{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T19:07:33Z","timestamp":1789067253160,"version":"build-2803163510"},"reference-count":118,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T00:00:00Z","timestamp":1782950400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Non-obstructive azoospermia (NOA) is characterized by focal and quantitatively limited spermatogenesis, making preoperative prediction of sperm retrieval difficult. Seminal plasma is a biologically plausible liquid-biopsy compartment because it contains testicular, epididymal and accessory-gland secretions enriched with extracellular vesicles, cell-free nucleic acids, proteins and metabolites. This narrative molecular review examines the mechanisms by which germ-cell-derived molecular cargo reaches the ejaculate and organizes seminal-plasma biomarkers by cargo class and spermatogenic stage. Particular attention is given to extracellular-vesicle non-coding RNAs, cell-free seminal mRNAs, germ-cell-enriched proteins including TEX101 and ECM1, and metabolomic and lipidomic signatures. Although several markers show promising discrimination, most remain discovery-stage, single-center and insufficiently validated. The central argument is that the field should move from isolated biomarker nomination toward locked, stage-mapped multi-analyte panels integrated with clinical and genetic predictors under modern prediction-model standards. Seminal plasma is best viewed not as a ready clinical test, but as a biologically coherent platform for future calibrated, externally validated and artificial-intelligence (AI)-ready sperm-retrieval decision support.<\/jats:p>","DOI":"10.3390\/ijms27135965","type":"journal-article","created":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T15:52:24Z","timestamp":1783007544000},"page":"5965","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Seminal-Plasma Molecular Biomarkers as a Liquid Biopsy of Testicular Function: Toward AI-Ready Sperm-Retrieval Prediction in Non-Obstructive Azoospermia"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4651-312X","authenticated-orcid":false,"given":"Aris","family":"Kaltsas","sequence":"first","affiliation":[{"name":"Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fotios","family":"Gasparos","sequence":"additional","affiliation":[{"name":"Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-5811-8474","authenticated-orcid":false,"given":"Andreas","family":"Koumenis","sequence":"additional","affiliation":[{"name":"Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marios","family":"Stavropoulos","sequence":"additional","affiliation":[{"name":"Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Chrisofos","sequence":"additional","affiliation":[{"name":"Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e28218","DOI":"10.4161\/spmg.28218","article-title":"Review of Azoospermia","volume":"4","author":"Wosnitzer","year":"2014","journal-title":"Spermatogenesis"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3000605211002703","DOI":"10.1177\/03000605211002703","article-title":"Predictors of testicular sperm retrieval in patients with non-obstructive azoospermia: A review","volume":"49","author":"Qi","year":"2021","journal-title":"J. Int. Med. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"365","DOI":"10.4103\/aja202436","article-title":"Clinical predictors of successful outcomes for couples with nonobstructive azoospermic male partners undergoing micro-TESE","volume":"27","author":"Kavoussi","year":"2024","journal-title":"Asian J. Androl."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1099\u20131103.e1\u20133","DOI":"10.1016\/j.fertnstert.2015.07.1136","article-title":"Comparison of microdissection testicular sperm extraction, conventional testicular sperm extraction, and testicular sperm aspiration for nonobstructive azoospermia: A systematic review and meta-analysis","volume":"104","author":"Bernie","year":"2015","journal-title":"Fertil. Steril."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1093\/humupd\/dmx008","article-title":"Sperm recovery and ICSI outcomes in Klinefelter syndrome: A systematic review and meta-analysis","volume":"23","author":"Corona","year":"2017","journal-title":"Hum. Reprod. Update"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Krausz, C., and Cioppi, F. (2021). Genetic factors of non-obstructive azoospermia: Consequences on patients\u2019 and offspring health. J. Clin. Med., 10.","DOI":"10.3390\/jcm10174009"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.euros.2024.05.001","article-title":"Role of Follicle-stimulating Hormone, Inhibin B, and Anti-M\u00fcllerian Hormone in Predicting Sperm Retrieval from Men with Nonobstructive Azoospermia Undergoing Microdissection Testicular Sperm Extraction: A Systematic Review and Meta-analysis","volume":"65","author":"Pozzi","year":"2024","journal-title":"Eur. Urol. Open Sci."