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Martín Á, Mercader A, Beltrán D, Mifsud A, Nohales M, Pardiñas ML, Ortega-Jaén D, de Los Santos MJ. Trophectoderm cells of human mosaic embryos display increased apoptotic levels and impaired differentiation capacity: a molecular clue regarding their reproductive fate? Hum Reprod 2024; 39:709-723. [PMID: 38308811 DOI: 10.1093/humrep/deae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/29/2023] [Indexed: 02/05/2024] Open
Abstract
STUDY QUESTION Are there cell lineage-related differences in the apoptotic rates and differentiation capacity of human blastocysts diagnosed as euploid, mosaic, and aneuploid after preimplantation genetic testing for aneuploidy (PGT-A) based on concurrent copy number and genotyping analysis? SUMMARY ANSWER Trophectoderm (TE) cells of mosaic and aneuploid blastocysts exhibit significantly higher levels of apoptosis and significantly reduced differentiation capacity compared to those of euploid blastocysts. WHAT IS KNOWN ALREADY Embryos diagnosed as mosaic after PGT-A can develop into healthy infants, yet understanding the reasons behind their reproductive potential requires further research. One hypothesis suggests that mosaicism can be normalized through selective apoptosis and reduced proliferation of aneuploid cells, but direct evidence of these mechanisms in human embryos is lacking. Additionally, data interpretation from studies involving mosaic embryos has been hampered by retrospective analysis methods and the high incidence of false-positive mosaic diagnoses stemming from the use of poorly specific PGT-A platforms. STUDY DESIGN, SIZE, DURATION Prospective cohort study performing colocalization of cell-lineage and apoptotic markers by immunofluorescence (IF). We included a total of 64 human blastocysts donated to research on Day 5 or 6 post-fertilization (dpf) by 43 couples who underwent in vitro fertilization treatment with PGT-A at IVI-RMA Valencia between September 2019 and October 2022. A total of 27 mosaic blastocysts were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS The study consisted of two phases: Phase I (caspase-3, n = 53 blastocysts): n = 13 euploid, n = 22 mosaic, n = 18 aneuploid. Phase II (terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), n = 11 blastocysts): n = 2 euploid, n = 5 mosaic, n = 4 aneuploid. Following donation for research, vitrified blastocysts were warmed, cultured until re-expansion, fixed, processed for IF, and imaged using confocal microscopy. For each blastocyst, the following cell counts were conducted: total cells (DAPI+), TE cells (GATA3+), inner cell mass (ICM) cells (GATA3-/NANOG+), and apoptotic cells (caspase-3+ or TUNEL+). The incidence of apoptosis was calculated for each blastocyst by dividing the number of caspase-3+ cells (Phase I) or TUNEL+ cells (Phase II) by the number of TE or ICM cells. Statistical analysis was performed according to data type and distribution (P < 0.05 was considered statistically significant). MAIN RESULTS AND THE ROLE OF CHANCE Phase I: Mosaic blastocysts displayed a similar number of total cells (49.6 ± 15 cells at 5 dpf; 58.8 ± 16.9 cells at 6 dpf), TE cells (38.8 ± 13.7 cells at 5 dpf; 49.2 ± 16.2 cells at 6 dpf), and ICM cells (10.9 ± 4.2 cells at 5 dpf; 9.7 ± 7.1 cells at 6 dpf) compared to euploid and aneuploid blastocysts (P > 0.05). The proportion of TE cells retaining NANOG expression increased gradually from euploid blastocysts (9.7% = 63/651 cells at 5 dpf; 0% = 0/157 cells at 6 dpf) to mosaic blastocysts (13.1% = 104/794 cells at 5 dpf; 3.4% = 12/353 cells at 6 dpf) and aneuploid blastocysts (27.9% = 149/534 cells at 5 dpf; 4.6% = 19/417 cells at 6 dpf) (P < 0.05). At the TE level, caspase-3+ cells were frequently observed (39% = 901/2310 cells). The proportion of caspase-3+ TE cells was significantly higher in mosaic blastocysts (44.1% ± 19.6 at 5 dpf; 43% ± 16.8 at 6 dpf) and aneuploid blastocysts (45.9% ± 16.1 at 5 dpf; 49% ± 15.1 at 6 dpf) compared to euploid blastocysts (26.6% ± 16.6 at 5 dpf; 17.5% ± 14.8 at 6 dpf) (P < 0.05). In contrast, at the ICM level, caspase-3+ cells were rarely observed (1.9% = 11/596 cells), and only detected in mosaic blastocysts (2.6% = 6/232 cells) and aneuploid blastocysts (2.5% = 5/197 cells) (P > 0.05). Phase II: Consistently, TUNEL+ cells were only observed in TE cells (32.4% = 124/383 cells). An increasing trend was identified toward a higher proportion of TUNEL+ cells in the TE of mosaic blastocysts (37.2% ± 21.9) and aneuploid blastocysts (39% ± 41.7), compared to euploid blastocysts (23% ± 32.5), although these differences did not reach statistical significance (P > 0.05). LIMITATIONS, REASONS FOR CAUTION The observed effects on apoptosis and differentiation may not be exclusive to aneuploid cells. Additionally, variations in aneuploidies and unexplored factors related to blastocyst development and karyotype concordance may introduce potential biases and uncertainties in the results. WIDER IMPLICATIONS OF THE FINDINGS Our findings demonstrate a cell lineage-specific effect of aneuploidy on the apoptotic levels and differentiation capacity of human blastocysts. This contributes to unravelling the biological characteristics of mosaic blastocysts and supports the concept of clonal depletion of aneuploid cells in explaining their reproductive potential. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by grants from Centro para el Desarrollo Tecnológico Industrial (CDTI) (20190022) and Generalitat Valenciana (APOTIP/2019/009). None of the authors has any conflict of interest to declare. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- Ángel Martín
