Free fetal DNA for non-invasive prenatal diagnosis (NIPD): ethical aspects

Dr Phillipa Brice's accompanying commentary highlights how non-invasive testing of free fetal DNA (ffDNA) in pregnancy could transform women's experiences of antenatal screening and prenatal diagnosis. NIPD is already available for foetal sex, rhesus D blood type and some Mendelian inheritance such as achondroplasia, with tests for aneuploidy detection and Down syndrome being developed. These tests will not pose a risk to the pregnancy and could provide women and couples with definitive information earlier than current methods. The advantages over 'traditional' prenatal screening and diagnosis seem obvious - so is NIPD ethically problematic? Unsurprisingly, a pithy 'yes' or 'no' answer to this question is impossible and would undermine the opportunity for a rich and important discussion of how the ethics of NIPD might depart from 'traditional' testing in pregnancy. But in short, expectations are that NIPD can be conducted ethically if the right conditions are in place, and it is laudable that those working in this field are liaising so closely with ethicists to address emerging concerns as this technology develops.(1) An initial question is whether this technology gives rise to any new ethical questions over and above existing screening, diagnostic or assisted reproductive technologies. Existing debates in prenatal diagnosis, such as the disability rights critique, will continue to be relevant and may be exacerbated. So too will issues of the 'seriousness' threshold for offering PND and the routinisation of testing. Whilst NIPD does not depart too far from these existing issues, there may be important changes to the moral landscape of testing. If offered widely (for suitable conditions), NIPD will effectively become a screening test with a definitive outcome, akin to HIV (human immunodeficiency virus) testing in pregnant women, but one that may lead to termination. We need to decide which method of consent is appropriate and be mindful that a major justification for declining prenatal diagnosis (risk to the pregnancy) will be removed. Overall termination rates may also increase. Women will need sound and unbiased information about NIPD and will require time to reflect before deciding about testing.This article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014

Ethical considerations for choosing between possible models for using NIPD for aneuploidy detection

Recent scientific advances mean the widespread introduction of non-invasive prenatal diagnosis (NIPD) for chromosomal aneuploidies may be close at hand, raising the question of how NIPD should be introduced as part of antenatal care pathways for pregnant women. In this paper we examine the ethical implications of three hypothetical models for using NIPD for aneuploidy in state-funded healthcare systems and assess which model is ethically preferable. In comparing the models we consider their respective timings; how each model would fit with current screening and diagnostic tests offered to pregnant women; the implications of offering NIPD at different stages of pregnancy; and the potential for each model to support reproductive autonomy and informed decision-making. We conclude by favouring a model that would be offered at 11-13 weeks gestation, alongside existing combined screening, provided that this is accompanied by measures to maximise informed decision-making, for example provision of adequate pre- and post-test counselling. Key words: Genetic Screening/Testing, Genetic Counselling/Prenatal Diagnosis; ethics; aneuploidy; Down syndrome.This article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014

Should non-invasiveness change informed consent procedures for prenatal diagnosis?

Empirical evidence suggests that some health professionals believe consent procedures for the emerging technology of non-invasive prenatal diagnosis (NIPD) should become less rigorous than those currently used for invasive prenatal testing. In this paper, we consider the importance of informed consent and informed choice procedures for protecting autonomy in those prenatal tests which will give rise to a definitive result. We consider whether there is anything special about NIPD that could sanction a change to consent procedures for prenatal diagnosis or otherwise render informed decision-making less important. We accept the claim that the absence of risk of miscarriage to some extent lessens the gravity of the decision to test compared with invasive methods of testing. However, we also claim that the definitive nature of the information received, and the fact that the information can lead to decisions of great significance, makes NIPD an important choice. This choice should only be made by means of a rigorous and appropriately supported decision-making process (assuming that this is what the pregnant woman wants). We conclude that, on balance, consent procedures for NIPD should mirror those for invasive testing, albeit without the need to emphasise procedure-related risk. Keywords: autonomy; decision making; informed choice; informed consent; prenatal diagnosis.This article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014

