Chromosomal segregation analysis and HOST-based sperm selection in a complex reciprocal translocation carrier.

INTRODUCTION: Complex chromosomal rearrangements (CCRs) involve two or more chromosomes and at least three breakpoints. Due to their complexity, they are associated with a high number of unbalanced gametes, whose fertilization is often incompatible with viable fetal development. Preimplantation genetic diagnosis (PGD) is usually offered to those patients and typically shows modest results considering the high number of unbalanced embryos. We previously showed that a sperm selection process using the hypo-osmotic swelling test (HOST) allows for an 83% reduction in the proportion of unbalanced spermatozoa (US) in male rearrangements carriers. This is the first report of the use of this procedure in a CCR carrier. CASE DESCRIPTION: We report on the case of a 36-year-old male t(4;7;14)(q12;p21;q11.2) carrier who presented to our center for infertility. Sperm fluorescent in situ hybridization showed an 88% proportion of unbalanced spermatozoa. After hypo-osmotic incubation and selection of spermatozoa with a specific flagellar conformation, the proportion of unbalanced spermatozoa dropped to 15%. DISCUSSION: In the present case, we show that it is possible to select chromosomally balanced prior to in vitro fertilization in male CCR carriers. This technique has the potential of increasing the proportion of euploid embryos and therefore the chances of healthy pregnancy and birth.

The Next Frontier in ART: Harnessing the Uterine Immune Profile for Improved Performance.

Assisted reproduction techniques have improved considerably in recent decades, but despite these advances, success rates remain relatively low. Endometrial immune profiling involves the analysis of cytokine biomarkers in the endometrium during the mid-luteal phase. This profiling aims to provide insights into the immune environment of the uterus. The aim is to identify immune disturbances and thus guide the development of personalized therapeutic approaches. The first part of the review looks back at the emergence of innovative concepts, highlighting the specificity of the human uterine environment at the time of implantation. Based on this new knowledge, biomarkers have been selected for endometrial immune profiling. The second part details the results of clinical studies conducted over the last ten years. These clinical results suggest that this approach can increase the rate of live births in patients suffering from repeated implantation failures or repeated pregnancy loss. Uterine immune profiling represents a clinical innovation that can significantly improve the performance of medically assisted reproduction treatments through personalized strategies tailored to the local immune profile. Innovation in personalized medicine for assisted reproduction is crucial to improving the success rates of fertility treatments, while reducing the risks and costs associated with ineffective or unnecessary interventions.

Simple FISH-based evaluation of spermatic nuclear architecture shows an abnormal chromosomal organization in balanced chromosomal rearrangement carriers.

INTRODUCTION: Interphasic DNA has a constant three-dimensional conformation, which is particularly striking for spermatic DNA, with distinct chromosomal territories and a constant chromosomal conformation. We hypothesized that this organization is fragile, and that an excess or a lack of chromosomal segments could hinder the genomic structure as a whole. METHODS: Five human male chromosomal translocation carriers and five controls were included. Spermatic DNA spatial organization was studied, in both balanced and unbalanced spermatozoa, with two-dimensional fluorescent in situ hybridization (FISH) via analysis of chromosomes not implicated in the cases' translocations, compared to that of normal controls. Two parameters were studied: the distance between the two telomeric ends of chromosome 1, and the area of the chromosomal territories of chromosomes 1 and 17. RESULTS: Sperm FISH analysis of rearrangement carriers revealed changes in the nuclear architecture compared to that of controls. Inter-telomeric distance and chromosomal territories areas were both significantly increased. DISCUSSION: We show that an excess or lack of chromosomal segments can hinder the normal spatial nuclear architecture in sperm. These results show that nuclear architecture is a fragile assembly, and that local chromosomal abnormalities may impact the nucleus as a whole. This suggests a potential avenue for selection of spermatozoa prior to in vitro fertilization, not only in rearrangement carriers but also in the infertile population at large. Furthermore, we suggest that 2D-FISH could possibly be a useful tool in assessing spermatic nuclear organization in a way to evaluate male fertility.

Double chromosomal translocation in an infertile man: one-step FISH meiotic segregation analysis and reproductive prognosis.

BACKGROUND: The prevalence of chromosomal translocations is 1/500 in the general population. While in the vast majority of cases, carriers have a normal phenotype; they can present with difficulty conceiving due to the presence of a proportion of unbalanced gametes as a consequence of abnormal chromosomal segregation during meiosis. Since complex translocations involve three or more chromosomes, meiotic segregation leads to a greater number of possible combinations which effectively complicate both their study and therapeutic care. CASE PRESENTATION: We report on the case of a male carrier of a complex homogeneous double Robertsonian translocation: 44, XY, der(13;14)(q10;q10),der(21;22)(q10;q10). We studied his meiotic segregation by FISH on spermatozoa from the initial sample, as well as following discontinuous gradient centrifugation and after incubation in an hypo-osmotic solution. CONCLUSION: We report a method to study in a simple single-step manner the meiotic segregation of double Robertsonian translocations in spermatozoa. Further, our results suggest that reproductive prognosis of affected individuals may be markedly improved by HOST-based sperm selection (HBSS).

