MICA: The role of placental infection in adverse pregnancy outcome.

Lead Research Organisation: University of Cambridge
Department Name: Obstetrics and Gynaecology

Abstract

The context for this study is that there are >5 million births in the EU and >4 million births in the USA and severe adverse outcome of pregnancy is relatively common. For example, in the UK alone, >4000 infants are stillborn per year. The majority of adverse outcomes occur to women who lack known risk factors. Poor placental function is thought to be responsible for the majority of stillbirths (the placenta is the "afterbirth" and is critically important for normal pregnancy). The complications which lead to stillbirth are also associated with infant mortality, disability and, through a poor prenatal environment, ill health in later life. However, the underlying cause of placental dysfunction leading to these complications remains obscure. Infection is clearly one of the major possible explanations when considering possible causes of dysfunction of an organ. Multiple studies have reported high rates of placental inflammation in pregnancies with adverse outcome. Others have reported associations between the presence of antibodies to infectious agents in the mother's blood during pregnancy and the risk of outcomes such as pre-eclampsia (high blood pressure and abnormal kidney function during pregnancy). Others have shown that infection of placental cells in culture with certain bacteria or viruses impairs their function. However, the quality of the evidence around both placental inflammation and placental infection is generally poor. Furthermore, recent developments in the analysis of genetic material have generated powerful new tools to identify the presence of infectious agents in tissue and these have not previously been applied to studying the possible role of placental infection in causing pre-eclampsia and poor fetal growth.

We have been conducting a study since January 2008 (funded by the NIHR Cambridge Comprehensive Biomedical Research Centre). We have recruited women having first pregnancies at the time of their first scan. We obtain blood samples at around 12, 20, 28 and 36 weeks of pregnancy. We also obtain samples of the placenta following birth. We perform extra research scans so that we have detailed information on both the women experiencing complications and the controls with whom they will be compared. By the start of this project, we will have data and samples from more than 4,000 women who have completed the study and this provides a unique and powerful resource to identify whether infection of the placenta is a determinant of common pregnancy complications (pre-eclampsia and poor growth of the baby). Our approach is (1) to detect the presence of genetic material (DNA or RNA) for infectious agents in the placenta, (2) to measure markers of infection and inflammation in the stored blood samples, and (3) to determine whether inflammation in the placenta is more common in complicated pregnancies. Critically, we have also enlisted internationally recognised experts (from the renowned Wellcome Trust Sanger Institute) in the technology of detecting infectious agents (bacteria, viruses etc) in tissue samples.

This project could uncover such a role for a currently recognised infectious agent, or it could even identify if these complications are being caused by some currently unrecognised bacterium or virus. Identification of previously unrecognised infectious causes of disease has been critical in medicine in the last 30 years. Recognition of the role of a bacterium (Helicobacter pylori) transformed the management of peptic ulcer disease and recognition of the role of a virus (human papilloma virus) in cervical cancer has led to vaccination as a preventative approach. If the mystery of adverse pregnancy outcome is partly explained by infection, this could lead to similarly dramatic changes in understanding and generate new approaches to improving the health of mothers and babies.

