/or spermatocytic arrest; (iv) Spermatidic arrest; (v) Normal germ line (obstructive forms). No difference in LH and testosterone levels was found among the different groups. A significant negative correlation was present between inhibin B and FSH both in azoospermic men (r = - 0.503, P < 0.0001) and normozoospermic controls (r = -0.361, P < 0.05). Groups characterized by obstructive azoospermia and spermatidic arrest showed inhibin B concentrations similar to normozoospermic subjects (130.7 +/- 73.5, 160.3 +/- 35.1 and 148.5 +/- 46.8 ng/l, respectively), while groups characterized by SCOS, severe hypospermatogenesis and spermatogonial and/or spermatocytic arrest showed mean inhibin B concentrations significantly lower than controls (56.5 +/- 56.0, 57.9 +/- 31.2; 48.9 +/- 16.7 ng/l, respectively). In the group of SCOS, 8 out of 42 subjects (19.0%) showed inhibin B concentrations within the normal range despite high FSH levels.

CONCLUSIONS

This study demonstrated that, in humans, spermatids play an important role in the mechanism regulating inhibin B secretion by Sertoli cells. The significance of this hormone as a diagnostic parameter in azoospermic patients does not seem to be specific because it does not permit discrimination between obstructive forms or spermatidic arrest. Furthermore, despite an evident clinical, cytological and hormonal pattern for SCOS, inhibin B levels are normal in some of these patients. The significance of this latter result remains to be elucidated.

Relationship between hormone levels and testicular biopsies of azoospermic men

This study was conducted to evaluate the testicular biopsies and the sera levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), testosterone (T), and prolactin (PRL) in 96 azoospermic men attending the Andrology Clinic. Plasma levels of FSH were the most common hormone abnormality in the evaluation of azoospermia. Plasma levels of LH and T were useful only in azoospermic men with hypogonadism, whereas plasma PRL levels rarely occurred in azoospermia.

Morphologic study of the testes from spontaneous unilateral and bilateral abdominal cryptorchid boars

Macroscopical and histological characteristics were examined in both testes from three healthy boars, three boars with unilateral abdominal cryptorchidism on the right side, and three boars with bilateral abdominal cryptorchidism. Abdominal cryptorchidism, unilateral and bilateral, provoked a significant decrease of the weight and volume of the ectopic testes. The scrotal testis of the unilateral cryptorchid boars showed an increase in its volume and weight. Cryptorchidism also induced abnormalities in the histological structure of seminiferous tubules, lamina propria, and interstitial tissue of the abdominal testes. The number of seminiferous tubules decreased; the seminiferous epithelium was constituted by few spermatogonia with an atypical pattern and by abnormal Sertoli cells. The lamina propria showed a variable degree of thickening and collagenization. The interstitial tissue was very developed but displayed a decrease in the Leydig cell population. These abnormalities were more critical in bilateral cryptorchidism than in unilateral cryptorchidism. The scrotal testis of the unilateral cryptorchid boars showed normal appearance, but a decrease of the number of seminiferous tubules was observed. Moreover, the seminiferous tubules showed impaired spermatid maturation. The alterations observed in the abdominal testes of the unilateral and bilateral cryptorchid boars were attributed to defective proliferation and differentiation of Sertoli cells and Leydig cells. The anomalies in the scrotal testis of the unilateral cryptorchid boars were due to disturbances in the Sertoli cell activity.

Role of testicular fine needle aspiration in the diagnosis of azoospermia

Fine needle aspiration (FNA) of the testis is gaining recognition as an important step in the diagnosis of azoospermia. In 1000 azoospermic men receiving a short-acting anaesthetic, each testis was subject to FNA from three standard sites--lower, middle and upper zones--using 26-gauge needles. Azoospermia was graded in the following way: adequate spermatozoa (A1), low, scanty or rare spermatozoa (A2), spermatid arrest (B1), spermatocyte arrest (B2), Sertoli cell-only pattern (C) and sclerosis (D). The FNA grade showed a strong correlation with cell yield, testicular volume and serum follicle stimulating hormone (FSH) levels (all p < 0.0001). Excretory and secretory azoospermia corresponded strongly with FNA grades A1 and A2, respectively. FNA grading was predictive of clinical outcome in terms of sperm yield at testicular sperm extraction, fertilization and pregnancy. In our series, FNA of the testis was relatively free of complications; we recommend its use in the routine diagnosis of azoospermia.

Functional and cytologic features of the contralateral testis in cryptorchidism

OBJECTIVE

To characterize the testicular cytologic pictures in cryptorchild and contralateral testis related to seminal pattern.

DESIGN

Controlled clinical study.

SETTING

Andrological and urologic academic setting.

PATIENTS

One hundred nine patients orchidopexied because of unilateral cryptorchidism compared with 35 normospermic subjects.

INTERVENTIONS

Bilateral testicular fine-needle aspiration cytology.

MAIN OUTCOME MEASURES

Seminal parameters; testicular cytologic features; plasma levels of FSH, LH, and T; and ultrasound testicular examination.

RESULTS

The cytologic analysis revealed an important quantitative and qualitative impairment of spermatogenic line in all the excryptorchid testes. These alterations are present in the contralateral testes only when azoospermia or severe oligozoospermia were observed, whereas in moderate oligozoospermic subjects a normal tubular status was evident. A compensatory activity in normally descended testis of normozoospermic patients was present.

CONCLUSIONS

In unilateral cryptorchidism, a frequent testicular damage in the orchidopexied and in the contralateral descended testis suggests that this condition is the end point of different pathological conditions, including testicular intrinsic (congenital) and extrinsic (anatomical) causes. Fine-needle aspiration cytology of both testes represents a tool in the assessment of the tubular status in excryptorchid subjects.

The Contralateral Testis in Cryptorchid Patients

We performed bilateral testicular Fine Needle Aspiration Cytology (FNAC) in a large group of unilateral cryptorchid subjects to characterize the tubular status related to the seminal pattern. In azoospermic and in severe oligozoospermic subjects the cytological picture of the contralateral testis showed similar lesions to those observed in the cryptorchid testis, while in moderate oligozoospermic subjects this analysis revealed the presence of a normal spermatogenic line and in normospermic subjects the presence of a compensatory activity of the tubular function. In conclusion, in unilateral cryptorchidism a frequent testicular damage in the orchidopexied testis and a concomitant tubular alteration in the contralateral scrotal testis exist, suggesting that cryptorchidism is the end point of different pathological conditions, including intrinsic (congenital) and extrinsic (anatomical) causes. FNAC of both testes could represent a tool for the clinician in the assessment of the tubular status in cryptorchid subjects, above all in presence of azoospermia or severe oligozoospermia. In these cases the existence of intratesticular spermatids or mature spermatozoa allows new assisted reproduction techniques using intratesticular germ cells to be used.