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Kaltsas, A., Stavros, S., Kratiras, Z., Zikopoulos, A., Machairiotis, N., Potiris, A., Dimitriadis, F., Sofikitis, N., Chrisofos, M., and Zachariou, A. (2024). Predictors of Successful Testicular Sperm Extraction: A New Era for Men with Non-Obstructive Azoospermia. Biomedicines, 12.","DOI":"10.3390\/biomedicines12122679"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1186\/s12958-018-0358-6","article-title":"The enigmatic seminal plasma: A proteomics insight from ejaculation to fertilization","volume":"16","author":"Samanta","year":"2018","journal-title":"Reprod. Biol. Endocrinol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3607","DOI":"10.1016\/j.sjbs.2021.03.038","article-title":"Seminal exosomes\u2014An important biological marker for various disorders and syndrome in human reproduction","volume":"28","author":"Vickram","year":"2021","journal-title":"Saudi J. Biol. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1186\/s12610-023-00184-0","article-title":"Seminal plasma biomarkers for predicting successful sperm retrieval in patients with nonobstructive azoospermia: A narrative review of human studies","volume":"33","author":"Li","year":"2023","journal-title":"Basic. Clin. Androl."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1093\/biolre\/ioz088","article-title":"What has single-cell RNA-seq taught us about mammalian spermatogenesis?","volume":"101","author":"Suzuki","year":"2019","journal-title":"Biol. Reprod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"564","DOI":"10.1210\/er.2014-1101","article-title":"The Mammalian Blood-Testis Barrier: Its Biology and Regulation","volume":"36","author":"Mruk","year":"2015","journal-title":"Endocr. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1530\/REP-10-0232","article-title":"Apoptosis in the germ line","volume":"141","author":"Aitken","year":"2010","journal-title":"Reproduction"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1038\/nrm.2017.125","article-title":"Shedding light on the cell biology of extracellular vesicles","volume":"19","author":"Raposo","year":"2018","journal-title":"Nat. Rev. Mol. Cell Biol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2980","DOI":"10.1038\/ncomms3980","article-title":"Sumoylated hnRNPA2B1 controls the sorting of miRNAs into exosomes through binding to specific motifs","volume":"4","author":"Mittelbrunn","year":"2013","journal-title":"Nat. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Choy, K.H.K., Chan, S.Y., Lam, W., Jin, J., Zheng, T., Law, T.Y.S., Yu, S.S., Wang, W., Li, L., and Xie, G. (2022). The repertoire of testicular extracellular vesicle cargoes and their involvement in inter-compartmental communication associated with spermatogenesis. BMC Biol., 20.","DOI":"10.1186\/s12915-022-01268-5"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1093\/humrep\/dead015","article-title":"The emerging role of extracellular vesicles in the testis","volume":"38","author":"Ma","year":"2023","journal-title":"Hum. Reprod."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5003","DOI":"10.1073\/pnas.1019055108","article-title":"Argonaute2 complexes carry a population of circulating microRNAs independent of vesicles in human plasma","volume":"108","author":"Arroyo","year":"2011","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1016\/0167-4838(84)90049-9","article-title":"A ribonuclease from human seminal plasma active on double-stranded RNA","volume":"788","author":"Sorrentino","year":"1984","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Li, H., Huang, S., Guo, C., Guan, H., and Xiong, C. (2012). Cell-free seminal mRNA and microRNA exist in different forms. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0034566"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"7290","DOI":"10.1093\/nar\/gku347","article-title":"Exosomes in human semen carry a distinctive repertoire of small non-coding RNAs with potential regulatory functions","volume":"42","author":"Vojtech","year":"2014","journal-title":"Nucleic Acids Res."},{"key":"ref_23","first-page":"668","article-title":"Experimental validation of seminal miR-31-5p as biomarker for azoospermia and evaluation of the effect of preanalytical variables","volume":"11","author":"Bassas","year":"2022","journal-title":"Andrology"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"5683","DOI":"10.1038\/s41467-020-19414-4","article-title":"Single-cell analysis of developing and azoospermia human testicles reveals central role of Sertoli cells","volume":"11","author":"Zhao","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1016\/j.freeradbiomed.2025.08.061","article-title":"Single-cell, spatial and bulk transcriptome data analysis revealed LINC00467-mediated Sertoli cell ferroptosis is a potential therapeutic target and biomarker for azoospermia","volume":"240","author":"Bo","year":"2025","journal-title":"Free Radic. Biol. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1038\/s41585-023-00837-9","article-title":"Molecular mechanisms of cellular dysfunction in testes from men with non-obstructive azoospermia","volume":"21","author":"Piechka","year":"2023","journal-title":"Nat. Rev. Urol."