588 research outputs found

    Paternal factors in recurrent miscarriage : a role beyond conception

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    In normal pregnancy the fetus, although a semi-allograft, is tolerated by the maternal immune system. It has been suggested that an inadequate maternal allo-immune response to the paternal antigens of the fetus is responsible for a proportion of the unexplained recurrent miscarriage. In chapter 2 we provide an overview on the possible role of the HLA system in recurrent miscarriage. No consistent conclusions can be drawn since the observed odd ratios found were relatively small and the risk of bias in the selected studies was high. In chapter 3 we compared the genetic polymorphisms of HLA-G in women with recurrent miscarriage with women with uneventful pregnancy. The HLA-G UTR-4 haplotype was less frequently observed in women with recurrent miscarriage, suggesting an immunoregulatory role of this haplotype. The combined results from chapter 4, chapter 6 and chapter 7 suggest that in a portion of women with unexplained recurrent miscarriage antibody-mediated rejection of the fetal allograft may play a role. We showed in chapter 8 that human seminal plasma contains all kinds of immunoregulatory factors and has an immunomodulatory effect on T cells. In chapter 9 a matched case-control study practicing oral sex was negatively associated with the occurrence of recurrent miscarriage. department of Gynaecology and Obstetrics Leiden University Medical Center, Nationaal Referentie Centrum voor Histocompatibiliteit, Stichting Oranjekliniek, Stichting NVLE Fonds, Stichting HELLP, Chipsoft, BMA Mosos, VPS Diagnostics, RabobankLUMC / Geneeskund

    HLA-C antibodies in women with recurrent miscarriage suggests that antibody mediated rejection is one of the mechanisms leading to recurrent miscarriage

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    AbstractHLA-C is the only polymorphic classical HLA I antigen expressed on trophoblast cells. It is known that higher incidence of C4d deposition on trophoblast cells is present in women with recurrent miscarriage. C4d is a footprint of antibody-mediated classical complement activation. Therefore, this study hypothesize that antibodies against HLA-C may play a role in the occurrence of unexplained consecutive recurrent miscarriage.Present case control study compared the incidence of HLA-C specific antibodies in 95 women with at least three consecutive miscarriages and 105 women with uneventful pregnancy. In the first trimester of the next pregnancy, presence and specificity of HLA antibodies were determined and their complement fixing ability. The incidence of HLA antibodies was compared with uni- and multivariate logistic regression models adjusting for possible confounders.Although in general a higher incidence of HLA antibodies was found in women with recurrent miscarriage 31.6% vs. in control subjects 9.5% (adjusted OR 4.3, 95% CI 2.0–9.5), the contribution of antibodies against HLA-C was significantly higher in women with recurrent miscarriage (9.5%) compared to women with uneventful pregnancy (1%) (adjusted OR 11.0, 95% CI 1.3–89.0). In contrast to the control group, HLA-C antibodies in the recurrent miscarriage group were more often able to bind complement.The higher incidence of antibodies specific for HLA-C in women with recurrent miscarriage suggests that HLA-C antibodies may be involved in the aetiology of unexplained consecutive recurrent miscarriage

    Plasma miRNAs as biomarkers for endometriosis

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    STUDY QUESTION: Can plasma miRNAs be used for the non-invasive diagnosis of endometriosis in infertile women? SUMMARY ANSWER: miRNA-based diagnostic models for endometriosis failed the test of independent validation. WHAT IS KNOWN ALREADY: Circulating miRNAs have been described to be differentially expressed in patients with endometriosis compared with women without endometriosis, suggesting that they could be used for the non-invasive diagnosis of endometriosis. However, these studies have shown limited consistency or conflicting results, and no miRNA-based diagnostic test has been validated in an independent patient cohort. STUDY DESIGN, SIZE, DURATION: We performed genome-wide miRNA expression profiling by small RNA sequencing to identify a set of plasma miRNAs with discriminative potential between patients with and without endometriosis. Expression of this set of miRNAs was confirmed by RT-qPCR. Diagnostic models were built using multivariate logistic regression with stepwise feature selection. In a final step, the models were tested for validation in an independent patient cohort. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Plasma of all patients was available in the biobank of the Leuven Endometriosis Centre of Excellence. Biomarker discovery and model development were performed in a discovery cohort of 120 patients (controls= 38, endometriosis= 82), and models were tested for validation in an independent cohort of 90 patients (controls= 30, endometriosis= 60). RNA was extracted with the miRNeasy Plasma Kit. Genome-wide miRNA expression analysis was done by small RNA sequencing using the NEBNext small RNA library prep kit and the NextSeq 500 System. cDNA synthesis and qPCR were performed using the Qiagen miScript technology. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a set of 42 miRNAs with discriminative power between patients with and without endometriosis based on genome-wide miRNA expression profiling. Expression of 41 miRNAs was confirmed by RT-qPCR, and 3 diagnostic models were built. Only the model for minimal-mild endometriosis (Model 2: hsa-miR-125b-5p, hsa-miR-28-5p and hsa-miR-29a-3p) had diagnostic power above chance performance in the independent validation (AUC= 60%) with an acceptable sensitivity (78%) but poor specificity (37%). LIMITATIONS, REASONS FOR CAUTION: The diagnostic models were built and tested for validation in two patient cohorts from a single tertiary endometriosis centre. Further validation tests in large cohorts with patients from multiple endometriosis centres are needed. WIDER IMPLICATION OF THE FINDINGS: Our study supports a possible biological link between certain miRNAs and endometriosis, but the potential of these miRNAs as clinically useful biomarkers is questionable in women with infertility. Large studies in well-described patient cohorts, with rigorous methodology for miRNA expression analysis, sufficient statistical power and an independent validation step, are necessary to answer the question of whether miRNAs can be used as diagnostics markers for endometriosis

    Principles guiding embryo selection following genome-wide haplotyping of preimplantation embryos.