Potential selection of genetically balanced spermatozoa based on the hypo-osmotic swelling test in chromosomal rearrangement carriers.

Chromosomal translocations and other balanced rearrangements, although usually associated with a normal phenotype, can lead to the transmission of an abnormal unbalanced genome to the offspring. Balanced and unbalanced spermatozoa, being indistinguishable, cannot be selected or deselected for prior to IVF and pre-implantation genetic diagnosis. Spermatozoa from 16 chromosomal rearrangement carriers were studied. After incubation in a hypo-osmotic solution (hypo-osmotic swelling test, or HOST), spermatozoa were fixed on microscope slides. The chromosomally balanced or unbalanced status corresponding to each observed class of flagellar conformation was evaluated through fluorescent in-situ hybridization (FISH). We show here a specific type of spermatozoa, with a distinct flagellar conformation that was associated with a balanced genetic content. HOST is a simple, low-cost and time-honoured procedure initially developed to distinguish immotile viable from non-viable spermatozoa. We demonstrate that it can also be used to identify genetically balanced spermatozoa in chromosomal rearrangement carriers, with a 96% decrease in the proportion of unbalanced spermatozoa after selection. This may potentially improve reproductive prognosis in affected couples if used prior to pre-implantation genetic diagnosis (PGD), and clinical utility and efficacy should be evaluated in further studies.

The Endometrial Immune Profiling May Positively Affect the Management of Recurrent Pregnancy Loss.

Introduction: The endometrial immune profiling is an innovative approach based on the analysis of the local immune reaction occurring in the endometrium at the time of the embryo implantation. By documenting the local immune activation during the period of uterine receptivity, we aim to detect and correct potential imbalances before and at the very beginning of placentation. The main objective of the study was to analyze in women with a history of repeated pregnancy loss (RPL) the association of personalized strategies based on immune dysregulations with live birth rates. The secondary objective was to highlight the main prognostic factors for live births. Methods: This is an observational retrospective analysis of 104 patients with RPL, included between January 2012 and December 2019. Inclusion criteria included a spontaneous fertility with at least three miscarriages, an assessment including a three-dimension ultrasound scan, an endometrial biopsy for uterine immune profiling and a follow-up over at least 6 months with personalized care if indicated after the complete assessment. We defined as a success if the patients had a live birth after the suggested plan, as a failure if the patient either did not get pregnant or experienced a new miscarriage after the targeted therapies. Results: Uterine immune profiling was the only exploration to be significantly associated with a higher live birth rate (LBR) if a dysregulation was identified and treated accordingly (55% vs 45%, p=0.01). On the contrary, an absence of local dysregulation (resulting in an apparently balanced immune environment) was associated with a higher risk of a new miscarriage, suggesting that the cause inducing RPL still needed to be identified. Independently of age and AMH level, dysregulated immune profile is significatively associated with 3 times higher LBR than a non-deregulated profile (OR=3.4 CI 95%1.27-9.84) or five times in case of an overactive profile treated by immunotherapy (OR=5 CI 95% 1.65-16.5). The usage of ART was significantly associated with lower LBR regardless of the presence of a subfertility factor (p=0.012). Personalization of medical care using natural cycle or simple hormonal stimulation is associated with a significantly higher LBR than personalization including ART treatments regardless of maternal age and AMH level (OR= 2.9 CI 95% 1.03-8.88). Conclusion: Our study suggests that some endometrial immune profiles with targeted management of RPL are associated with a higher rate of LBR. ART may be negatively associated with LBR.

Endometrial Immune Profiling: A Method to Design Personalized Care in Assisted Reproductive Medicine.