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Kaltsas, A., Kyrgiafini, M.A., Mamuris, Z., Chrisofos, M., and Sofikitis, N. (2026). Spermatogenesis Beyond DNA: Integrated RNA Control of the Epitranscriptome and Three-Dimensional Genome Architecture. Curr. Issues Mol. Biol., 48.","DOI":"10.3390\/cimb48010123"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Kyrgiafini, M.A., Kaltsas, A., Chatziparasidou, A., and Mamuris, Z. (2025). The Small RNA Landscape in Azoospermia: Implications for Male Infertility and Sperm Retrieval-A Preliminary Study. Int. J. Mol. Sci., 26.","DOI":"10.3390\/ijms26083537"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"e13892","DOI":"10.1111\/aji.13892","article-title":"Construction of m6A-Related Gene Prediction Model and Subtype Analysis in Non-Obstructive Azoospermia Based on Bioinformatics","volume":"92","author":"Li","year":"2024","journal-title":"Am. J. Reprod. Immunol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1111\/j.2517-6161.1996.tb02080.x","article-title":"Regression shrinkage and selection via the lasso","volume":"58","author":"Tibshirani","year":"1996","journal-title":"J. R. Stat. Soc. Ser. B Stat. Methodol."},{"key":"ref_31","first-page":"2","article-title":"Testicular biopsy score count\u2014A method for registration of spermatogenesis in human testes: Normal values and results in 335 hypogonadal males","volume":"1","author":"Johnsen","year":"1970","journal-title":"Hormones"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1242\/bio.201410959","article-title":"mir-34b\/c and mir-449a\/b\/c are required for spermatogenesis, but not for the first cleavage division in mice","volume":"4","author":"Yuan","year":"2015","journal-title":"Biol. Open"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1093\/humrep\/dey072","article-title":"Exosomal microRNAs in seminal plasma are markers of the origin of azoospermia and can predict the presence of sperm in testicular tissue","volume":"33","author":"Mata","year":"2018","journal-title":"Hum. Reprod."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.omtn.2018.11.004","article-title":"miRNA-31-5p mediates the proliferation and apoptosis of human spermatogonial stem cells via targeting JAZF1 and cyclin A2","volume":"14","author":"Fu","year":"2018","journal-title":"Mol. Ther. Nucleic Acids"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"392","DOI":"10.21037\/atm-21-5100","article-title":"Circulating microRNAs in seminal plasma as predictors of sperm retrieval in microdissection testicular sperm extraction","volume":"10","author":"Zhang","year":"2022","journal-title":"Ann. Transl. Med."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Willems, M., Devriendt, C., Olsen, C., Caljon, B., Janssen, T., Gies, I., Vloeberghs, V., Tournaye, H., Van Saen, D., and Goossens, E. (2023). Micro RNA in Semen\/Urine from Non-Obstructive Azoospermia Patients as Biomarkers to Predict the Presence of Testicular Spermatozoa and Spermatogonia. Life, 13.","DOI":"10.3390\/life13030616"},{"key":"ref_37","unstructured":"Babakhanzadeh, E., Khodadadian, A., Esmaeili Dahaj, F., Hakimi, F., Nazari, M., Mozhdeh, M., Vahidi Mehrgardi, S., Jafari, M.H., Dehghani, M., and Ghafouri-Fard, S. (2026). Uncovering hidden spermatogenesis: INPP1 and GTSF1 as non-invasive predictors of sperm retrieval in non-obstructive azoospermia. Sci. Rep., Epub ahead of print."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"591","DOI":"10.4103\/1008-682X.185001","article-title":"MicroRNA-27a-mediated repression of cysteine-rich secretory protein 2 translation in asthenoteratozoospermic patients","volume":"19","author":"Zhou","year":"2017","journal-title":"Asian J. Androl."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"961","DOI":"10.18502\/ijrm.v13i11.7963","article-title":"hsa-miR-27a-3p overexpression in men with nonobstructive azoospermia: A case-control study","volume":"18","author":"Norioun","year":"2020","journal-title":"Int. J. Reprod. Biomed."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"5935","DOI":"10.1007\/s11033-021-06593-6","article-title":"Pro-inflammatory cytokines and microRNAs in male infertility","volume":"48","author":"Attia","year":"2021","journal-title":"Mol. Biol. Rep."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2413","DOI":"10.1093\/humrep\/deaa184","article-title":"A panel of extracellular vesicle long noncoding RNAs in seminal plasma for predicting testicular spermatozoa in nonobstructive azoospermia patients","volume":"35","author":"Xie","year":"2020","journal-title":"Hum. Reprod."},{"key":"ref_42","first-page":"246","article-title":"Seminal Plasma ExLncRNA Pairs: Updating Perspectives in the Search for Testicular Spermatozoa Retrieval Biomarkers in Nonobstructive Azoospermia Patients with mTESE by WGCNA","volume":"20","author":"Cao","year":"2023","journal-title":"Urol. J."