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Examining the neutralizing capacity of monoclonal antibodies (MAbs) used to treat COVID-19, as well as antibodies recovered from unvaccinated, previously vaccinated, and infected individuals, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) remains critical to study. Here, we report on a SARS-CoV-2 nosocomial outbreak caused by the SARS-CoV-2 R.1 variant harboring the E484K mutation in a 281-bed psychiatric facility in New Jersey among unvaccinated inpatients and health care professionals (HCPs). A total of 81 inpatients and HCPs tested positive for SARS-Cov-2 by reverse transcription (RT)-PCR from 29 October 9 to 30 November 2020. The R.1 variant exhibits partial or complete resistance to two MAbs in clinical use, as well as 2 receptor binding domain MAbs and 4 N-terminal domain (NTD) MAbs. NTD MAbs against pseudovirus harboring single characteristic R.1 mutations highlight the role of S255F in loss of activity. Additionally, we note dampened neutralization capacity by plasma from individuals with previous SARS-CoV-2 infection or sera from vaccinated individuals. The relative resistance of the R.1 variant is likely lower than that of B.1.351 and closer to that of P.1 and B.1.526. The R.1 lineage has been reported in 47 states in the United States and 40 countries. Although high proportions exhibited symptoms (26% and 61% among patients and HCPs, respectively) and relative antibody resistance, we detected only 10 R.1 variants from over 2,900 samples (~0.34%) collected from January to October 2021. Among 3 vaccinated individuals previously infected with R.1, we observed robust neutralizing antibody responses against SARS-CoV-2 wild type and VOCs. IMPORTANCE The neutralizing capacities of monoclonal antibodies used to treat COVID-19 and of those recovered from previously infected and vaccinated individuals against SARS-CoV-2 variants of concern (VOCs) remain important questions. We report on a nosocomial outbreak caused by a SARS-CoV-2 R.1 variant harboring an E484K mutation among 81 unvaccinated inpatients and health care professionals. We note high attack rates with symptoms in nearly 50% of infected individuals, in sharp contrast to an unrelated institutional outbreak caused by the R.1 variant among a vaccinated population. We found little evidence of significant community spillover. This variant exhibits partial or complete resistance to two monoclonal antibodies in clinical use and dampened the neutralization capacity of convalescent-phase plasma from individuals with previous infection or sera from vaccinated individuals. Among three vaccinated individuals previously infected with R.1, we observed robust neutralizing antibody responses against SARS-CoV-2 wild type and VOCs. These findings underscore the importance of vaccination for prevention of symptomatic COVID-19 disease.

Differential responses to immune checkpoint inhibitors (ICI) may be attributed to tumor-intrinsic factors or environmental cues; however, these mechanisms cannot fully explain the variable ICI responses in different individuals. Here, we investigate the potential contribution of immunological heterogeneity with a focus on differences in T-cell receptor (TCR) repertoire to ICI responses, which has not been defined previously. To reveal additional factors underlying heterogeneous responses to ICI, we employed a squamous cell carcinoma (SCC) mouse model in which tumor-bearing recipients unambiguously diverged into responders (R) or non-responders (NR) upon anti-PD-L1 treatment. Treatment efficacy absolutely required CD8 T-cells and correlated positively with effector functions of CD8 tumor-infiltrating lymphocytes (TILs). We showed that TCR repertoires exhibited a similar magnitude of clonal expansion in R vs . NR CD8 TILs. However, the top expanded TCR clonotypes appeared to be mutually exclusive between R and NR CD8 TILs, which also occurred in a recipient-specific manner, demonstrating preferential expansion of distinct TCR clonotypes against the same SCC tumor. Unexpectedly, R vs . NR CD8 TILs reached all activation clusters and did not exhibit substantial global differences in transcriptomes. By linking single-cell transcriptomic data with unique TCR clonotypes, CD8 TILs harboring top TCR clonotypes were found to occupy distinct activation clusters and upregulate genes favoring anti-tumor immunity to different extents in R vs . NR. We conclude that stochastic differences in CD8 TIL TCR repertoire and distinct activation states of top TCR clonotypes may contribute to differential anti-PD-L1 responses. Our study suggests that host-intrinsic immunological heterogeneity may offer a new explanation for differential ICI responses in different individuals, which could impact on strategies for personalized cancer immunotherapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 John, Woolaver, Popolizio, Chen, Ge, Krinsky, Vashisht, Kramer, Chen and Wang.)