Objective: To assess the efficiency of the endometrial immune profiling as a method to design personalized care to enhance the pregnancy rate in a large heterogeneous infertile population. We hypothesized that some reproductive failures could be induced by a uterine immune dysregulation which could be identified and corrected with a targeted plan. Design: Prospective cohort study. Setting: Multicentric study. Intervention(s) and Main outcome measure(s): One thousand and seven hundred thirty-eight infertile patients had an immune profiling on a timed endometrial biopsy between 2012 and 2018. This test documented the absence or the presence of an endometrial immune dysregulation and identified its type. In case of dysregulation, a targeted personalized plan was suggested to the treating clinician aiming to supply the anomaly. One year after the test, the clinician was contacted to provide the outcome of the subsequent embryo transfer with the applied suggested plan. Result(s): After testing, 16.5% of the patients showed no endometrial immune dysregulation, 28% had a local immune under-activation, 45% had a local immune over-activation, and 10.5% had a mixed endometrial immune profile. In patients with a history of repeated implantation failures (RIF) or recurrent miscarriages (RM), the pregnancy rate was significantly higher if an endometrial dysregulation was found and the personalized plan applied, compared to the patients with an apparent balanced immune profile (respectively 37.7 and 56% vs. 26.9 and 24%, p < 0.001). In contrast, in good prognosis IVF (in vitro fertilization) subgroup and patients using donor eggs, this difference was not significant between dysregulated and balanced subgroups, but higher pregnancy rates were observed in absence of dysregulation. For patients with immune over-activation, pregnancy rates were significantly higher for patients who had a test of sensitivity, regarding the type of immunotherapy introduced, when compared to the ones who did not (51 vs. 39.9%, p = 0.012). Conclusion(s): Local endometrial immunity appears to be a new and important parameter able to influence the prognosis of pregnancy. Targeted medical care in case of local immune dysregulation resulted in significantly higher pregnancy rates in RIF and RM patients.

Impact of prednisone in patients with repeated embryo implantation failures: Beneficial or deleterious?

INTRODUCTION: Corticotherapy is the leading medication worldwide for patients with history of repeated implantation failures (RIF) after IVF/ICSI. Nevertheless, we still do not know its local mechanism of action, hence its precise indication. Our objective is to document the impact of prednisone on the endometrial expression of immune biomarkers (CD56 cells count, IL-18/TWEAK, IL-15/Fn-14 mRNA ratio) at the time of uterine receptivity in a RIF population. MATERIALS AND METHOD: An endometrial biopsy was realized in the mid luteal phase for immune profiling: IL-15/Fn-14 and IL-18/TWEAK mRNA ratios were determined by quantitative RT-PCR and CD56 mobilization per IHC. Fifty-five patients with a RIF history were diagnosed to have local over-immune activation [high IL-18/TWEAK mRNA ratio, and/or high IL-15/Fn-14 mRNA ratio] likely to impair the implantation process. They underwent a second immune profiling with supplementation of prednisone. A paired comparison of the immune profile before and under prednisone was performed in the subset of patients subsequently pregnant under prednisone. FINDING: In 54.5% of the cases, both immune biomarkers were normalized and in 16.5%, only one was normalized under prednisone. In 29% we observed a paradoxical increase of both immune biomarkers. The IL-18/TWEAK mRNA ratio reflecting the Th-1/Th-2 local equilibrium was significantly reduced (0.29 versus 0.10, p = .004), through very significant increase of TWEAK expression, in patients who were subsequently pregnant under prednisone. CONCLUSION: Testing the response to prednisone in a RIF context may be very useful. Less than half of RIF patients with immune deregulation may be prednisone responders and would benefit from its administration.

Uterine immune profiling for increasing live birth rate: A one-to-one matched cohort study.

BACKGROUND: Embryo implantation remains the main limiting factor in IVF/ICSI program. Endometrial immune remodeling events begin before implantation and are a vital process for pregnancy, preparing future maternal immune tolerance and regulating the placentation process. METHODS: Between 2012 and 2014, 193 patients (analyzed group) enrolled in our IVF program benefitted of an endometrial immune profiling to determine if their uterus was immunologically ready to accept an embryo and, if not, the specific immune mechanisms involved. Subsequently, they had an effective embryo transfer (ET) with personalization of their treatments if an immune deregulation has been diagnosed. Each analyzed patient was paired to the closest patient included in the IVF program according to biological criteria (age, number of mature oocytes, stage and number of transferred embryo), which had no endometrial immune profiling (193 patients, non-analyzed group). FINDING: 78% of analyzed patients had a uterine immune dysregulation and therefore care personalization. Their corresponding live birth rate (LBR) was twice higher than observed in the matched control group with conventional cares (30.5% versus 16.6%, OR: 2.2 [1.27-3.83] p=0.004) with a simultaneous drastic reduction of miscarriages per initiated pregnancy (17.9% versus 43.2%, OR: 0.29 [0.12-0.71], p=0.005). 22% of analyzed patients had no dysregulation. They did not differ from their matched controls for LBR and miscarriages. CONCLUSION: Uterine immune profiling enables an integrated approach of infertility that includes endometrial immunity as a key factor in planning personalized IVF/ICSI treatments. Personalization of treatment according to the woman's uterine immune balance produced a very significantly higher LBR.