A systemic review and meta-analysis exploring the predictors of sperm retrieval in patients with non-obstructive azoospermia and chromosomal abnormalities

Sperm retrieval rate and patient factors in azoospermia factor c microdeletion azoospermia: a systematic review

OBJECTIVE

To reveal the overall sperm retrieval rate (SRR) and range in patients with azoospermia factor c (AZFc) microdeletion azoospermia by microdissection testicular sperm extraction (mTESE) and discuss the differences of preoperative patient factors among studies with various SRRs.

PATIENTS AND METHODS

We searched PubMed, Web of Science and Embase until February 2023. All studies reporting SRRs by mTESE and required parameters of patients with AZFc microdeletions were included. The primary outcome was the SRR and, if available, the pregnancy rate (PR) and live-birth rate (LBR) after intracytoplasmic sperm injection were also investigated as secondary outcomes.

RESULTS

Eventually 11 cohort studies were included in this review. A total number of 441 patients underwent mTESE and in 275 of them sperm was obtained, reaching an overall SRR of 62.4%. The SRRs among studies had a wide range from 25.0% to 85.7%. The studies reporting higher SRRs generally had older mean ages, and higher follicle-stimulating hormone and testosterone levels. Only four studies provided practical data on pregnancies and live-born children of patients with AZFc microdeletions, so the overall PR and LBR were unavailable.

CONCLUSIONS

The overall SRR of patients with AZFc microdeletion azoospermia was 62.4%. The effect of patient factors in SR needs further evidence in future work.

Non-invasive biomarkers for sperm retrieval in non-obstructive patients: a comprehensive review

Recent advancements in reproductive medicine have guided novel strategies for addressing male infertility, particularly in cases of non-obstructive azoospermia (NOA). Two prominent invasive interventions, namely testicular sperm extraction (TESE) and microdissection TESE (micro-TESE), have emerged as key techniques to retrieve gametes for assisted reproduction technologies (ART). Both heterogeneity and complexity of NOA pose a multifaceted challenge to clinicians, as the invasiveness of these procedures and their unpredictable success underscore the need for more precise guidance. Seminal plasma can be aptly regarded as a liquid biopsy of the male reproductive tract, encompassing secretions from the testes, epididymides, seminal vesicles, bulbourethral glands, and prostate. This fluid harbors a variety of cell-free nucleic acids, microvesicles, proteins, and metabolites intricately linked to gonadal activity. However, despite numerous investigations exploring potential biomarkers from seminal fluid, their widespread inclusion into the clinical practice remains limited. This could be partially due to the complex interplay of diverse clinical and genetic factors inherent to NOA that likely contributes to the absence of definitive biomarkers for residual spermatogenesis. It is conceivable that the integration of clinical data with biomarkers could increase the potential in predicting surgical procedure outcomes and their choice in NOA cases. This comprehensive review addresses the challenge of sperm retrieval in NOA through non-invasive biomarkers. Moreover, we delve into promising perspectives, elucidating innovative approaches grounded in multi-omics methodologies, including genomics, transcriptomics and proteomics. These cutting-edge techniques, combined with the clinical and genetics features of patients, could improve the use of biomarkers in personalized medical approaches, patient counseling, and the decision-making continuum. Finally, Artificial intelligence (AI) holds significant potential in the realm of combining biomarkers and clinical data, also in the context of identifying non-invasive biomarkers for sperm retrieval.

Global Practice Patterns in the Evaluation of Non-Obstructive Azoospermia: Results of a World-Wide Survey and Expert Recommendations

PURPOSE

Non-obstructive azoospermia (NOA) represents the persistent absence of sperm in ejaculate without obstruction, stemming from diverse disease processes. This survey explores global practices in NOA diagnosis, comparing them with guidelines and offering expert recommendations.

MATERIALS AND METHODS

A 56-item questionnaire survey on NOA diagnosis and management was conducted globally from July to September 2022. This paper focuses on part 1, evaluating NOA diagnosis. Data from 367 participants across 49 countries were analyzed descriptively, with a Delphi process used for expert recommendations.