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Abdallah, H.Y., Hosny, N., Ahmed, N., and Ismail, E.A. (2026). Seminal long non-coding RNAs as prognostic non-invasive biomarkers in non-obstructive azoospermia. BMC Med. Genom., 19.","DOI":"10.1186\/s12920-025-02207-3"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2649","DOI":"10.1093\/humrep\/deab196","article-title":"Potential of testis-derived circular RNAs in seminal plasma to predict the outcome of microdissection testicular sperm extraction in patients with idiopathic non-obstructive azoospermia","volume":"36","author":"Ji","year":"2021","journal-title":"Hum. Reprod."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1751","DOI":"10.1111\/andr.13617","article-title":"A detection model of testis-derived circular RNAs in serum for predicting testicular sperm retrieval rate in non-obstructive azoospermia patients","volume":"12","author":"Lv","year":"2024","journal-title":"Andrology"},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Shi, S., Wang, T., Wang, L., and Wang, M. (2023). Nomogram based on a circular RNA biomarker for predicting the likelihood of successful sperm retrievalmicrodissection testicular sperm extraction in patients with idiopathic non-obstructive azoospermia. Front. Endocrinol., 13.","DOI":"10.3389\/fendo.2022.1109807"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1834","DOI":"10.1111\/andr.12874","article-title":"Over-expression of hsa_circ_0000116 in patients with non-obstructive azoospermia and its predictive value in testicular sperm retrieval","volume":"8","author":"Lv","year":"2020","journal-title":"Andrology"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"6637","DOI":"10.1038\/s41467-024-50930-9","article-title":"Inherited defects of piRNA biogenesis cause transposon de-repression, impaired spermatogenesis, and human male infertility","volume":"15","author":"Stallmeyer","year":"2024","journal-title":"Nat. Commun."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1429","DOI":"10.1007\/s10815-021-02101-8","article-title":"Outcome prediction of microdissection testicular sperm extraction based on extracellular vesicles piRNAs","volume":"38","author":"Chen","year":"2021","journal-title":"J. Assist. Reprod. Genet."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1186\/s12958-022-00978-3","article-title":"Seminal plasma extracellular vesicles tRF-Val-AAC-010 can serve as a predictive factor of successful microdissection testicular sperm extraction in patients with non-obstructive azoospermia","volume":"20","author":"Han","year":"2022","journal-title":"Reprod. Biol. Endocrinol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1016\/j.fertnstert.2021.11.010","article-title":"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","volume":"117","author":"Zhang","year":"2021","journal-title":"Fertil. Steril."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1093\/humrep\/der481","article-title":"A novel application of cell-free seminal mRNA: Non-invasive identification of the presence of germ cells or complete obstruction in men with azoospermia","volume":"27","author":"Li","year":"2012","journal-title":"Hum. Reprod."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"31418","DOI":"10.1074\/jbc.M110.116418","article-title":"Zmynd15 encodes a histone deacetylase-dependent transcriptional repressor essential for spermiogenesis and male fertility","volume":"285","author":"Yan","year":"2010","journal-title":"J. Biol. Chem."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"2620","DOI":"10.1093\/humrep\/deu261","article-title":"ESX1 mRNA expression in seminal fluid is an indicator of residual spermatogenesis in non-obstructive azoospermic men","volume":"29","author":"Pansa","year":"2014","journal-title":"Hum. Reprod."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1398","DOI":"10.1093\/humrep\/deq074","article-title":"ESX1 gene expression as a robust marker of residual spermatogenesis in azoospermic men","volume":"25","author":"Bonaparte","year":"2010","journal-title":"Hum. Reprod."},{"key":"ref_56","first-page":"e13483","article-title":"Could analysis of testis-specific genes, as biomarkers in seminal plasma, predict presence of focal spermatogenesis in non-obstructive azoospermia?","volume":"52","author":"Hashemi","year":"2019","journal-title":"Andrologia"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1111\/andr.13173","article-title":"Multi-stage screening cell-free seminal mRNAs to diagnose completion of meiosis and predict testicular sperm retrieval in men with non-obstructive azoospermia","volume":"10","author":"Dai","year":"2022","journal-title":"Andrology"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1093\/molehr\/gah169","article-title":"Cellular expression of protamine 1 and 2 transcripts in testicular spermatids from azoospermic men submitted to TESE-ICSI","volume":"11","author":"Mitchell","year":"2005","journal-title":"Mol. Hum. Reprod."