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
| | - Amparo Mercader
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - Diana Beltrán
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - Amparo Mifsud
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - Mar Nohales
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - María Luisa Pardiñas
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
| | - David Ortega-Jaén
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
| | - María José de Los Santos
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
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Muñoz E, Bronet F, Lledo B, Palacios-Verdú G, Martinez-Rocca L, Altmäe S, Pla J. To transfer or not to transfer: the dilemma of mosaic embryos - a narrative review. Reprod Biomed Online 2024; 48:103664. [PMID: 38408811 DOI: 10.1016/j.rbmo.2023.103664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/19/2023] [Accepted: 10/30/2023] [Indexed: 02/28/2024]
Abstract
A frequent finding after preimplantation genetic diagnostic testing for aneuploidies using next-generation sequencing is an embryo that is putatively mosaic. The prevalence of this outcome remains unclear and varies with technical and external factors. Mosaic embryos can be classified by the percentage of cells affected, type of chromosome involvement (whole or segmental), number of affected chromosomes or affected cell type (inner mass cell, trophectoderm or both). The origin of mosaicism seems to be intrinsic as a post-zygotic mitotic error, but some external factors can play a role. As experience has increased with the transfer of mosaic embryos, clinical practice has gradually become more flexible in recent years. Nevertheless, clinical results show lower implantation, pregnancy and clinical pregnancy rates and higher miscarriage rates with mosaic embryo transfer when compared with the transfer of euploid embryos. Prenatal diagnosis is highly recommended after the transfer of mosaic embryos. This narrative review is intended to serve as reference material for practitioners in reproductive medicine who must manage a mosaic embryo result after preimplantation genetic testing for aneuploidies.
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Affiliation(s)
- Elkin Muñoz
- Reproductive Medicine, IVIRMA Vigo, Vigo, Spain; Department of Obstetrics and Gynecology, University of Cauca, Popayan, Colombia
| | | | | | - Gabriela Palacios-Verdú
- Unit of Genomic Medicine, Department of Obstetrics, Gynecology and Reproductive Medicine, Institut Universitari Quirón Dexeus, Barcelona, Spain
| | | | - Signe Altmäe
- Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria ibs, Granada, Granada, Spain; Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Josep Pla
- Reproductive Genetics Unit, IVIRMA Global, Barcelona, Spain.
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Greco E, Greco PF, Listorti I, Ronsini C, Cucinelli F, Biricik A, Viotti M, Meschino N, Spinella F. The mosaic embryo: what it means for the doctor and the patient. Minerva Obstet Gynecol 2024; 76:89-101. [PMID: 37427860 DOI: 10.23736/s2724-606x.23.05281-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
INTRODUCTION Mosaic embryos are embryos that on preimplantation genetic analysis are found to be composed of euploid and aneuploid cells. Although most of these embryos do not implant when transferred into the uterus following IVF treatment, some may implant and are capable of giving rise to babies. EVIDENCE ACQUISITION There is currently an increasing number of reports of live births following the transfer of mosaic embryos. Compared to euploid, mosaic embryos have lower implantation rates and higher rates of miscarriage, and occasionally aneuploid component persists. However, their outcome is better than that obtained after the transfer of embryos consisting entirely of aneuploid cells. After implantation, the ability to develop into a full-term pregnancy is influenced by the amount and type of chromosomal mosaicism present in a mosaic embryo. Nowadays many experts in the reproductive field consider mosaic transfers as an option when no euploid embryos are available. Genetic counseling is an important part of educating patients about the likelihood of having a pregnancy with healthy baby but also on the risk that mosaicism could persist and result in liveborn with chromosomal abnormality. Each situation needs to be assessed on a case-by-case basis and counseled accordingly. EVIDENCE SYNTHESIS So far, the transfers of 2155 mosaic embryos have been documented and 440 live births resulting in healthy babies have been reported. In addition, in the literature to date, there are 6 cases in which embryonic mosaicism persisted. CONCLUSIONS In conclusion, the available data indicate that mosaic embryos have the potential to implant and develop into healthy babies, albeit with lower success rates than euploids. Further clinical outcomes should be collected to better establish a refined ranking of embryos to transfer.