RESULTS

Of 336 eligible responses, most participants were experienced attending physicians (70.93%). To diagnose azoospermia definitively, 81.7% requested two semen samples. Commonly ordered hormone tests included serum follicle-stimulating hormone (FSH) (97.0%), total testosterone (92.9%), and luteinizing hormone (86.9%). Genetic testing was requested by 66.6%, with karyotype analysis (86.2%) and Y chromosome microdeletions (88.3%) prevalent. Diagnostic testicular biopsy, distinguishing obstructive azoospermia (OA) from NOA, was not performed by 45.1%, while 34.6% did it selectively. Differentiation relied on physical examination (76.1%), serum hormone profiles (69.6%), and semen tests (68.1%). Expectations of finding sperm surgically were higher in men with normal FSH, larger testes, and a history of sperm in ejaculate.

CONCLUSIONS

This expert survey, encompassing 367 participants from 49 countries, unveils congruence with recommended guidelines in NOA diagnosis. However, noteworthy disparities in practices suggest a need for evidence-based, international consensus guidelines to standardize NOA evaluation, addressing existing gaps in professional recommendations.

The Global Andrology Forum (GAF): Structure, Roles, Functioning and Outcomes: An Online Model for Collaborative Research

PURPOSE

There are no published examples of a global online research collaborative in andrology. We describe the development, profile and member characteristics of the first consortium of this type, the Global Andrology Forum (GAF).

MATERIALS AND METHODS

An online survey sent to all GAF members collected demographic information (sex, age, experience, academic title, degrees, country, specialty, profession). It also tapped data on members' characteristics e.g., skills in research, software and statistics; preferred activities; time commitments; expected roles; and interest in participating in research, in GAF's scientific activities and collaborative online research. The findings were analyzed and tabulated. We outline members' demographic and professional characteristics and scientific achievements to date. A narrative approach outlined GAF's structure and functioning.

RESULTS

A total of 418 out of 540 members completed the survey and were included in the analysis (77.4% response rate). The sample comprised mainly urologists (34.2%) and a third of the respondents had practiced for >15 years (33.3%). Up to 86.1% of the members expressed interest in being actively engaged in writing scientific articles. A third of the sample (37.1%) could dedicate 4 to 6 hours/week. Few respondents reported skills in statistics and artwork (2.6% and 1.9% respectively). Members were assigned to specific roles based on their expertise and experiences. Collaborative working ensured the timely completion of projects while maintaining quality. For outcomes, GAF published 29 original articles within one year of its creation, with authors from 48 countries spanning topics that included varicocele, sperm DNA damage, oxidative stress, semen analysis and male infertility, oocyte/embryo, and laboratory issues of assisted reproductive technique (ART) and male infertility evaluation.

CONCLUSIONS

GAF is a successful global online andrology research model. A healthy number of scientific articles have been published. Given such effectiveness, adopting the GAF model could be useful for other disciplines that wish to create and coordinate successful international online research groups.

Hypergonadotropic hypogonadism and chromosomal aberrations: clinical heterogeneity and implications on the health of elderly men, case series

BACKGROUND

Hypogonadism in older men is often considered as late onset hypogonadism. However, this clinical condition results from primary testicular failure which could be of genetic origin with Klinefelter syndrome being the most common chromosomal abnormality associated with it.

CASE PRESENTATION

We report a heterogeneous group of cases who were diagnosed with hypergonadotropic hypogonadism in their adulthood and were found to have rare chromosomal aberrations. All were elderly men (in their 70 s and 80 s) for whom the diagnosis was made during the evaluation of incidental symptoms suggestive of endocrinopathy. The first had hyponatremia; the other two had gynaecomastia and features of hypogonadism noted during admission for various acute medical problems. With respect to their genetic results; the first had a male karyotype with balanced reciprocal translocation between the long arm of chromosome 4 and the short arm of chromosome 7. The second case had a male karotype with one normal X chromosome and an isochrome for the short arm of the Y chromosome. The third case was an XX male with unbalanced translocation between the X & Y chromosomes with retention of the SRY locus.