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"e74","DOI":"10.5534\/wjmh.250156","article-title":"Seminal Immature Germ Cells as a Predictor of Microdissection Testicular Sperm Extraction for Development of a Combined Predictive Model","volume":"43","author":"Liu","year":"2025","journal-title":"World J. Mens Health"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"212ra160","DOI":"10.1126\/scitranslmed.3006260","article-title":"Differential diagnosis of azoospermia with proteomic biomarkers ECM1 and TEX101 quantified in seminal plasma","volume":"5","author":"Drabovich","year":"2013","journal-title":"Sci. Transl. Med."},{"key":"ref_61","doi-asserted-by":"crossref","unstructured":"Korbakis, D., Schiza, C., Brinc, D., Soosaipillai, A., Karakosta, T.D., L\u00e9gar\u00e9, C., Sullivan, R., Mullen, B., Jarvi, K., and Diamandis, E.P. (2017). Preclinical evaluation of a TEX101 protein ELISA test for the differential diagnosis of male infertility. BMC Med., 15.","DOI":"10.1186\/s12916-017-0817-5"},{"key":"ref_62","doi-asserted-by":"crossref","unstructured":"Fietz, D., Sgaier, R., O\u2019Donnell, L., Stanton, P.G., Dagley, L.F., Webb, A.I., Schuppe, H.C., Diemer, T., and Pilatz, A. (2024). Proteomic biomarkers in seminal plasma as predictors of reproductive potential in azoospermic men. Front. Endocrinol., 15.","DOI":"10.3389\/fendo.2024.1327800"},{"key":"ref_63","first-page":"1073","article-title":"Evaluation of PGK2 and ACR proteins in seminal plasma: Suggestion of potential new biomarkers for prediction of sperm retrieval in non-obstructive azoospermia patients","volume":"26","author":"Kabodmehri","year":"2022","journal-title":"Hum. Fertil."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1111\/j.2047-2927.2012.00059.x","article-title":"Comparative proteomic analysis coupled with conventional protein assay as a strategy to identify predictors of successful testicular sperm extraction in patients with non-obstructive azoospermia","volume":"1","author":"Freour","year":"2013","journal-title":"Andrology"},{"key":"ref_65","first-page":"257","article-title":"Estimation of Serum and Seminal Plasma Levels of Glactin-1 in Non-Obstructive Azoospermia Cases and Their Correlations with the Rate of Sperm Retrieval: A Comparative Prospective Study","volume":"23","author":"Din","year":"2022","journal-title":"J. Reprod. Infertil."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"1100","DOI":"10.1016\/j.fertnstert.2004.12.010","article-title":"Expression levels of the inhibitor of apoptosis survivin in testes of patients with normal spermatogenesis and spermatogenic failure","volume":"83","author":"Weikert","year":"2005","journal-title":"Fertil. Steril."},{"key":"ref_67","first-page":"96","article-title":"Seminal angiotensin II as a predictive factor of spermatogenic activity in non-obstructive azoospermia","volume":"23","author":"Abdelmeniem","year":"2025","journal-title":"Rev. Int. Androl."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1016\/j.fertnstert.2007.03.032","article-title":"Significance of inhibin B and anti-M\u00fcllerian hormone in seminal plasma: A preliminary study","volume":"89","author":"Duvilla","year":"2007","journal-title":"Fertil. Steril."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"2049","DOI":"10.1007\/s10815-021-02176-3","article-title":"Hormonal markers as noninvasive predictors of sperm retrieval in non-obstructive azoospermia","volume":"38","author":"Zarezadeh","year":"2021","journal-title":"J. Assist. Reprod. Genet."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"2147","DOI":"10.1016\/j.fertnstert.2009.11.046","article-title":"Seminal plasma levels of anti-M\u00fcllerian hormone and inhibin B are not predictive of testicular sperm retrieval in nonobstructive azoospermia: A study of 139 men","volume":"94","author":"Mitchell","year":"2010","journal-title":"Fertil. Steril."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"e14419","DOI":"10.1111\/and.14419","article-title":"Systemic immune-inflammation index, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio are predictors of sperm presence in microdissection testicular sperm extraction","volume":"54","author":"Bastug","year":"2022","journal-title":"Andrologia"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"e3931","DOI":"10.1002\/bmc.3931","article-title":"Untargeted metabolomic profiling of seminal plasma in nonobstructive azoospermia men: A noninvasive detection of spermatogenesis","volume":"31","author":"Gilany","year":"2017","journal-title":"Biomed. Chromatogr."