Technical Summary

Adverse pregnancy outcome is often ascribed to "placental dysfunction". However, there is limited mechanistic understanding of the underlying cause. Multiple lines of evidence indicate that clinically unrecognized infection of the placenta is a plausible cause of placental inflammation and dysfunction, but definitive evidence is currently lacking. Since January 2008, we have been conducting a prospective cohort study of unselected nulliparous women attending the Rosie Hospital for antenatal care (funded by the Women's Health theme of the NIHR Cambridge Biomedical Research Centre). Women are recruited at the time of their first ultrasound examination. Participation involves obtaining maternal blood (for serum and plasma) at the first scan (typically ~12 weeks) and at 20, 28, and 36 weeks, plus ultrasound examinations at the same intervals. Following delivery, the placenta and membranes are sampled by a trained technician. We have recruited 4,544 women and all sample and data collection will be complete by May 2013. We will have complete blood and scan data from ~4,250 women and placental samples from ~4,000. We will use these samples to test our hypothesis that placental infection is involved in the aetiology of pre-eclampsia and/or fetal growth restriction (cases). We have the following specific aims: 1. To compare the frequency of detection of nucleic acids encoding for infectious agents in the placenta in cases and controls matched for key maternal and obstetric characteristics. 2. To compare (i) the type, appearance and level of immunoglobulins to infectious agents, and (ii) the level of cytokines associated with placental inflammation; in maternal blood at ~12, 20, 28 and 36 weeks gestational age in cases, in comparison with a common control group of randomly selected women from the same prospectively defined cohort. 3. To quantify placental inflammation (by histopathological and stereological assessment) in the same cases and matched controls, above.

Planned Impact

The work proposed in this application has the potential to have significant societal and economic impact, affecting both patients and the wider public.

The work could lead to improvements in health and well-being in several ways, with multiple parties, including patients and the public benefiting from the proposed research. One of the most natural responses following a severe adverse outcome of pregnancy is to ask why it happened. Our lack of understanding of the basic mechanisms of major placentally related complications of pregnancy (pre-eclampsia, fetal growth restriction and placental abruption) is intensely frustrating for the families who suffer the consequences, such as stillbirth, or admission of a mother to intensive care. Mechanistic understanding of the underlying cause would be viewed very positively and in itself lead to an improvement in well-being, even if there was not an immediate practical application.

Professor Smith has taken part in two receptions for MPs in Westminster hosted by the Stillbirth and Neonatal Death Society (SANDS) and has also gave evidence to an Inquiry by the National Assembly for Wales on rates of Stillbirth in Wales. A frequent view expressed in both political environments was that the magnitude of research activity in this area was not commensurate with the magnitude of the clinical problem. High-quality research in this area may therefore inform public policy in women's health.

Moreover, if the study is successful in identifying infectious causes of complicated pregnancy, this could improve health directly by leading to new methods of prevention and treatment. It is possible that currently unrecognised infectious agents cause some complications. If so, this could lead to diagnostic (e.g. serological tests), curative (e.g. anti-viral therapy) or preventative (e.g. vaccination) strategies. There are clear past examples where this has been the case. The identification of the role of H. pylori in peptic ulcer disease led both to new diagnostic tests and treatment. The identification of the role of HPV in cervical cancer has led to improved risk stratification of women with abnormal smears (by combining cytology with molecular assessment of the presence of oncogenic strains of the virus) and to a vaccination programme which is expected to have a major impact on the disease.

As well as the personal experience of disease, improvements in these areas could have health economic impacts. Over 800,000 women become pregnant each year in the UK. Given a 1% rate of severe pre-eclampsia, 8,000 pregnant women a year become acutely unwell during pregnancy due to pre-eclampsia, requiring intra-venous magnesium sulphate, with some also requiring expensive medical interventions such as emergency caesarean delivery or admission to intensive care. There are also very substantial costs (both short and long term) related to preterm birth secondary to both pre-eclampsia and fetal growth restriction. Better diagnostic, curative and/or preventative approaches would potentially be self-financing through reduced costs of care, both in the short and long term.

Finally, the project has considerable potential to lead to benefits to the wealth of the UK. Although our industrial partner has a head office in the US, Alere have a very significant UK base. The company was previously called Inverness Medical UK Ltd and maintains a large UK presence. Generation of new IP during this project may be commercially exploitable and is likely to attract research and development investment. This would be beneficial for Cambridge University and, hence, have direct benefits for the UK. However, given Alere's significant UK presence, positive effects of new IP for Alere would also be beneficial for the wider UK economy.