CONCLUSION

Hypergonadotrophic hypogonadism in the elderly, may be due to chromosomal aberrations, resulting in heterogeneous and diverse clinical phenotypes. Vigilance must be exercised when seeing cases with subtle clinical findings. This report suggests that in selected cases of adult hypergonadotropic hypogonadism, chromosomal analysis may be indicated.

Individuals with numerical and structural variations of sex chromosomes: interdisciplinary management with focus on fertility potential

Diagnosis and management of individuals who have differences of sex development (DSD) due to numerical or structural variations of sex chromosomes (NSVSC) remains challenging. Girls who have Turner syndrome (45X) may present with varying phenotypic features, from classical/severe to minor, and some remain undiagnosed. Boys and girls who have 45,X/46,XY chromosomal mosaicism may have Turner syndrome-like features and short stature; therefore, unexplained short stature during childhood requires karyotype analysis in both sexes, particularly if characteristic features or atypical genitalia are present. Many individuals with Klinefelter syndrome (47XXY) remain undiagnosed or are only diagnosed as adults due to fertility problems. Newborn screening by heel prick tests could potentially identify sex chromosome variations but would have ethical and financial implications, and in-depth cost-benefit analyses are needed before nationwide screening can be introduced. Most individuals who have NSVSC have lifelong co-morbidities and healthcare should be holistic, personalized and centralized, with a focus on information, psychosocial support and shared decision-making. Fertility potential should be assessed individually and discussed at an appropriate age. Oocyte or ovarian tissue cryopreservation is possible in some women who have Turner syndrome and live births have been reported following assisted reproductive technology (ART). Testicular sperm cell extraction (TESE) is possible in some men who have 45,X/46,XY mosaicism, but there is no established protocol and no reported fathering of children. Some men with Klinefelter syndrome can now father a child following TESE and ART, with multiple reports of healthy live births. Children who have NSVSC, their parents and DSD team members need to address possibilities and ethical questions relating to potential fertility preservation, with guidelines and international studies still needed.

Loss of SUN1 function in spermatocytes disrupts the attachment of telomeres to the nuclear envelope and contributes to non-obstructive azoospermia in humans

One of the most severe forms of infertility in humans, caused by gametogenic failure, is non-obstructive azoospermia (NOA). Approximately, 20-30% of men with NOA may have single-gene mutations or other genetic variables that cause this disease. While a range of single-gene mutations associated with infertility has been identified in prior whole-exome sequencing (WES) studies, current insight into the precise genetic etiology of impaired human gametogenesis remains limited. In this paper, we described a proband with NOA who experienced hereditary infertility. WES analyses identified a homozygous variant in the SUN1 (Sad1 and UNC84 domain containing 1) gene [c. 663C > A: p.Tyr221X] that segregated with infertility. SUN1 encodes a LINC complex component essential for telomeric attachment and chromosomal movement. Spermatocytes with the observed mutations were incapable of repairing double-strand DNA breaks or undergoing meiosis. This loss of SUN1 functionality contributes to significant reductions in KASH5 levels within impaired chromosomal telomere attachment to the inner nuclear membrane. Overall, our results identify a potential genetic driver of NOA pathogenesis and provide fresh insight into the role of the SUN1 protein as a regulator of prophase I progression in the context of human meiosis.

Delaying testicular sperm extraction in 47,XXY Klinefelter patients does not impair the sperm retrieval rate, and AMH levels are higher when TESE is positive

STUDY QUESTION

Should testicular sperm extraction (TESE) in non-mosaic 47,XXY Klinefelter syndrome (KS) patients be performed soon after puberty or could it be delayed until adulthood?

SUMMARY ANSWER

The difference in sperm retrieval rate (SRR) in TESE was not significant between the 'Young' (15-22 years old) cohort and the 'Adult' (23-43 years old) cohort of non-mosaic KS patients recruited prospectively in parallel.