},{"key":"ref_73","doi-asserted-by":"crossref","unstructured":"Aleksandrov, A., Rimskaya, E., Gorevoy, A., Lobanova, N., Borisova, N., Makarova, N., Chernyshev, V., Gorin, D., and Sukhikh, G. (2026). Testicular sperm extraction prediction for patients with non-obstructive azoospermia by Raman spectroscopy. F S Sci., in press.","DOI":"10.1016\/j.xfss.2026.05.001"},{"key":"ref_74","doi-asserted-by":"crossref","unstructured":"Cheng, J., Tang, Y., Zhao, Q., Weng, J., Fang, Z., Qi, Y., Jiang, H., and Zhang, Z. (2026). Seminal Plasma Metabolomic Profiling Reveals Key Metabolic Signatures Linked to Spermatogenic Potential in Non-Obstructive Azoospermia with Cryptorchidism. Metabolites, 16.","DOI":"10.3390\/metabo16020147"},{"key":"ref_75","doi-asserted-by":"crossref","unstructured":"Kaltsas, A., Zikopoulos, A., Markou, E., Zachariou, A., Stavropoulos, M., Kratiras, Z., Symeonidis, E.N., Dimitriadis, F., Sofikitis, N., and Chrisofos, M. (2024). Proteomics and Metabolomics in Varicocele-Associated Male Infertility: Advancing Precision Diagnostics and Therapy. J. Clin. Med., 13.","DOI":"10.3390\/jcm13237390"},{"key":"ref_76","doi-asserted-by":"crossref","unstructured":"Kaltsas, A. (2023). Oxidative Stress and Male Infertility: The Protective Role of Antioxidants. Medicina, 59.","DOI":"10.3390\/medicina59101769"},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"452","DOI":"10.1016\/j.eururo.2022.05.011","article-title":"Genetic Architecture of Azoospermia-Time to Advance the Standard of Care","volume":"83","author":"Wyrwoll","year":"2022","journal-title":"Eur. Urol."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"377","DOI":"10.4103\/jhrs.jhrs_145_22","article-title":"Assessment of the impact induced by different incubation time, storage time, storage medium and thawing methods on sperm DNA fragmentation assay: A before-after study","volume":"15","author":"Sabbaghian","year":"2022","journal-title":"J. Hum. Reprod. Sci."},{"key":"ref_79","first-page":"100350","article-title":"Effect of incubation and analysis temperatures on sperm kinematics and morphometrics during human semen analysis","volume":"21","author":"Navarro","year":"2023","journal-title":"Rev. Int. Androl."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"1535750","DOI":"10.1080\/20013078.2018.1535750","article-title":"Minimal information for studies of extracellular vesicles 2018 (MISEV2018): A position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines","volume":"7","author":"Witwer","year":"2018","journal-title":"J. Extracell. Vesicles"},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"e12404","DOI":"10.1002\/jev2.12404","article-title":"Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches","volume":"13","author":"Welsh","year":"2024","journal-title":"J. Extracell. Vesicles"},{"key":"ref_82","doi-asserted-by":"crossref","unstructured":"Russo, G.I., Asmundo, M.G., Cocci, A., Abdelhameed, A.S., Liprino, A., Giacone, F., Lombardo, D., Guglielmino, A., and Chamayou, S. (2025). Ejaculatory abstinence duration impacts semen parameters: Insights from a retrospective analysis in male infertility on 23,527 analyses. Front. Endocrinol., 16.","DOI":"10.3389\/fendo.2025.1529262"},{"key":"ref_83","first-page":"682","article-title":"The short abstinence may have paradoxical effects on sperms with different level of DNA integrity: A prospective study","volume":"18","author":"Vahidi","year":"2021","journal-title":"Urol. J."},{"key":"ref_84","doi-asserted-by":"crossref","unstructured":"Li, Y., Wang, S., Li, D., Huang, Y., Liu, H., Zhang, X., Qin, J., Mao, X., Li, Z., and Chen, L. (2023). Short-interval second ejaculation improves sperm quality, blastocyst formation in oligoasthenozoospermic males in ICSI cycles: A time-lapse sibling oocytes study. Front. Endocrinol., 14.","DOI":"10.3389\/fendo.2023.1250663"},{"key":"ref_85","unstructured":"World Health Organization (2021). WHO Laboratory Manual for the Examination and Processing of Human Semen, World Health Organization. [6th ed.]."},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"102101","DOI":"10.1016\/j.jogoh.2021.102101","article-title":"Relationship between nuclear DNA fragmentation, mitochondrial DNA damage and standard sperm parameters in spermatozoa of infertile patients with leukocytospermia","volume":"50","author":"Derbel","year":"2021","journal-title":"J. Gynecol. Obstet. Hum. Reprod."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"848","DOI":"10.1111\/andr.12074","article-title":"Differential expression of novel biomarkers (TLR-2, TLR-4, COX-2, and Nrf-2) of inflammation and oxidative stress in semen of leukocytospermia patients","volume":"3","author":"Hagan","year":"2015","journal-title":"Andrology"},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1111\/andr.12886","article-title":"The semen microbiome and its impact on sperm function and male fertility: A systematic review and meta-analysis","volume":"9","author":"Farahani","year":"2021","journal-title":"Andrology"},{"key":"ref_89","doi-asserted-by":"crossref","unstructured":"Magill, R.G., and MacDonald, S.M. (2023). Male infertility and the human microbiome. Front. Reprod. Health, 5.","DOI":"10.3389\/frph.2023.1166201"},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1093\/humrep\/deq337","article-title":"Prediction of sperm retrieval in men with non-obstructive azoospermia using artificial neural networks: Leptin is a good assistant diagnostic marker","volume":"26","author":"Ma","year":"2010","journal-title":"Hum. Reprod."