Background: While immune checkpoint inhibitors (ICI) were approved for head and neck squamous cell carcinomas (HNSCCs), the response rate remains relatively low. Mechanisms underlying ICI unresponsiveness versus sensitivity are not fully understood., Method: To better delineate differential responses to ICI treatment, we employed mouse SCC models, termed KPPA tumors that were caused by deleting p53 and hyperactivating PIK3CA, two most frequently mutated genes in human HNSCCs. We transplanted two KPPA tumor lines (TAb2 versus TCh3) into C57BL/6 recipients and examined the immune tumor microenvironment using flow cytometry. Furthermore, we employed single-cell RNA sequencing to identify the difference in tumor infiltrating lymphocytes (TILs)., Results: We found that different KPPA tumors exhibited heterogeneous immune profiles pre-existing treatment that dictated their sensitivity or unresponsiveness to anti-PD-L1. Unresponsive TAb2 tumors were highly enriched with functional tumor-associated macrophages (TAMs), especially M2-TAMs. In contrast, sensitive TCh3 tumors contained more CD8 TILs with better effector functions. TAb2 tumor cells drastically expanded F4/80 + TAMs from bone marrow precursors, requiring CSF1 and VEGF. Consistently, a higher combined expression of VEGF-C and CSF1 predicts worse survival in PIK3CA Amp /TP53 Mutated HNSCC patients. Unresponsive TAb2 tumors upregulated distinct signaling pathways that correlate with aggressive tumor phenotypes. While anti-PD-L1 did not affect the TME of TAb2 tumors, it significantly increased the number of CD8 TILs in TCh3 tumors., Conclusions: We uncovered tumor-intrinsic differences that may underlie the differential responses to ICI by establishing and employing two SCC tumor lines, TAb2 vs. TCh3, both of which harbor TP53 deletion and PIK3CA hyperactivation. Our study indicates the limitation of stratifying cancers according to their genetic alterations and suggests that evaluating HNSCC tumor-intrinsic cues along with immune profiles in the TME may help better predict ICI responses. Our experimental models may provide a platform for pinpointing tumor-intrinsic differences underlying an immunosuppressive TME in HNSCCs and for testing combined immunotherapies targeting either tumor-specific or TAM-specific players to improve ICI efficacy., (© 2022. The Author(s).)

Emergence of SARS-CoV-2 with high transmission and immune evasion potential, the so-called variants of concern (VOC), is a major concern. We describe the early genomic epidemiology of SARS-CoV-2 recovered from vaccinated health care professionals (HCP). Our postvaccination COVID-19 symptoms-based surveillance program among HCPs in a 17-hospital network identified all vaccinated HCPs who tested positive for COVID-19 after routine screening or after self-reporting. From 1 January 2021 to 30 April 2021, 23,687 HCPs received either mRNA-1273 or BNT162b2 mRNA vaccine. All available postvaccination SARS-CoV-2 samples and a random collection from nonvaccinated patients during the similar time frame were subjected to VOC screening and whole-genome sequencing (WGS). Sixty-two percent (23,697/37,500) of HCPs received at least one vaccine dose, with 60% (22,458) fully vaccinated. We detected 138 (0.58%, 138/23,697) COVID-19 cases, 105 among partially vaccinated and 33 (0.15%, 33/22,458) among fully vaccinated. Five partially vaccinated required hospitalization, four with supplemental oxygen. VOC screening from 16 fully vaccinated HCPs identified 6 (38%) harboring N501Y and 1 (6%) with E484K polymorphisms; percentage of concurrent nonvaccinated samples was 37% (523/1,404) and 20% (284/1,394), respectively. There was an upward trend from January to April for E484K/Q (3% to 26%) and N501Y (1% to 49%). WGS analysis from vaccinated and nonvaccinated individuals indicated highly congruent phylogenies. We did not detect an increased frequency of any receptor-binding domain (RBD)/N-terminal domain (NTD) polymorphism between groups ( P  > 0.05). Our results support robust protection by vaccination, particularly among recipients of both doses. Despite VOCs accounting for over 40% of SARS-CoV-2 from fully vaccinated individuals, the genomic diversity appears to proportionally represent VOCs among nonvaccinated populations. IMPORTANCE A number of highly effective vaccines have been developed and deployed to combat the COVID-19 pandemic. The emergence and epidemiological dominance of SARS-CoV-2 mutants with high transmission potential and immune evasion properties, the so-called variants of concern (VOC), continue to be a major concern. Whether these VOCs alter the efficacy of the administered vaccines is of great concern and a critical question to study. We describe the initial genomic epidemiology of SARS-CoV-2 recovered from partial/fully vaccinated health care professionals and probe specifically for VOC enrichment. Our findings support the high level of protection provided by full vaccination despite a steep increase in the prevalence of polymorphisms associated with increased transmission potential (N501Y) and immune evasion (E484K) in the nonvaccinated population. Thus, we do not find evidence of VOC enrichment among vaccinated groups. Overall, the genomic diversity of SARS-CoV-2 recovered postvaccination appears to proportionally represent the observed viral diversity within the community.