WHAT IS KNOWN ALREADY

Several studies have tried to define predictive factors for TESE outcome in non-mosaic KS patients, with very heterogeneous results. Some authors have found that age was a pejorative factor and recommended performing TESE soon after puberty. To date, no predictive factors have been unanimously recognized to guide clinicians in deciding to perform TESE in azoospermic KS patients.

STUDY DESIGN, SIZE, DURATION

Two cohorts (Young: 15-22 years old; Adult: 23-43 years old) were included prospectively in parallel. A total of 157 non-mosaic 47,XXY KS patients were included between 2010 and 2020 in the reproductive medicine department of the University Hospital of Lyon, France. However 31 patients gave up before TESE, four had cryptozoospermia and three did not have a valid hormone assessment; these were excluded from this study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data for 119 patients (61 Young and 58 Adult) were analyzed. All of these patients had clinical, hormonal and seminal evaluation before conventional TESE (c-TESE).

MAIN RESULTS AND THE ROLE OF CHANCE

The global SRR was 45.4%. SRRs were not significantly different between the two age groups: Young SRR=49.2%, Adult SRR = 41.4%; P = 0.393. Anti-Müllerian hormone (AMH) and inhibin B were significantly higher in the Young group (AMH: P = 0.001, Inhibin B: P < 0.001), and also higher in patients with a positive TESE than in those with a negative TESE (AMH: P = 0.001, Inhibin B: P = 0.036). The other factors did not differ between age groups or according to TESE outcome. AMH had a better predictive value than inhibin B. SRRs were significantly higher in the upper quartile of AMH plasma levels than in the lower quartile (or in cases with AMH plasma level below the quantification limit): 67.7% versus 28.9% in the whole population (P = 0.001), 60% versus 20% in the Young group (P = 0.025) and 71.4% versus 33.3% in the Adult group (P = 0.018).

LIMITATIONS, REASONS FOR CAUTION

c-TESE was performed in the whole study; we cannot rule out the possibility of different results if microsurgical TESE had been performed. Because of the limited sensitivity of inhibin B and AMH assays, a large number of patients had values lower than the quantification limits, preventing the definition a threshold below which negative TESE can be predicted.

WIDER IMPLICATIONS OF THE FINDINGS

In contrast to some studies, age did not appear as a pejorative factor when comparing patients 15-22 and 23-44 years of age. Improved accuracy of inhibin B and AMH assays in the future might still allow discrimination of patients with persistent foci of spermatogenesis and guide clinician decision-making and patient information.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by a grant from the French Ministry of Health D50621 (Programme Hospitalier de Recherche Clinical Régional 2008). The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

NCT01918280.

The predictive factors of successful sperm retrieval for men with Y chromosome AZFc microdeletion

PURPOSE

To identify key predictors for successful sperm retrieval in men with AZFc microdeletion.

METHODS

Totally, 71 infertile men with confirmed AZFc microdeletion were studied. For each patient, the endocrine profile including serum follicle stimulating hormone (FSH), luteinizing hormone, total testosterone, prolactin, and estradiol was recorded, along with intratesticular testosterone levels (ITT), age, and testicular size. The factors were further analyzed to determine the key predictors for successful sperm retrieval.

RESULTS

Of the 71 men with AZFc microdeletion, 52 (73.2%) were classified as having non-obstructive azoospermia (NOA), 7 (9.9%) as having cryptozoospermia, and 12 (15.8%) as having severe oligoasthenoteratozoospermia. Of the 52 men with azoospermia, 47 received microdissection testicular sperm retrieval, and sperm retrieval was successful in 35 of those cases (74.5%). A significantly lower serum FSH (p = 0.03) was found in those patients from whom sperm could be successfully retrieved. The area under the receiving operating characteristic curve for FSH was determined to be 0.721. Using an FSH cutoff point of 12.95 mIU/mL, the model for predicting successful sperm retrieval was found to have 51.4% sensitivity, 83.3% specificity, 90.0% positive predictive value, and 37.0% negative predictive value. ITT levels were obtained from 7 NOA patients, the mean ITT and the mean ITT/serum testosterone ratio was 1932.8 ng/ml and 567.2 in 6 men with successful sperm retrieval, whereas, in a patient with fail sperm retrieval, the levels were 2370 ng/ml and 393.0.