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    STUDY QUESTION How to select and prioritize embryos during PGD following genome-wide haplotyping? SUMMARY ANSWER In addition to genetic disease-specific information, the embryo selected for transfer is based on ranking criteria including the existence of mitotic and/or meiotic aneuploidies, but not carriership of mutations causing recessive disorders. WHAT IS KNOWN ALREADY Embryo selection for monogenic diseases has been mainly performed using targeted disease-specific assays. Recently, these targeted approaches are being complemented by generic genome-wide genetic analysis methods such as karyomapping or haplarithmisis, which are based on genomic haplotype reconstruction of cell(s) biopsied from embryos. This provides not only information about the inheritance of Mendelian disease alleles but also about numerical and structural chromosome anomalies and haplotypes genome-wide. Reflections on how to use this information in the diagnostic laboratory are lacking. STUDY DESIGN, SIZE, DURATION We present the results of the first 101 PGD cycles (373 embryos) using haplarithmisis, performed in the Centre for Human Genetics, UZ Leuven. The questions raised were addressed by a multidisciplinary team of clinical geneticist, fertility specialists and ethicists. PARTICIPANTS/MATERIALS, SETTING, METHODS Sixty-three couples enrolled in the genome-wide haplotyping-based PGD program. Families presented with either inherited genetic variants causing known disorders and/or chromosomal rearrangements that could lead to unbalanced translocations in the offspring. MAIN RESULTS AND THE ROLE OF CHANCE Embryos were selected based on the absence or presence of the disease allele, a trisomy or other chromosomal abnormality leading to known developmental disorders. In addition, morphologically normal Day 5 embryos were prioritized for transfer based on the presence of other chromosomal imbalances and/or carrier information. LIMITATIONS, REASONS FOR CAUTION Some of the choices made and principles put forward are specific for cleavage-stage-based genetic testing. The proposed guidelines are subject to continuous update based on the accumulating knowledge from the implementation of genome-wide methods for PGD in many different centers world-wide as well as the results of ongoing scientific research. WIDER IMPLICATIONS OF THE FINDINGS Our embryo selection principles have a profound impact on the organization of PGD operations and on the information that is transferred among the genetic unit, the fertility clinic and the patients. These principles are also important for the organization of pre- and post-counseling and influence the interpretation and reporting of preimplantation genotyping results. As novel genome-wide approaches for embryo selection are revolutionizing the field of reproductive genetics, national and international discussions to set general guidelines are warranted. STUDY FUNDING/COMPETING INTEREST(S) The European Union's Research and Innovation funding programs FP7-PEOPLE-2012-IAPP SARM: 324509 and Horizon 2020 WIDENLIFE: 692065 to J.R.V., T.V., E.D. and M.Z.E. J.R.V., T.V. and M.Z.E. have patents ZL910050-PCT/EP2011/060211-WO/2011/157846 (‘Methods for haplotyping single cells’) with royalties paid and ZL913096-PCT/EP2014/068315-WO/2015/028576 (‘Haplotyping and copy-number typing using polymorphic variant allelic frequencies’) with royalties paid, licensed to Cartagenia (Agilent technologies). J.R.V. also has a patent ZL91 2076-PCT/EP20 one 3/070858 (‘High throughout genotyping by sequencing’) with royalties paid

    Definition and criteria for diagnosing cesarean scar disorder.