Will the introduction of non-invasive prenatal diagnostic testing erode informed choices? An experimental study of health care professionals

Objective. Informed choice is a fundamental concept within prenatal care. The present study assessed the extent to which the introduction of non-invasive prenatal diagnosis (NIPD) of Down's syndrome may undermine the process of making informed choices to undergo prenatal testing or screening for Down's syndrome by altering the quality and quantity of pre-test counselling. Methods. 231 obstetricians and midwives were randomly allocated one of three vignettes, each describing a different type of test: (a) invasive prenatal diagnosis (IPD), (b) non-invasive prenatal diagnosis (NIPD) or (c) Down's syndrome screening (DSS). Participants were then asked to complete a questionnaire assessing (1) the information considered important to communicate to women, (2) whether test offer and uptake should take place on different days, and (3) whether signed consent forms should be obtained prior to testing. Results. Across the three test types, five out of the seven presented topics were considered equally important to communicate, including the information that testing is the woman's choice. Compared with participants receiving the IPD vignette, those receiving the NIPD and DSS vignettes were less likely to report that counselling and testing should occur on different days (IPD 94.7% versus 74.1% and 73.9% for NIPD and DSS respectively, p = .001) and that written consent was a necessity (IPD 96.1% versus 68.3% and 75.4% for NIPD and DSS respectively, p < .001). Conclusion. This study provides the first empirical evidence to demonstrate that practitioners may view the consent process for NIPD differently to IPD. There is potential for the introduction of NIPD to undermine women making informed choices in the context of prenatal diagnostic testing for conditions like DS. Practice implications. Given the importance of informed choice in reproductive decision-making, implementation of any programme based on NIPD should be designed to facilitate this. Keywords: Informed choice; Prenatal; Down's syndrome; Non-invasive testingThis article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014

Comparison of the myocardial clearance of endothelial progenitor cells injected early versus late into reperfused or sustained occlusion myocardial infarction

Stem cell transplantation following AMI has shown promise for the repair or reduction of the amount of myocardial injury. There is some evidence that these treatment effects appear to be directly correlated to cell residence time. This study aims to assess the effects of (a) the timing of stem cell injection following myocardial infarction, and (b) flow milieu, on cell residence times at the site of transplantation by comparing three time points (day of infarction, week 1 and week 4-5), and two models of acute myocardial infarction (sustained occlusion or reperfusion). Twenty-one dogs received 2 injections of 30 million endothelial progenitor cells. The first injections were administered by epicardial (n = 8) or endocardial injection (n = 13) either on the day of infarction (n = 15) or at 1 week (n = 6). The second injections were administered by only endocardial injection (n = 18) 4 weeks following the first injection. Cell clearance half-lives were comparable between early and late injections. However, transplants into sustained occlusion infarcts resulted in slower cell clearance 77.1 ± 6.1 (n = 18) versus reperfused 59.4 ± 2.9 h (n = 21) p = 0.009. Sustained occlusion infarcts had longer cell retention in comparison to reperfusion whereas the timing of injection did not affect clearance rates. If the potential for myocardial regeneration associated with cell transplantation is, at least in part, linked to cell residence times, then greater benefit may be observed with transplants into infarcts associated with persistent coronary artery occlusion. © 2012 The Author(s)

Biomarker testing in oncology - Requirements for organizing external quality assessment programs to improve the performance of laboratory testing:revision of an expert opinion paper on behalf of IQNPath ABSL

In personalized medicine, predictive biomarker testing is the basis for an appropriate choice of therapy for patients with cancer. An important tool for laboratories to ensure accurate results is participation in external quality assurance (EQA) programs. Several providers offer predictive EQA programs for different cancer types, test methods, and sample types. In 2013, a guideline was published on the requirements for organizing high-quality EQA programs in molecular pathology. Now, after six years, steps were taken to further harmonize these EQA programs as an initiative by IQNPath ABSL, an umbrella organization founded by various EQA providers. This revision is based on current knowledge, adds recommendations for programs developed for predictive biomarkers by in situ methodologies (immunohistochemistry and in situ hybridization), and emphasized transparency and an evidence-based approach. In addition, this updated version also has the aim to give an overview of current practices from various EQA providers

Modeling recursive RNA interference.