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs), harboring spike protein N-terminal domain (NTD) or receptor-binding domain (RBD) mutations, exhibit reduced in vitro susceptibility to convalescent-phase serum, commercial antibody cocktails, and vaccine neutralization and have been associated with reinfections. The accumulation of these mutations could be the consequence of intrahost viral evolution due to prolonged infection in immunocompromised hosts. In this study, we document the microevolution of SARS-CoV-2 recovered from sequential tracheal aspirates from an immunosuppressed patient on steroids and convalescent plasma therapy and identify the emergence of multiple NTD and RBD mutations. SARS-CoV-2 genomes from the first swab (day 0) and from three tracheal aspirates (days 7, 21, and 27) were compared at the sequence level. We identified a mixed viral population with five different S protein mutations (141 to 144 deletion, 243 to 244 deletion, E484K, Q493K, and Q493R) at the NTD or RBD region from the second tracheal aspirate sample (day 21) and a predominance of the S protein 141 to 144 LGVY deletion and E484K mutant on day 27. The neutralizing antibodies against various S protein lentiviral pseudovirus mutants, as well as the anti-SARS-CoV-2 total Ig and IgG, showed "U" shape dynamics, in support of the endogenous development of neutralizing antibodies. The patient's compromised immune status, the antirejection regiment, convalescent plasma treatment, and the development of neutralizing antibodies may have resulted in unique selective pressures on the intrahost genomic evolution, and this observation supports the hypotheses that VOCs can independently arise and that immunocompromised patients on convalescent plasma therapy are potential breeding grounds for immune escape mutants. IMPORTANCE Over a year of the COVID-19 pandemic, distinct severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineages have arisen in multiple geographic areas around the world. SARS-CoV-2 variants of concern (VOCs), i.e., B.1.1.7 (alpha), B.1.351 (beta), P.1 (gamma), and B.1.617.2 (delta), harboring mutations and/or deletions in spike protein N-terminal domain (NTD) or receptor-binding domain (RBD) regions showed evidence of increased transmissibility and disease severity and possible reduced vaccine efficacy. In this study, we report the emergence of five different NTD and RBD mutations in an uncommon SARS-CoV-2 B.1.369 lineage from an immunosuppressed patient undergoing steroid and convalescent plasma therapy. The observation highlighted that VOCs can independently arise in immunocompromised populations undergoing anti-SARS-CoV-2 therapy, and enhanced measures will be required to reduce the transmission.

Circulating nucleic acids, encapsulated within small extracellular vesicles (EVs), provide a remote cellular snapshot of biomarkers derived from diseased tissues, however selective isolation is critical. Current laboratory-based purification techniques rely on the physical properties of small-EVs rather than their inherited cellular fingerprints. We established a highly-selective purification assay, termed EV-CATCHER, initially designed for high-throughput analysis of low-abundance small-RNA cargos by next-generation sequencing. We demonstrated its selectivity by specifically isolating and sequencing small-RNAs from mouse small-EVs spiked into human plasma. Western blotting, nanoparticle tracking, and transmission electron microscopy were used to validate and quantify the capture and release of intact small-EVs. As proof-of-principle for sensitive detection of circulating miRNAs, we compared small-RNA sequencing data from a subset of small-EVs serum-purified with EV-CATCHER to data from whole serum, using samples from a small cohort of recently hospitalized Covid-19 patients. We identified and validated, only in small-EVs, hsa-miR-146a and hsa-miR-126-3p to be significantly downregulated with disease severity. Separately, using convalescent sera from recovered Covid-19 patients with high anti-spike IgG titers, we confirmed the neutralizing properties, against SARS-CoV-2 in vitro, of a subset of small-EVs serum-purified by EV-CATCHER, as initially observed with ultracentrifuged small-EVs. Altogether our data highlight the sensitivity and versatility of EV-CATCHER., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper., (© 2021 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles.)