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Affiliation(s)
- Ermanno Greco
- Department of Obstetrics and Gynecology, UniCamillus International University, Rome, Italy
- Villa Mafalda, Centre For Reproductive Medicine, Rome, Italy
| | - Pier F Greco
- Villa Mafalda, Centre For Reproductive Medicine, Rome, Italy
| | - Ilaria Listorti
- Villa Mafalda, Centre For Reproductive Medicine, Rome, Italy
| | - Carlo Ronsini
- Department of Women and Children, Luigi Vanvitelli University of Campania, Naples, Italy
- Department of General and Specialist Surgery, Luigi Vanvitelli University of Campania, Naples, Italy
| | - Francesco Cucinelli
- Reproductive Unit, Department of Obstetrics and Gynaecology, San Camillo Forlanini Hospital, Rome, Italy
| | | | - Manuel Viotti
- Kindlabs, Kindbody, New York, NY, USA
- Zouves Foundation for Reproductive Medicine, Foster City, CA, USA
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Lee CI, Huang CC, Lee TH, Chen HH, Cheng EH, Lin PY, Yu TN, Chen CI, Chen CH, Lee MS. Associations between the artificial intelligence scoring system and live birth outcomes in preimplantation genetic testing for aneuploidy cycles. Reprod Biol Endocrinol 2024; 22:12. [PMID: 38233926 PMCID: PMC10792866 DOI: 10.1186/s12958-024-01185-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 01/12/2024] [Indexed: 01/19/2024] Open
Abstract
BACKGROUND Several studies have demonstrated that iDAScore is more accurate in predicting pregnancy outcomes in cycles without preimplantation genetic testing for aneuploidy (PGT-A) compared to KIDScore and the Gardner criteria. However, the effectiveness of iDAScore in cycles with PGT-A has not been thoroughly investigated. Therefore, this study aims to assess the association between artificial intelligence (AI)-based iDAScore (version 1.0) and pregnancy outcomes in single-embryo transfer (SET) cycles with PGT-A. METHODS This retrospective study was approved by the Institutional Review Board of Chung Sun Medical University, Taichung, Taiwan. Patients undergoing SET cycles (n = 482) following PGT-A at a single reproductive center between January 2017 and June 2021. The blastocyst morphology and morphokinetics of all embryos were evaluated using a time-lapse system. The blastocysts were ranked based on the scores generated by iDAScore, which were defined as AI scores, or by KIDScore D5 (version 3.2) following the manufacturer's protocols. A single blastocyst without aneuploidy was transferred after examining the embryonic ploidy status using a next-generation sequencing-based PGT-A platform. Logistic regression analysis with generalized estimating equations was conducted to assess whether AI scores are associated with the probability of live birth (LB) while considering confounding factors. RESULTS Logistic regression analysis revealed that AI score was significantly associated with LB probability (adjusted odds ratio [OR] = 2.037, 95% confidence interval [CI]: 1.632-2.542) when pulsatility index (PI) level and types of chromosomal abnormalities were controlled. Blastocysts were divided into quartiles in accordance with their AI score (group 1: 3.0-7.8; group 2: 7.9-8.6; group 3: 8.7-8.9; and group 4: 9.0-9.5). Group 1 had a lower LB rate (34.6% vs. 59.8-72.3%) and a higher rate of pregnancy loss (26% vs. 4.7-8.9%) compared with the other groups (p < 0.05). The receiver operating characteristic curve analysis verified that the iDAScore had a significant but limited ability to predict LB (area under the curve [AUC] = 0.64); this ability was significantly weaker than that of the combination of iDAScore, type of chromosomal abnormalities, and PI level (AUC = 0.67). In the comparison of the LB groups with the non-LB groups, the AI scores were significantly lower in the non-LB groups, both for euploid (median: 8.6 vs. 8.8) and mosaic (median: 8.0 vs. 8.6) SETs. CONCLUSIONS Although its predictive ability can be further enhanced, the AI score was significantly associated with LB probability in SET cycles. Euploid or mosaic blastocysts with low AI scores (≤ 7.8) were associated with a lower LB rate, indicating the potential of this annotation-free AI system as a decision-support tool for deselecting embryos with poor pregnancy outcomes following PGT-A.
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Affiliation(s)
- Chun-I Lee
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
- Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Chun-Chia Huang
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Tsung-Hsien Lee
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
- Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Hsiu-Hui Chen
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan
| | - En-Hui Cheng
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Pin-Yao Lin
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Tzu-Ning Yu
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
| | - Chung-I Chen
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan
| | - Chien-Hong Chen
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan.
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan.
| | - Maw-Sheng Lee
- Division of Infertility, Lee Women's Hospital, Taichung, Taiwan.
- Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan.
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
- Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan.