An important application of the RNA interference (RNAi) pathway is its use as a small RNA-based regulatory system commonly exploited to suppress expression of target genes to test their function in vivo. In several published experiments, RNAi has been used to inactivate components of the RNAi pathway itself, a procedure termed recursive RNAi in this report. The theoretical basis of recursive RNAi is unclear since the procedure could potentially be self-defeating, and in practice the effectiveness of recursive RNAi in published experiments is highly variable. A mathematical model for recursive RNAi was developed and used to investigate the range of conditions under which the procedure should be effective. The model predicts that the effectiveness of recursive RNAi is strongly dependent on the efficacy of RNAi at knocking down target gene expression. This efficacy is known to vary highly between different cell types, and comparison of the model predictions to published experimental data suggests that variation in RNAi efficacy may be the main cause of discrepancies between published recursive RNAi experiments in different organisms. The model suggests potential ways to optimize the effectiveness of recursive RNAi both for screening of RNAi components as well as for improved temporal control of gene expression in switch off-switch on experiments

Variation in dermcidin expression in a range of primary human tumours and in hypoxic/oxidatively stressed human cell lines.

Dermcidin acts as a survival factor in a variety of cancer cell lines under hypoxia or oxidative stress. The aim of this study was to evaluate dermcidin expression in cell lines following simulation of tumour microenvironmental conditions and in a range of primary tumours. Tumour tissues were collected from patients with oesophageal (28 samples), gastric (20), pancreatic (five), bile duct (one) and prostatic (52) carcinomas as well as 30 benign tissue samples, for assessment of dermcidin mRNA levels using real-time PCR. Dermcidin expression was assessed in prostatic and pancreatic cancer cell lines, with and without induction of hypoxia or oxidative stress. Dermcidin mRNA expression was very low or absent in both unstressed and stressed prostate cell lines. None of the primary prostate tissue, benign or malignant, expressed dermcidin mRNA. Only two (4%) of the gastro-oesophageal cancer samples expressed moderate quantities of dermcidin mRNA. However, three (60%) of the pancreatic cancer samples and the single cholangiocarcinoma specimen had moderate/high levels of dermcidin expression. Of the two pancreatic cancer cell lines, one expressed dermcidin moderately but neither showed a response to hypoxia or oxidative stress. Expression of dermcidin in human primary tumours appears highly variable and is not induced substantially by hypoxia/oxidative stress in cell line model systems. The relationship of these findings to dermcidin protein levels and cell survival remains to be determined

CRISPR-Cas9 screens in human cells and primary neurons identify modifiers of C9ORF72 dipeptide-repeat-protein toxicity.

Hexanucleotide-repeat expansions in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (c9ALS/FTD). The nucleotide-repeat expansions are translated into dipeptide-repeat (DPR) proteins, which are aggregation prone and may contribute to neurodegeneration. We used the CRISPR-Cas9 system to perform genome-wide gene-knockout screens for suppressors and enhancers of C9ORF72 DPR toxicity in human cells. We validated hits by performing secondary CRISPR-Cas9 screens in primary mouse neurons. We uncovered potent modifiers of DPR toxicity whose gene products function in nucleocytoplasmic transport, the endoplasmic reticulum (ER), proteasome, RNA-processing pathways, and chromatin modification. One modifier, TMX2, modulated the ER-stress signature elicited by C9ORF72 DPRs in neurons and improved survival of human induced motor neurons from patients with C9ORF72 ALS. Together, our results demonstrate the promise of CRISPR-Cas9 screens in defining mechanisms of neurodegenerative diseases