Purpose: To assess the accuracy and reliability of comprehensive chromosome screening by next-generation sequencing (NGS) of human trophectoderm (TE) biopsy specimens., Methods: The reliability and accuracy of diagnoses made by preimplantation genetic testing for aneuploidy (PGT-A) from TE biopsy were tested. Repeat biopsies of TE and inner cell mass (ICM) samples were obtained from thawed blastocysts previously tested by NGS. To test for the reliability of the NGS assay, biopsy samples were compared with the original PGT-A results. Prior NGS testing classified the TE samples as euploid, aneuploid, or aneuploid-mosaic. The resulting re-biopsied samples underwent SurePlex whole genome amplification followed by NGS via the MiSeq platform, with copy number value (CNV) determined using BlueFuse Multi Software. The primary outcome measure was reliability, defined as concordance between initial TE result and the repeat biopsies. Accuracy was determined by concordance between the TE and ICM samples, and compared between three chromosome types (disomic, aneuploid, and mosaic)., Results: Re-biopsies were performed on 32 embryos with prior PGT-A showing euploidy (10 embryos), aneuploidy of one or two chromosomes (4 embryos), or aneuploid-mosaic with one aneuploid chromosome and one mosaic chromosome (18 embryos). One hundred twenty-nine biopsy samples completed NGS (90 TE and 39 ICM biopsies) and 105 biopsy results were included in the analysis. TE biopsies provide a highly accurate test of the future fetus, with the ICM disomic concordance rate of 97.6%. Clinical concordance rates indicate that TE biopsies provide a reliable test when the result is euploid (99.5%) or aneuploid (97.3%), but less reliable when the result is mosaic (35.2%)., Conclusion: TE biopsies predict euploidy or aneuploidy in the ICM with a high degree of accuracy. PGT-A with NGS of TE biopsies is shown to be highly reliable, with clinically relevant concordance rates for aneuploidy and euploidy over 95%. TE biopsies indicating mosaicism were less reliable (35.2%), presumably because mitotic non-disjunction events are not uniformly distributed throughout the blastocyst. However, classification of TE biopsy of PGT-A with NGS results as either aneuploid or euploid provides a highly reliable test.

Purpose: To identify and characterize amyloid-like substance (ALS) in human and mouse oocytes and preimplantation embryos., Methods: An experimental prospective pilot study. A total of 252 mouse oocytes and preimplantation embryos and 50 immature and in vitro matured human oocytes and parthenogenetic human embryos, from 11 consenting fertility patients, ages 18-45. Fluorescence intensity from immunofluorescent staining and data from confocal microscopy were quantified. Data were compared by one-way analysis of variance, with the least square-MEANS post-test, Pearson correlation coefficients (r), and bivariate analyses (t tests). ALS morphology was verified using transmission electron microscopy., Results: Immunostaining for ALS appears throughout the zona pellucida, as well as in the cytoplasm and nucleus of mouse and human oocytes, polar bodies, and parthenogenetic embryos, and mouse preimplantation embryos. In mouse, 2-cell embryos exhibited the highest level of ALS (69000187.4 ± 6733098.07). Electron microscopy confirmed the presence of ALS. In humans, fresh germinal vesicle stage oocytes exhibited the highest level of ALS (4164.74088 ± 1573.46) followed by metaphase I and II stages (p = 0.008). There was a significant negative association between levels of ALS and patient body mass index, number of days of ovarian stimulation, dose of gonadotropin used, time between retrieval and fixation, and time after the hCG trigger. Significantly higher levels of ALS were found in patients with AMH between 1 and 3 ng/ml compared to < 1 ng/ml., Conclusion: We demonstrate for the first time the presence, distribution, and change in ALS throughout some stages of mouse and human oocyte maturation and embryonic development. We also determine associations between ALS in human oocytes with clinical characteristics.