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Popovic M, Borot L, Lorenzon AR, Lopes ALRDC, Sakkas D, Lledó B, Morales R, Ortiz JA, Polyzos NP, Parriego M, Azpiroz F, Galain M, Pujol A, Menten B, Dhaenens L, Vanden Meerschaut F, Stoop D, Rodriguez M, de la Blanca EP, Rodríguez A, Vassena R. Implicit bias in diagnosing mosaicism amongst preimplantation genetic testing providers: results from a multicenter study of 36 395 blastocysts. Hum Reprod 2024; 39:258-274. [PMID: 37873575 DOI: 10.1093/humrep/dead213] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/15/2023] [Indexed: 10/25/2023] Open
Abstract
STUDY QUESTION Does the diagnosis of mosaicism affect ploidy rates across different providers offering preimplantation genetic testing for aneuploidies (PGT-A)? SUMMARY ANSWER Our analysis of 36 395 blastocyst biopsies across eight genetic testing laboratories revealed that euploidy rates were significantly higher in providers reporting low rates of mosaicism. WHAT IS KNOWN ALREADY Diagnoses consistent with chromosomal mosaicism have emerged as a third category of possible embryo ploidy outcomes following PGT-A. However, in the era of mosaicism, embryo selection has become increasingly complex. Biological, technical, analytical, and clinical complexities in interpreting such results have led to substantial variability in mosaicism rates across PGT-A providers and clinics. Critically, it remains unknown whether these differences impact the number of euploid embryos available for transfer. Ultimately, this may significantly affect clinical outcomes, with important implications for PGT-A patients. STUDY DESIGN, SIZE, DURATION In this international, multicenter cohort study, we reviewed 36 395 consecutive PGT-A results, obtained from 10 035 patients across 11 867 treatment cycles, conducted between October 2015 and October 2021. A total of 17 IVF centers, across eight PGT-A providers, five countries and three continents participated in the study. All blastocysts were tested using trophectoderm biopsy and next-generation sequencing. Both autologous and donation cycles were assessed. Cycles using preimplantation genetic testing for structural rearrangements were excluded from the analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS The PGT-A providers were randomly categorized (A to H). Providers B, C, D, E, F, G, and H all reported mosaicism, whereas Provider A reported embryos as either euploid or aneuploid. Ploidy rates were analyzed using multilevel mixed linear regression. Analyses were adjusted for maternal age, paternal age, oocyte source, number of embryos biopsied, day of biopsy, and PGT-A provider, as appropriate. We compared associations between genetic testing providers and PGT-A outcomes, including the number of chromosomally normal (euploid) embryos determined to be suitable for transfer. MAIN RESULTS AND THE ROLE OF CHANCE The mean maternal age (±SD) across all providers was 36.2 (±5.2). Our findings reveal a strong association between PGT-A provider and the diagnosis of euploidy and mosaicism. Amongst the seven providers that reported mosaicism, the rates varied from 3.1% to 25.0%. After adjusting for confounders, we observed a significant difference in the likelihood of diagnosing mosaicism across providers (P < 0.001), ranging from 6.5% (95% CI: 5.2-7.4%) for Provider B to 35.6% (95% CI: 32.6-38.7%) for Provider E. Notably, adjusted euploidy rates were highest for providers that reported the lowest rates of mosaicism (Provider B: euploidy, 55.7% (95% CI: 54.1-57.4%), mosaicism, 6.5% (95% CI: 5.2-7.4%); Provider H: euploidy, 44.5% (95% CI: 43.6-45.4%), mosaicism, 9.9% (95% CI: 9.2-10.6%)); and Provider D: euploidy, 43.8% (95% CI: 39.2-48.4%), mosaicism, 11.0% (95% CI: 7.5-14.5%)). Moreover, the overall chance of having at least one euploid blastocyst available for transfer was significantly higher when mosaicism was not reported, when we compared Provider A to all other providers (OR = 1.30, 95% CI: 1.13-1.50). Differences in diagnosing and interpreting mosaic results across PGT-A laboratories raise further concerns regarding the accuracy and relevance of mosaicism predictions. While we confirmed equivalent clinical outcomes following the transfer of mosaic and euploid blastocysts, we found that a significant proportion of mosaic embryos are not used for IVF treatment. LIMITATIONS, REASONS FOR CAUTION Due to the retrospective nature of the study, associations can be ascertained, however, causality cannot be established. Certain parameters such as blastocyst grade were not available in the dataset. Furthermore, certain platform-related and clinic-specific factors may not be readily quantifiable or explicitly captured in our dataset. As such, a full elucidation of all potential confounders accounting for variability may not be possible. WIDER IMPLICATIONS OF THE FINDINGS Our findings highlight the strong need for standardization and quality assurance in the industry. The decision not to transfer mosaic embryos may ultimately reduce the chance of success of a PGT-A cycle by limiting the pool of available embryos. Until we can be certain that mosaic diagnoses accurately reflect biological variability, reporting mosaicism warrants utmost caution. A prudent approach is imperative, as it may determine the difference between success or failure for some patients. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Torres Quevedo Grant, awarded to M.P. (PTQ2019-010494) by the Spanish State Research Agency, Ministry of Science and Innovation, Spain. M.P., L.B., A.R.L., A.L.R.d.C.L., N.P.P., M.P., D.S., F.A., A.P., B.M., L.D., F.V.M., D.S., M.R., E.P.d.l.B., A.R., and R.V. have no competing interests to declare. B.L., R.M., and J.A.O. are full time employees of IB Biotech, the genetics company of the Instituto Bernabeu group, which performs preimplantation genetic testing. M.G. is a full time employee of Novagen, the genetics company of Cegyr, which performs preimplantation genetic testing. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- Mina Popovic
- Research and Development, Eugin Group, Barcelona, Spain
| | - Lorena Borot
- Research and Development, Eugin Group, Barcelona, Spain
| | | | | | | | | | | | | | - Nikolaos P Polyzos
- Clínica Dexeus Mujer, Dexeus University Hospital, Barcelona, Spain
- Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Mónica Parriego