},{"key":"ref_91","doi-asserted-by":"crossref","first-page":"2354","DOI":"10.1097\/01.ju.0000125272.03182.c3","article-title":"An artificial neural network for predicting the presence of spermatozoa in the testes of men with nonobstructive azoospermia","volume":"171","author":"Samli","year":"2004","journal-title":"J. Urol."},{"key":"ref_92","first-page":"53","article-title":"Impact of age, follicle stimulating hormone and Johnsen\u2019s score on successful sperm retrieval by microdissection testicular sperm extraction","volume":"4","author":"Tsujimura","year":"2005","journal-title":"Reprod. Med. Biol."},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"638","DOI":"10.1016\/j.juro.2012.09.038","article-title":"A comparison of models for predicting sperm retrieval before microdissection testicular sperm extraction in men with nonobstructive azoospermia","volume":"189","author":"Ramasamy","year":"2012","journal-title":"J. Urol."},{"key":"ref_94","doi-asserted-by":"crossref","first-page":"1934","DOI":"10.1093\/humrep\/dew147","article-title":"Prediction model for obtaining spermatozoa with testicular sperm extraction in men with non-obstructive azoospermia","volume":"31","author":"Cissen","year":"2016","journal-title":"Hum. Reprod."},{"key":"ref_95","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.urology.2024.10.038","article-title":"A Nomogram Predicting Testicular Sperm Extraction Success in Men With Non-obstructive Azoospermia: A Multi-center Study","volume":"196","author":"Ceyhan","year":"2024","journal-title":"Urology"},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"1202","DOI":"10.1111\/andr.70111","article-title":"Development of a nomogram for sperm retrieval at microTESE for idiopathic non-obstructive azoospermia in a multi-center cohort study","volume":"14","author":"Russo","year":"2025","journal-title":"Andrology"},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"598","DOI":"10.4103\/aja2022111","article-title":"Development of a predictive model for increasing sperm retrieval success by microdissection testicular sperm extraction in patients with nonobstructive azoospermia","volume":"25","author":"Deng","year":"2023","journal-title":"Asian J. Androl."},{"key":"ref_98","doi-asserted-by":"crossref","first-page":"366","DOI":"10.1007\/s43032-023-01362-1","article-title":"A Prediction Model of Sperm Retrieval in Males with Idiopathic Non-obstructive Azoospermia for Microdissection Testicular Sperm Extraction","volume":"31","author":"Zheng","year":"2023","journal-title":"Reprod. Sci."},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"112","DOI":"10.21037\/tau-24-531","article-title":"Development of a predictive nomogram for testicular sperm extraction outcomes in patients with non-obstructive azoospermia using testicular volume, follicle-stimulating hormone levels, and testosterone levels as key parameters","volume":"14","author":"Zhou","year":"2025","journal-title":"Transl. Androl. Urol."},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1111\/andr.70114","article-title":"Machine learning-based personalized prediction of sperm retrieval in patients with non-obstructive azoospermia prior to microdissection testicular sperm extraction: A multi-center cohort study","volume":"14","author":"Xi","year":"2025","journal-title":"Andrology"},{"key":"ref_101","doi-asserted-by":"crossref","unstructured":"Hazir, B., Sahin, A., Gultekin, M.H., Ozer, C., Kayra, M.V., Hasirci, E., Ceyhan, E., Altan, M., Cicek, T., and Kizilkan, Y. (2026). Predicting sperm retrieval success in salvage testicular sperm extraction: A machine learning perspective. Int. J. Impot. Res., 1\u20139. Epub ahead of print.","DOI":"10.1038\/s41443-026-01291-y"},{"key":"ref_102","doi-asserted-by":"crossref","first-page":"4903","DOI":"10.21037\/qims-24-26","article-title":"Testicular ultrasonic microvascular density in assessing spermatogenesis and predicting successful sperm retrieval","volume":"14","author":"Cui","year":"2024","journal-title":"Quant. Imaging Med. Surg."},{"key":"ref_103","doi-asserted-by":"crossref","first-page":"1481","DOI":"10.1111\/andr.13005","article-title":"Evaluation of the potential role of shear wave elastography as a promising predictor of sperm retrieval in non-obstructive azoospermic patients: A prospective study","volume":"9","author":"Abdelaal","year":"2021","journal-title":"Andrology"},{"key":"ref_104","doi-asserted-by":"crossref","first-page":"e14588","DOI":"10.1111\/and.14588","article-title":"Preoperative testosterone and follicle stimulating hormone levels are important predictors for sperm retrieval by microdissection testicular sperm extraction in non-mosaic Klinefelter syndrome","volume":"54","author":"Uemura","year":"2022","journal-title":"Andrologia"},{"key":"ref_105","doi-asserted-by":"crossref","first-page":"e12936","DOI":"10.1111\/and.12936","article-title":"Testicular sperm extraction after laparoscopic orchiectomy for bilateral postpubertal intra-abdominal