Study Question: What factors are associated with decision regret and anxiety following preimplantation genetic testing for aneuploidy (PGT-A)?, Summary Answer: The majority of patients viewed PGT-A favourably regardless of their outcome; although patients with negative outcomes expressed greater decision regret and anxiety., What Is Known Already: PGT-A is increasingly utilized in in vitro fertilization (IVF) cycles to aid in embryo selection. Despite the increasing use of PGT-A technology, little is known about patients' experiences and the possible unintended consequences of decision regret and anxiety related to PGT-A outcome., Study Design, Size, Duration: Anonymous surveys were distributed to 395 patients who underwent their first cycle of autologous PGT-A between January 2014 and March 2015., Participants/materials, Setting, Methods: There were 69 respondents who underwent PGT-A at a university-affiliated fertility centre, completed the survey and met inclusion criteria. Respondents completed three validated questionnaires including the Brehaut Decision Regret (DR) Scale, short-form State-Trait Anxiety Inventory (STAI-6) and a health literacy scale. The surveys also assessed demographics, fertility history, IVF and frozen embryo transfer cycle data., Main Results and the Role of Chance: The majority of respondents were Caucasian, >35 years of age and educated beyond an undergraduate degree. The majority utilized PGT-A on their first IVF cycle, most commonly to 'maximize the efficiency of IVF' or reduce per-transfer miscarriage risk. The overall median DR score was low, but 39% of respondents expressed some degree of regret. Multiple regression confirmed a relationship between embryo ploidy and decision regret, with a lower number of euploid embryos associated with a greater degree of regret. Patients who conceived following euploid transfer reported less regret than those who miscarried or failed to conceive (P < 0.005). Decision regret was inversely associated with number of living children but not associated with age, education, race, insurance coverage, religion, marital status or indication for IVF/PGT-A. Anxiety was greater following a negative pregnancy test or miscarriage compared to successful conception (P < 0.0001). Anxiety was negatively associated with age, time since oocyte retrieval and number of living children, and a relationship was observed between anxiety and religious affiliation. Overall, decision regret was low, and 94% of all respondents reported satisfaction with their decision to pursue PGT-A; however, patients with a negative outcome were more likely to express decision regret and anxiety., Limitations, Reason for Caution: This survey was performed at a single centre with a relatively homogenous population, and the findings may not be generalizable. Reasons for caution include the possibility of response bias and unmeasured differences among those who did and did not respond to the survey, as well as the possibility of recall bias given the retrospective nature of the survey. Few studies have examined patient perceptions of PGT-A, and our findings should be interpreted with caution., Wider Implications of the Findings: Overall decision regret was low following PGT-A, and the vast majority deemed the information gained valuable for reproductive planning regardless of outcome. However, more than one-third of the respondents expressed some degree of regret. Respondents with no euploid embryos were more likely to express regret, and those with a negative outcome following euploid embryo transfer expressed both higher regret and anxiety. These data identify unanticipated consequences of PGT-A and suggest opportunities for additional counselling and support surrounding IVF with PGT-A., Study Funding/competing Interest(s): No external funding was obtained for this study. D.H.M. reports personal fees, honorarium, and travel expenses from Ferring Pharmaceuticals, personal fees and travel expenses from Granata Bio, and personal fees from Biogenetics Corporation, The Sperm and Embryo Bank of New York, and ReproART: Georgian American Center for Reproductive Medicine. All conflicts are outside the submitted work., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

Objective: To evaluate whether the use of next generation sequencing (NGS) for preimplantation genetic screening (PGS) in single thawed euploid embryo transfer (STEET) cycles improves pregnancy outcomes compared with array comparative genomic hybridization (aCGH)., Design: Retrospective cohort study., Setting: Single university-based fertility center., Patient(s): A total of 916 STEET cycles from January 2014 to December 2016 were identified. Cases included 548 STEET cycles using NGS for PGS and controls included 368 STEET cycles using aCGH for PGS., Intervention(s): Patients having a STEET after undergoing IVF and PGS with either NGS or aCGH., Main Outcome Measure(s): Primary outcomes were implantation rate, ongoing pregnancy/live birth rate (OP/LBR), biochemical pregnancy rate (PR), and spontaneous abortion (SAB) rate., Result(s): The implantation rate was significantly higher in the NGS group compared with the aCGH group (71.6% vs. 64.6%). The OP/LBR was also significantly higher in the NGS group (62% vs. 54.4%), and there were significantly more biochemical pregnancies in the aCGH group compared with the NGS group (15.1% vs. 8.7%). After