- Clínica Dexeus Mujer, Dexeus University Hospital, Barcelona, Spain
| | - Felicitas Azpiroz
- Research and Development, Eugin Group, Barcelona, Spain
- Cegyr-Medicina y Genética Reproductiva-Eugin Group, Buenos Aires, Argentina
| | - Micaela Galain
- Cegyr-Medicina y Genética Reproductiva-Eugin Group, Buenos Aires, Argentina
| | - Aïda Pujol
- Center for Infertility and Human Reproduction, CIRH-Eugin Group, Barcelona, Spain
| | - Björn Menten
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Lien Dhaenens
- Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | | | - Dominic Stoop
- Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | | | | | | | - Rita Vassena
- Research and Development, Eugin Group, Barcelona, Spain
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Campos G, Sciorio R, Fleming S. Healthy Live Births after the Transfer of Mosaic Embryos: Self-Correction or PGT-A Overestimation? Genes (Basel) 2023; 15:18. [PMID: 38275600 PMCID: PMC10815078 DOI: 10.3390/genes15010018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024] Open
Abstract
The implementation of next generation sequencing (NGS) in preimplantation genetic testing for aneuploidy (PGT-A) has led to a higher prevalence of mosaic diagnosis within the trophectoderm (TE) sample. Regardless, mosaicism could potentially increase the rate of live-born children with chromosomic syndromes, though available data from the transfer of embryos with putative PGT-A mosaicism are scarce but reassuring. Even with lower implantation and higher miscarriage rates, mosaic embryos can develop into healthy live births. Therefore, this urges an explanation for the disappearance of aneuploid cells throughout development, to provide guidance in the management of mosaicism in clinical practice. Technical overestimation of mosaicism, together with some sort of "self-correction" mechanisms during the early post-implantation stages, emerged as potential explanations. Unlike the animal model, in which the elimination of genetically abnormal cells from the future fetal lineage has been demonstrated, in human embryos this capability remains unverified even though the germ layer displays an aneuploidy-induced cell death lineage preference with higher rates of apoptosis in the inner cell mass (ICM) than in the TE cells. Moreover, the reported differential dynamics of cell proliferation and apoptosis between euploid, mosaic, and aneuploid embryos, together with pro-apoptosis gene products (cfDNA and mRNA) and extracellular vesicles identified in the blastocoel fluid, may support the hypothesis of apoptosis as a mechanism to purge the preimplantation embryo of aneuploid cells. Alternative hypotheses, like correction of aneuploidy by extrusion of a trisomy chromosome or by monosomic chromosome duplication, are even, though they represent an extremely rare phenomenon. On the other hand, the technical limitations of PGT-A analysis may lead to inaccuracy in embryo diagnoses, identifying as "mosaic" those embryos that are uniformly euploid or aneuploid. NGS assumption of "intermediate copy number profiles" as evidence of a mixture of euploid and aneuploid cells in a single biopsy has been reported to be poorly predictive in cases of mosaicism diagnosis. Additionally, the concordance found between the TE and the ICM in cases of TE biopsies displaying mosaicism is lower than expected, and it correlates differently depending on the type (whole chromosome versus segmental) and the level of mosaicism reported. Thus, in cases of low-/medium-level mosaicism (<50%), aneuploid cells would rarely involve the ICM and other regions. However, in high-level mosaics (≥50%), abnormal cells in the ICM should display higher prevalence, revealing more uniform aneuploidy in most embryos, representing a technical variation in the uniform aneuploidy range, and therefore might impair the live birth rate.
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Affiliation(s)
- Gerard Campos
- Geisinger Medical Center, Women’s Health Fertility Clinic, Danville, PA 17821, USA;
- GIREXX Fertility Clinics, C. de Cartagena, 258, 08025 Girona, Spain
| | - Romualdo Sciorio
- Fertility Medicine and Gynaecological Endocrinology Unit, Department Woman-Mother-Child, Lausanne University Hospital, 1011 Lausanne, Switzerland
| | - Steven Fleming
- Discipline of Anatomy & Histology, School of Medical Sciences, University of Sydney, Sydney, NSW 2006, Australia;
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Kutteh WH, Papas RS, Maisenbacher MK, Dahdouh EM. Role of genetic analysis of products of conception and PGT in managing early pregnancy loss. Reprod Biomed Online 2023; 49:103738. [PMID: 38701633 DOI: 10.1016/j.rbmo.2023.103738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/11/2023] [Accepted: 11/15/2023] [Indexed: 05/05/2024]
Abstract
This article considers the addition of comprehensive 24-chromosomal microarray (CMA) analysis of products of conception (POC) to a standard evaluation for recurrent pregnancy loss (RPL) to help direct treatment towards expectant management versus IVF with preimplantation genetic testing for aneuploidies (PGT-A). The review included retrospective data from 65,333 miscarriages, a prospective evaluation of 378 couples with RPL who had CMA testing of POC and the standard workup, and data from an additional 1020 couples who were evaluated for RPL but did not undergo CMA testing of POC. Aneuploidy in POC explained the pregnancy loss in 57.7% (218/378) of cases. In contrast, the full RPL evaluation recommended by the American Society for Reproductive Medicine identified a potential cause in only 42.9% (600/1398). Combining the data from the RPL evaluation and the results of genetic testing of POC provides a probable explanation for the loss in over 90% (347/378) of women. Couples with an unexplained loss after the standard evaluation with POC aneuploidy accounted for 41% of cases; PGT-A may be considered after expectant management. Conversely, PGT-A would have a limited role in those with a euploid loss and a possible explanation after the standard workup. Categorizing a pregnancy loss as an explained versus unexplained loss after the standard evaluation combined with the results of CMA testing of POC may help identify patients who would benefit from expectant management versus PGT-A.