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    IMPORTANCE: Approximately 60% of women develop a uterine niche after a cesarean delivery (CD). A niche is associated with various gynecological symptoms including abnormal uterine bleeding, pain, and infertility, but there is little consensus in the literature on the distinction between the sonographic finding of a niche and the constellation of associated symptoms. OBJECTIVE: To achieve consensus on defining the clinical condition that constitutes a symptomatic uterine niche and agree upon diagnostic criteria and uniform nomenclature for this condition. DESIGN, SETTING, AND PARTICIPANTS: A consensus based modified electronic Delphi (eDelphi) study, with a predefined Rate of Agreement (RoA) of 70% or higher. Experts were selected according to their expertise with niche-related consultations, publications, and participation in expert groups and received online questionnaires between November 2021 and May 2022. MAIN OUTCOMES AND MEASURES: Definition, nomenclature, symptoms, conditions to exclude, and diagnostic criteria of an illness caused by a symptomatic uterine niche. RESULTS: In total, 31 of the 60 invited experts (51.7%) participated, of whom the majority worked in university-affiliated hospitals (28 of 31 [90.3%]), specialized in benign gynecology (20 of 31 [64.5%]), and worked in Europe (24 of 31 [77.4%]). Three rounds were required to achieve consensus on all items. All participants underlined the relevance of a new term for a condition caused by a symptomatic niche and its differentiation from a sonographic finding only. Experts agreed to name this condition cesarean scar disorder, defined as a uterine niche in combination with at least 1 primary or 2 secondary symptoms (RoA, 77.8%). Defined primary symptoms were postmenstrual spotting, pain during uterine bleeding, technical issues with catheter insertion during embryo transfer, and secondary unexplained infertility combined with intrauterine fluid. Secondary symptoms were dyspareunia, abnormal vaginal discharge, chronic pelvic pain, avoiding sexual intercourse, odor associated with abnormal blood loss, secondary unexplained infertility, secondary infertility despite assisted reproductive technology, negative self-image, and discomfort during participation in leisure activities. Consensus was also achieved on certain criteria that should be met and conditions that should be excluded before making the diagnosis. CONCLUSIONS AND RELEVANCE: In this modified Delphi study, a panel of 31 international niche experts reached consensus for the constellation of symptoms secondary to a uterine niche and named it cesarean scar disorder

    Non-destructive Assessment of Quality and Yield for Grass-Breeding

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    Selection of cultivars has, until now, been based mainly on dry matter (DM) yields because of the high costs of sampling and chemical analysis. Imaging spectroscopy could reduce costs by limiting sampling and harvesting of individual plots to reference samples (Schut et al., accepted). In this study, the prediction accuracy of DM yields and chemical composition with imaging spectroscopy is evaluated for cultivar selection purposes

    Low Mannose-Binding Lectin Concentration Is Associated with Severe Infection in Patients with Hematological Cancer Who Are Undergoing Chemotherapy

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    Background. Mannose-binding lectin (MBL) is a serum lectin involved in innate immune response. Low serum MBL concentration may constitute a risk factor for infection in patients receiving myelosuppressive chemotherapy. Methods. We conducted a prospective, observational study that assessed MBL concentration as a risk factor for infection in patients with hematological malignancy who were hospitalized to undergo at least 1 chemotherapy cycle. MBL deficiency was defined using an algorithm that considered the serum MBL concentration and the MBL genotype. The primary end point was the ratio of duration of febrile neutropenia to the duration of neutropenia. Secondary end points included the incidence of severe infection (e.g., sepsis, pneumonia, bacteremia, and invasive fungal infection). Logistic regression analysis was conducted, and Fisher's exact test was used to analyze binary outcomes, and Kaplan-Meier estimates and log rank tests were used for time-to-event variables. Results. We analyzed 255 patients who received 569 cycles of chemotherapy. The median duration of neutropenia per cycle was 7 days (interquartile range, 0-13 days). Sixty-two patients (24%) were found to have MBL deficiency. Febrile neutropenia occurred at least once in 200 patients. No difference in the primary outcome was seen. The incidence of severe infection was higher among MBL-deficient patients than among non-MBL-deficient patients (1.96 vs. 1.34 cases per 100 days for analysis of all patients [P = .008] and 1.85 vs. 0.94 cases per 100 days excluding patients with acute leukemia [P < .001]). Conclusions. MBL deficiency does not predispose adults with hematological cancer to more-frequent or more-prolonged febrile episodes during myelosuppressive chemotherapy, but MBL-deficient patients have a greater number of severe infections and experience their first severe infection earlier, compared with nondeficient patient

    Older patients' experiences with and attitudes towards an oncogeriatric pathway: A qualitative study

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    INTRODUCTION: To tailor treatment for older patients with cancer, an oncogeriatric care pathway has been developed in the Leiden University Medical Center. In this care pathway a geriatric assessment is performed and preferences concerning cancer treatment options are discussed. This study aimed to explore patient experiences with and attitudes towards this pathway.MATERIALS AND METHODS: A qualitative study was performed using an exploratory descriptive approach. Individual face-to-face semi-structured interviews were conducted with older patients (≥70 years) who had followed the oncogeriatric care pathway in the six months prior to the interview. The interviews were audio-recorded and transcribed verbatim. The transcripts were analyzed inductively using thematic analysis.RESULTS: After interviews with 14 patients with a median age of 80 years, three main themes were identified. (1) Patients' positive experiences with the oncogeriatric pathway: Patients appreciated the attitudes of the healthcare professionals and felt heard and understood. (2) Unmet information needs about the oncogeriatric care pathway: Patients experienced a lack of information about the aim and process. (3) Incomplete information for decision-making: Most patients were satisfied with decision-making process. However, treatment decisions had often been made before oncogeriatric consultation. No explicit naming and explaining of different available treatment options had been provided, nor had risk of physical or cognitive decline during and after treatment been addressed.DISCUSSION: Older patients had predominately positive attitudes towards the oncogeriatric care pathway. Most patients were satisfied with the treatment decision. Providing information on the aim and process of the care pathway, available treatment options, and treatment-related risks of cognitive and physical decline may further improve the oncogeriatric care pathway and the decision-making process.</p
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