CONCLUSION

Men exhibiting AZFc microdeletion with discernible spermatogenesis from whom sperm was successfully retrieved by mTESE generally presented with relatively lower FSH levels.

Systemic immune-inflammation index, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio are predictors of sperm presence in microdissection testicular sperm extraction

The aim of this study is to evaluate the value of the haematologic inflammatory parameters in predicting sperm retrieval rates during microdissection testicular sperm extraction (micro-TESE).159 patients diagnosed with non-obstructive azoospermia were included in the study. After excluding the patients that do not fit the inclusion criteria, age, smoking status, body-mass index, serum luteinizing hormone, follicle-stimulating hormone, total testosterone levels and neutrophil, lymphocyte and platelet counts were recorded. Neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and systemic immune-inflammation index were calculated. The primary outcome was defined as the presence of spermatozoa during the procedure and the association between the candidate predictors and primary endpoint were evaluated by logistic regression analysis. Then, a baseline model from age, smoking, body-mass index and hormonal levels was built. Ratios and indexes were included, respectively, and were compared by multivariate analyses. Each of all three parameters was an independent predictor of obtaining spermatozoa during micro-TESE procedure (all p < 0.001). Even though all three parameters were significant, neutrophil-lymphocyte ratio and systemic immune-inflammation index stood out as more powerful than platelet-lymphocyte ratio (p < 0.08, p < 0.08 respectively). Additionally, adding these parameters individually to the baseline model significantly empowered the predictive value (all p < 0.001). Using haematologic inflammatory parameters in the prediction of sperm presence during microdissection testicular sperm extraction may be helpful when consulting the patient with having a better foresight of the procedural outcomes.

Nomogram based on a circular RNA biomarker for predicting the likelihood of successful sperm retrieval via microdissection testicular sperm extraction in patients with idiopathic non-obstructive azoospermia

BACKGROUND

Many circular RNAs (circRNAs) are specifically expressed in the testes and seminal plasma of patients with non-obstructive azoospermia (NOA), highlighting them as potential predictors of microdissection testicular sperm extraction (micro-TESE) outcomes. Although research has indicated that circular RNA monoglyceride lipase (circ_MGLL) is highly expressed in the testicular tissues of patients with NOA, the association between circ_MGLL expression and sperm retrieval outcomes (SROs) in patients with idiopathic non-obstructive azoospermia (iNOA) receiving micro-TESE remains unclear.

METHODS

This single-center, retrospective cohort study enrolled 114 patients with iNOA who underwent micro-TESE at Northwest Women's and Children's Hospital from January 2017 to November 2021. A logistic regression model was used to examine associations between SRO and circ_MGLL expression in testicular tissues, the results of which were used in conjunction with previous findings to establish a nomogram. The predictive performance of the circ_MGLL-based nomogram was evaluated via calibration curves, receiver operating characteristic curves, and decision curve analysis (DCA) using an internal validation method.

RESULTS

The generalized additive model indicated that the probability of successful SRO for micro-TESE decreased as circ_MGLL expression increased in testicular tissues. Across the entire cohort, univariate logistic regression analysis revealed that circ_MGLL expression was inversely associated with SRO in patients with NOA. This trend did not change after stratification according to age, body mass index, testicular volume, follicle-stimulating hormone (FSH) level, luteinizing hormone (LH) level, testosterone (T) level, or pathological type (or after adjusting for these confounders) (odds ratio <1, P < 0.001). A nomogram was then generated by integrating circ_MGLL, pathological types, and FSH, LH, and T levels. The circ_MGLL-based predictive model achieved satisfactory discrimination, with an area under the curve of 0.857, and the calibration curves demonstrated impressive agreement. The DCA indicated that the net clinical benefit of the circ_MGLL-based predictive model was greater than that of circ_MGLL alone.

CONCLUSION

circ_MGLL is significantly associated with the SRO of micro-TESE in patients with iNOA. The circ_MGLL-based nomogram developed in the current study can predict successful SRO with high accuracy.