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Affiliation(s)
- William H Kutteh
- Natera, Inc., San Carlos, CA, USA.; Department of Obstetrics and Gynecology, University of Tennessee Health Sciences Center, Memphis, TN, USA..
| | - Ralph S Papas
- Department of Obstetrics and Gynecology, University of Balamand, Beirut, Lebanon
| | | | - Elias M Dahdouh
- ART Center, CHU Sainte-Justine, Department of Obstetrics and Gynecology, Université de Montréal, Montreal, Canada
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8
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Listorti I, Manzo R, Arrivi C, Mencacci C, Biricik A, Greco E, Greco P. PGT-M, a Useful Tool to Manage the Lynch Syndrome Transmission. Int J Mol Sci 2023; 24:16114. [PMID: 38003305 PMCID: PMC10671219 DOI: 10.3390/ijms242216114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Lynch syndrome is one of the most common hereditary cancer sensitivity syndromes and is caused by autosomal-dominant germline mutations in DNA mismatch repair genes. In patients affected by this syndrome, pre-implantation genetic testing for monogenic disorders (PGT-M) could be the elective technique used to prevent the transmission of this hereditary syndrome to offspring. Notably, despite the severity of the condition, some authors have observed a markedly lower demand for PGT-M in these patients compared to those with other hereditary conditions. A 34-year-old woman with a medical history of Lynch syndrome associated with endometrial cancer came to the Villa Mafalda fertility center in Rome in order to conceive a healthy baby. In a pre-implantation genetic testing for aneuploidy (PGT-A) + PGT-M cycle, eight blastocysts were formed. Six out of eight blastocysts were affected by the same mother syndrome. One of the other two was aneuploid and the other one was a mosaic embryo, which resulted in a healthy pregnancy. The aim of this report is to emphasize the importance of a multidisciplinary approach to managing patients with this condition. In vitro fertilization (IVF), specifically PGT-M, is a tool that allow patients to conceive biological children with lower risk of inheriting the disease.
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Affiliation(s)
- Ilaria Listorti
- Center for Reproductive Medicine, Villa Mafalda, 00199 Rome, Italy (C.M.)
- Faculty of Biosciences and Agro-Food and Environmental Technologies, University of Teramo, 64100 Teramo, Italy
| | - Roberta Manzo
- Center for Reproductive Medicine, Villa Mafalda, 00199 Rome, Italy (C.M.)
| | - Cristiana Arrivi
- Center for Reproductive Medicine, Villa Mafalda, 00199 Rome, Italy (C.M.)
| | - Cecilia Mencacci
- Center for Reproductive Medicine, Villa Mafalda, 00199 Rome, Italy (C.M.)
| | - Anil Biricik
- Eurofins GENOMA Group, Molecular Genetics Laboratories, 00138 Rome, Italy;
| | - Ermanno Greco
- Center for Reproductive Medicine, Villa Mafalda, 00199 Rome, Italy (C.M.)