cryptorchidism: What chance of sperm retrieval?","volume":"50","author":"Cito","year":"2017","journal-title":"Andrologia"},{"key":"ref_106","doi-asserted-by":"crossref","unstructured":"Kaltsas, A., Markou, E., Zachariou, A., Dimitriadis, F., Symeonidis, E.N., Zikopoulos, A., Mamoulakis, C., Tien, D.M.B., Takenaka, A., and Sofikitis, N. (2023). Evaluating the Predictive Value of Diagnostic Testicular Biopsy for Sperm Retrieval Outcomes in Men with Non-Obstructive Azoospermia. J. Pers. Med., 13.","DOI":"10.3390\/jpm13091362"},{"key":"ref_107","doi-asserted-by":"crossref","first-page":"22148","DOI":"10.1038\/s41598-025-03312-0","article-title":"Impact of AZFc deletion subtypes on sperm retrieval rates via micro-TESE and ICSI outcomes in non-obstructive azoospermia patients","volume":"15","author":"Xia","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_108","doi-asserted-by":"crossref","first-page":"433","DOI":"10.3349\/ymj.2023.0054","article-title":"Testosterone to Luteinizing Hormone Ratio as a Potential Predictor of Sperm Retrieval in Non-Obstructive Azoospermia Patients","volume":"64","author":"Kim","year":"2023","journal-title":"Yonsei Med. J."},{"key":"ref_109","doi-asserted-by":"crossref","first-page":"e082505","DOI":"10.1136\/bmj-2024-082505","article-title":"PROBAST+AI: An updated quality, risk of bias, and applicability assessment tool for prediction models using regression or artificial intelligence methods","volume":"388","author":"Moons","year":"2025","journal-title":"BMJ"},{"key":"ref_110","doi-asserted-by":"crossref","first-page":"e078378","DOI":"10.1136\/bmj-2023-078378","article-title":"TRIPOD+AI statement: Updated guidance for reporting clinical prediction models that use regression or machine learning methods","volume":"385","author":"Collins","year":"2024","journal-title":"BMJ"},{"key":"ref_111","first-page":"593","article-title":"The Effects of Varicocele Repair on Testicular Sperm Retrieval, Sperm Recovery in the Ejaculate and Clinical Pregnancy Rates in Non-Obstructive Azoospermic Men with Clinical Varicocele: A Systematic Review and Meta-analysis","volume":"44","author":"Pinggera","year":"2025","journal-title":"World J. Men\u2019s Health"},{"key":"ref_112","doi-asserted-by":"crossref","unstructured":"Kaltsas, A., Dimitriadis, F., Chrisofos, M., Sofikitis, N., and Zachariou, A. (2024). Predictive Value of Varicocele Grade and Histopathology in Simultaneous Varicocelectomy and Sperm Retrieval in Non-Obstructive Azoospermia: A Retrospective Cohort Study. Medicina, 60.","DOI":"10.3390\/medicina60122056"},{"key":"ref_113","doi-asserted-by":"crossref","unstructured":"Zachariou, A., Zikopoulos, A., Markou, E., Koukos, S., Daligaros, G., Skouros, S., Dimitriadis, F., Chrisofos, M., Sofikitis, N., and Kaltsas, A. (2026). Fertility Outcomes in Men with Nonobstructive Azoospermia Due to Hypogonadotropic Hypogonadism After Gonadotropin Therapy. J. Clin. Med., 15.","DOI":"10.3390\/jcm15031204"},{"key":"ref_114","doi-asserted-by":"crossref","first-page":"1442","DOI":"10.21037\/tau.2020.03.35","article-title":"Histology and sperm retrieval among men with Y chromosome microdeletions","volume":"10","author":"Yuen","year":"2021","journal-title":"Transl. Androl. Urol."},{"key":"ref_115","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1186\/s12958-025-01497-7","article-title":"Genetic and epigenetic insights into non-obstructive azoospermia: Mechanisms, biomarkers, and clinical perspectives","volume":"23","author":"Wang","year":"2025","journal-title":"Reprod. Biol. Endocrinol."},{"key":"ref_116","doi-asserted-by":"crossref","first-page":"103910","DOI":"10.1016\/j.rbmo.2024.103910","article-title":"Evaluation of an artificial intelligence-facilitated sperm detection tool in azoospermic samples for use in ICSI","volume":"49","author":"Goss","year":"2024","journal-title":"Reprod. Biomed. Online"},{"key":"ref_117","doi-asserted-by":"crossref","first-page":"3179","DOI":"10.1007\/s10815-024-03215-5","article-title":"Artificial intelligence interpretation of touch print smear cytology of testicular specimen from patients with azoospermia","volume":"41","author":"Hsu","year":"2024","journal-title":"J. Assist. Reprod. Genet."},{"key":"ref_118","doi-asserted-by":"crossref","first-page":"e240181","DOI":"10.1530\/REP-24-0181","article-title":"Development of a deep-learning model for detecting positive tubules during sperm recovery for nonobstructive azoospermia","volume":"168","author":"Takeshima","year":"2024","journal-title":"Reproduction"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/13\/5965\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T15:54:23Z","timestamp":1783007663000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/13\/5965"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,2]]},"references-count":118,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ijms27135965"],"URL":"https:\/\/doi.org\/10.3390\/ijms27135965","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,2]]}}}