adjustment for confounding variables with a multiple logistic regression analysis, OP/LBR remained significantly higher in the NGS group. The SAB rate was not significantly different in the NGS group compared with the aCGH group (12.4% vs. 12.7%)., Conclusion(s): Preimplantation genetic screening using NGS significantly improves pregnancy outcomes versus PGS using aCGH in STEET cycles. Next-generation sequencing has the ability to identify and screen for embryos with reduced viability such as mosaic embryos and those with partial aneuploidies or triploidy. Pregnancy outcomes with NGS may be improved due to the exclusion of these abnormal embryos., (Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Iron homeostasis is tightly regulated by the membrane iron exporter ferroportin and its regulatory peptide hormone hepcidin. The hepcidin/ferroportin axis is considered a promising therapeutic target for the treatment of diseases of iron overload or deficiency. Here, we conducted a chemical screen in zebrafish to identify small molecules that decrease ferroportin protein levels. The chemical screen led to the identification of 3 steroid molecules, epitiostanol, progesterone, and mifepristone, which decrease ferroportin levels by increasing the biosynthesis of hepcidin. These hepcidin-inducing steroids (HISs) did not activate known hepcidin-inducing pathways, including the BMP and JAK/STAT3 pathways. Progesterone receptor membrane component-1 (PGRMC1) was required for HIS-dependent increases in hepcidin biosynthesis, as PGRMC1 depletion in cultured hepatoma cells and zebrafish blocked the ability of HISs to increase hepcidin mRNA levels. Neutralizing antibodies directed against PGRMC1 attenuated the ability of HISs to induce hepcidin gene expression. Inhibiting the kinases of the SRC family, which are downstream of PGRMC1, blocked the ability of HISs to increase hepcidin mRNA levels. Furthermore, HIS treatment increased hepcidin biosynthesis in mice and humans. Together, these data indicate that PGRMC1 regulates hepcidin gene expression through an evolutionarily conserved mechanism. These studies have identified drug candidates and potential therapeutic targets for the treatment of diseases of abnormal iron metabolism.

Purpose: The effect of age on telomere length heterogeneity in men has not been studied previously. Our aims were to determine the relationship between variation in sperm telomere length (STL), men's age, and semen parameters in spermatozoa from men undergoing in vitro fertilization (IVF) treatment., Methods: To perform this prospective cross-sectional pilot study, telomere length was estimated in 200 individual spermatozoa from men undergoing IVF treatment at the NYU Fertility Center. A novel single-cell telomere content assay (SCT-pqPCR) measured telomere length in individual spermatozoa., Results: Telomere length among individual spermatozoa within an ejaculate varies markedly and increases with age. Older men not only have longer STL but also have more variable STL compared to younger men. STL from samples with normal semen parameters was significantly longer than that from samples with abnormal parameters, but STL did not differ between spermatozoa with normal versus abnormal morphology., Conclusion: The marked increase in STL heterogeneity as men age is consistent with a role for ALT during spermatogenesis. No data have yet reported the effect of age on STL heterogeneity. Based on these results, future studies should expand this modest sample size to search for molecular evidence of ALT in human testes during spermatogenesis.

Objective: To determine if long-term cryopreservation of human oocytes affects oocyte developmental competence, blastocyst euploidy, or live-birth rates., Design: Retrospective cohort study., Setting: University-based fertility center., Patient(s): A total of 33 patients with cryopreserved oocytes underwent oocyte thaw, blastocyst culture, trophectoderm biopsy, and 24-chromosome preimplantation genetic screening (PGS) with array comparative genomic hybridization between December 2011 and July 2014; subjects were compared with 2:1 age-matched controls with fresh oocytes whose embryos underwent trophectoderm biopsy and PGS during the same period., Intervention(s): None., Main Outcome Measure(s): Rates of fertilization, blastulation, euploidy, implantation, and live birth., Result(s): Thirty-three patients (mean age 36.2 ± 3.8 y) thawed 475 oocytes that had been cryopreserved for a median of 3.5 years. Compared with 66 age-matched controls who underwent in vitro fertilization and PGS with fresh oocytes, embryos derived from cryopreserved oocytes demonstrated compromised blastocyst formation (54.5% vs. 66.2%) despite no impairment in fertilization (72.8% vs. 73.2%). Results showed no difference in the number of euploid blastocysts (1.7 ± 1.9 vs. 2 ± 2.5), percentage of euploid blastocysts (44.5% vs. 47.6%), rate of implantation (65% vs. 65%), or rate of live birth and ongoing pregnancy (62.5% vs. 55%) after 24-chromosome PGS with cryopreserved or fresh oocytes., Conclusion(s): Embryos derived from cryopreserved oocytes demonstrate impaired blastulation but equivalent rates of euploidy, implantation, and live birth compared with blastocysts derived from fresh oocytes, supporting the safety and efficacy of oocyte cryopreservation., (Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)