- Faculty of Biosciences and Agro-Food and Environmental Technologies, University of Teramo, 64100 Teramo, Italy
- Eurofins GENOMA Group, Molecular Genetics Laboratories, 00138 Rome, Italy;
- Department of Obstetrician and Genecology, Saint Camillus International University of Health and Medical Sciences (Unicamillus), 00131 Rome, Italy
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9
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Viotti M, Greco E, Grifo JA, Madjunkov M, Librach C, Cetinkaya M, Kahraman S, Yakovlev P, Kornilov N, Corti L, Biricik A, Cheng EH, Su CY, Lee MS, Bonifacio MD, Cooper AR, Griffin DK, Tran DY, Kaur P, Barnes FL, Zouves CG, Victor AR, Besser AG, Madjunkova S, Spinella F. Chromosomal, gestational, and neonatal outcomes of embryos classified as a mosaic by preimplantation genetic testing for aneuploidy. Fertil Steril 2023; 120:957-966. [PMID: 37532168 DOI: 10.1016/j.fertnstert.2023.07.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 07/25/2023] [Accepted: 07/25/2023] [Indexed: 08/04/2023]
Abstract
OBJECTIVE To understand the clinical risks associated with the transfer of embryos classified as a mosaic using preimplantation genetic testing for aneuploidy. DESIGN Analysis of data collected between 2017 and 2023. SETTING Multicenter. PATIENTS Patients of infertility treatment. INTERVENTION Comparison of pregnancies resulting from embryos classified as euploid or mosaic using the 20%-80% interval in chromosomal intermediate copy numbers to define a mosaic result. MAIN OUTCOME MEASURES Rates of spontaneous abortion, birth weight, length of gestation, incidence of birth defects, and chromosomal status during gestation. RESULTS Implanted euploid embryos had a significantly lower risk of spontaneous abortion compared with mosaic embryos (8.9% [n = 8,672; 95% confidence interval {CI95} 8.3, 9.5] vs. 22.2% [n = 914; CI95 19.6, 25.0]). Embryos with mosaicism affecting whole chromosomes (not segmental) had the highest risk of spontaneous abortion (27.6% [n = 395; CI95 23.2, 32.3]). Infants born from euploid, mosaic, and whole chromosome mosaic embryos had average birth weights and lengths of gestation that were not statistically different (3,118 g and 267 days [n = 488; CI95 3,067, 3,169, and 266, 268], 3052 g and 265 days [n = 488; CI95 2,993, 3,112, and 264,267], 3,159 g and 268 days [n = 194; CI95 3,070, 3,249, and 266,270], respectively). Out of 488 infants from mosaic embryo transfers (ETs), one had overt gross abnormalities as defined by the Centers for Disease Control and Prevention. Most prenatal tests performed on pregnancies from mosaic ETs had normal results, and only three pregnancies produced prenatal test results reflecting the mosaicism detected at the embryonic stage (3 out of 250, 1.2%; CI95 0.25, 3.5). CONCLUSION Although embryos classified as mosaic experience higher rates of miscarriage than euploid embryos (with a particularly high frequency shortly after implantation), infants born of mosaic ETs are similar to infants of euploid ETs. Prenatal testing indicates that mosaicism resolves during most pregnancies, although this process is not perfectly efficient. In a small percentage of cases, the mosaicism persists through gestation. These findings can serve as risk-benefit considerations for mosaic ETs in the fertility clinic.
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Affiliation(s)
- Manuel Viotti
- Zouves Foundation for Reproductive Medicine, Foster City, California; Kindlabs, Kindbody, New York, New York.
| | - Ermanno Greco
- Villa Mafalda, Center For Reproductive Medicine, Rome, Italy
| | - James A Grifo
- New York University Langone Fertility Center, New York, New York
| | - Mitko Madjunkov
- CReATe Fertility Centre, Toronto, Canada; Department of Obstetrics and Gynecology, University of Toronto, Toronto, Canada
| | - Clifford Librach
- CReATe Fertility Centre, Toronto, Canada; Department of Obstetrics and Gynecology, University of Toronto, Toronto, Canada; Institute of Medical Sciences and Department of Physiology, University of Toronto, Toronto, Canada
| | | | | | - Pavel Yakovlev
- Centre for Reproductive Medicine, Co.Ltd. "Next Generation Clinic," Moscow, Russia
| | - Nikolay Kornilov
- Centre for Reproductive Medicine, Co.Ltd. "Next Generation Clinic," Moscow, Russia; Centre for Reproductive Medicine, Co.Ltd. "Next Generation Clinic," St. Petersburg, Russia
| | - Laura Corti
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Anil Biricik
- Eurofins Genoma Group, Molecular Genetics Laboratories, Rome, Italy
| | | | | | - Maw-Sheng Lee
- Lee Women's Hospital, Taichung, Taiwan; Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | | | | | - Darren K Griffin
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Diane Y Tran
- Zouves Fertility Center, Foster City, California
| | - Purvi Kaur
- Zouves Fertility Center, Foster City, California
| | - Frank L Barnes
- Zouves Foundation for Reproductive Medicine, Foster City, California; Zouves Fertility Center, Foster City, California
| | - Christo G Zouves
- Zouves Foundation for Reproductive Medicine, Foster City, California; Zouves Fertility Center, Foster City, California
| | - Andrea R Victor
- School of Biosciences, University of Kent, Canterbury, United Kingdom; Zouves Fertility Center, Foster City, California; Reproductive Medicine Associates of Long Island, Melville, New York
| | - Andria G Besser
- New York University Langone Fertility Center, New York, New York
| | - Svetlana Madjunkova
- CReATe Fertility Centre, Toronto, Canada; Department of Obstetrics and Gynecology, University of Toronto, Toronto, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
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10
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McCoy RC, Summers MC, McCollin A, Ottolini CS, Ahuja K, Handyside AH. Meiotic and mitotic aneuploidies drive arrest of in vitro fertilized human preimplantation embryos. Genome Med 2023; 15:77. [PMID: 37779206 PMCID: PMC10544495 DOI: 10.1186/s13073-023-01231-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 09/12/2023] [Indexed: 10/03/2023] Open
Abstract
BACKGROUND The high incidence of aneuploidy in early human development, arising either from errors in meiosis or postzygotic mitosis, is the primary cause of pregnancy loss, miscarriage, and stillbirth following natural conception as well as in vitro fertilization (IVF). Preimplantation genetic testing for aneuploidy (PGT-A) has confirmed the prevalence of meiotic and mitotic aneuploidies among blastocyst-stage IVF embryos that are candidates for transfer. However, only about half of normally fertilized embryos develop to the blastocyst stage in vitro, while the others arrest at cleavage to late morula or early blastocyst stages. METHODS To achieve a more complete view of the impacts of aneuploidy, we applied low-coverage sequencing-based PGT-A to a large series (n = 909) of arrested embryos and trophectoderm biopsies. We then correlated observed aneuploidies with abnormalities of the first two cleavage divisions using time-lapse imaging (n = 843). RESULTS The combined incidence of meiotic and mitotic aneuploidies was strongly associated with blastocyst morphological grading, with the proportion ranging from 20 to 90% for the highest to lowest grades, respectively. In contrast, the incidence of aneuploidy among arrested embryos was exceptionally high (94%), dominated by mitotic aneuploidies affecting multiple chromosomes. In turn, these mitotic aneuploidies were strongly associated with abnormal cleavage divisions, such that 51% of abnormally dividing embryos possessed mitotic aneuploidies compared to only 23% of normally dividing embryos. CONCLUSIONS We conclude that the combination of meiotic and mitotic aneuploidies drives arrest of human embryos in vitro, as development increasingly relies on embryonic gene expression at the blastocyst stage.
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Affiliation(s)
- Rajiv C McCoy
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21212, USA.
| | - Michael C Summers
- London Women's Clinic, 113-115 Harley Street, Marylebone, London, W1G 6AP, UK
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, Kent, UK
- Present Address: London Women's Clinic, The Chesterfield, Nuffield Health Clinic, 3 Clifton Hill, Bristol, BS8 1BN, UK
| | - Abeo McCollin
- London Women's Clinic, 113-115 Harley Street, Marylebone, London, W1G 6AP, UK
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, Kent, UK
| | - Christian S Ottolini
- London Women's Clinic, 113-115 Harley Street, Marylebone, London, W1G 6AP, UK
- Department of Maternal and Fetal Medicine, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
- Present Address: Juno Genetics Italia, Via Di Quarto Peperino 22, 00188, Rome, Italy
| | - Kamal Ahuja
- London Women's Clinic, 113-115 Harley Street, Marylebone, London, W1G 6AP, UK
| | - Alan H Handyside
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, Kent, UK
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11
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Martin A, Mercader A, Dominguez F, Quiñonero A, Perez M, Gonzalez-Martin R, Delgado A, Mifsud A, Pellicer A, De Los Santos MJ. Mosaic results after preimplantation genetic testing for aneuploidy may be accompanied by changes in global gene expression. Front Mol Biosci 2023; 10:1180689. [PMID: 37122560 PMCID: PMC10140421 DOI: 10.3389/fmolb.2023.1180689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/04/2023] [Indexed: 05/02/2023] Open
Abstract
Aneuploidy in preimplantation embryos is a major cause of human reproductive failure. Unlike uniformly aneuploid embryos, embryos diagnosed as diploid-aneuploid mosaics after preimplantation genetic testing for aneuploidy (PGT-A) can develop into healthy infants. However, the reason why these embryos achieve full reproductive competence needs further research. Current RNA sequencing techniques allow for the investigation of the human preimplantation transcriptome, providing new insights into the molecular mechanisms of embryo development. In this prospective study, using euploid embryo gene expression as a control, we compared the transcriptome profiles of inner cell mass and trophectoderm samples from blastocysts with different levels of chromosomal mosaicism. A total of 25 samples were analyzed from 14 blastocysts with previous PGT-A diagnosis, including five low-level mosaic embryos and four high-level mosaic embryos. Global gene expression profiles visualized in cluster heatmaps were correlated with the original PGT-A diagnosis. In addition, gene expression distance based on the number of differentially expressed genes increased with the mosaic level, compared to euploid controls. Pathways involving apoptosis, mitosis, protein degradation, metabolism, and mitochondrial energy production were among the most deregulated within mosaic embryos. Retrospective analysis of the duration of blastomere cell cycles in mosaic embryos revealed several mitotic delays compared to euploid controls, providing additional evidence of the mosaic status. Overall, these findings suggest that embryos with mosaic results are not simply a misdiagnosis by-product, but may also have a genuine molecular identity that is compatible with their reproductive potential.
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Affiliation(s)
- A. Martin
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
| | - A. Mercader
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
- IVI-RMA Valencia, Valencia, Spain
| | - F. Dominguez
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
| | - A. Quiñonero
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
| | - M. Perez
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
| | | | | | | | - A. Pellicer
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
- IVI-RMA Rome, Rome, Italy
| | - M. J. De Los Santos
- IVI-RMA Foundation, Health Research Institute La Fe, Valencia, Spain
- IVI-RMA Valencia, Valencia, Spain
- *Correspondence: M. J. De Los Santos,
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