Publications

10 25 50
 
Description The evaluation and development of novel diagnostic methods to understand and prevent placentally-related complications of human pregnancy
Amount £2,764,336 (GBP)
Funding ID 215524/Z/19/Z 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2020 
End 07/2025
 
Title Development of improved method for 18S amplification of DNA from eukaryotic microbiota in human tissue samples 
Description The grant includes aiming to detect the presence of eukaryotic microbiota in the placenta comparing cases of preeclampsia and fetal growth restriction with controls. This involves amplification of the 18S gene using specific primers and a blocking probe for the host signal. We employed the protocol described by the Earth Microbiome Project, an international collaborative group. However, when we applied their methods to human samples which had been "spiked" with a positive control (plasmodia falciparum or toxoplasma gondii) we also observed strong signals in non-spiked samples. We then modified the Earth Microbiome Project protocol, varying the use of the blocking primer and using dual index rather than single index primers. Using our modified method, our assay was now able to detect the presence of just a single genome copy of a given eukaryotic microbiota in 25mg of human placenta. We believe that this method has significant potential in the analysis of human tissue samples for pathogens. The method has been presented at an international meeting (Society for Reproductive 2017 Investigation, Orlando, FL, USA) and a full paper has been submitted for publication. 
Type Of Material Technology assay or reagent 
Year Produced 2017 
Provided To Others? Yes  
Impact It is too early for the method to have been widely applied. 
 
Title Fetal inheritance of chromosomally integrated human herpesvirus 6 predisposes the mother to pre-eclampsia 
Description Sequencing data in the above paper (doi 10.1038/s41564-020-0711-3) 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
Impact Only recently published 
 
Title Human placenta has no microbiome but can contain potential pathogens 
Description Sequence data from the placenta - 16S amplicon sequencing and metagenomics 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact A lot of scientific, press and lay interest as this is a contentious area of research 
 
Title Placental RNASeq data 
Description RNASeq data from normal human pregnancy 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact None to date as only recently published. 
 
Title Whole genome sequencing 
Description Whole genome sequencing to search for pathogens in the placenta 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? No  
Impact None yet as not published 
 
Description Collaboration with Pfizer Bacterial Vaccines 
Organisation Pfizer Global R & D
Country United States 
Sector Private 
PI Contribution We identified pregnancies with a bacterial species (GBS) in the placenta through our MRC Challenge grant. We will provide Pfizer with serum samples from these women and controls to determine whether the presence of GBS is related to maternal antibody levels.
Collaborator Contribution They will transport the samples at their expense and analyse them for 6 different GBS strain specific antibodies.
Impact None yet.
Start Year 2020
 
Description Sequencing Core 
Organisation Cancer Research UK Cambridge Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Unique biological samples for sequence analysis
Collaborator Contribution Next generation sequencing
Impact Lots of new sequencing data, still being analysed
Start Year 2013
 
Description Clinical Microbiology Departmental Lunchtime Talk, University of Cambridge 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Professor Smith was invited by the registrar who organises the lunchtime talks to present to the Clinical Microbiology Department 17 September. The title of his talk was 'Molecular infections in neonates'. Susanne Lager also presented with Prof Smith.
Year(s) Of Engagement Activity 2015
 
Description EAOGS Autumn meeting, Cambridge 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Professor Smith was personally invited to present as part of the EAOGS Autumn meeting 17 October in Cambridge. The title of his talk was 'The future of screening for fetal growth restriction'.
Year(s) Of Engagement Activity 2015
 
Description IFPA Japan - Dr Susanne Lager poster presentation 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager was successful in her abstract submission for a poster entitled "Viral nucleic acids in human placenta and pregnancy complications" Susanne Lager1, Marcus C. de Goffau2, Judith Breuer3, Sharon J. Peacock1,4, Julian Parkhill2, D. Stephen Charnock-Jones1, Gordon C.S. Smith1 1University of Cambridge, Cambridge, United Kingdom. 2Wellcome Trust Sanger Institute, Hinxton, United Kingdom. 3University College London, London, United Kingdom. 4London School of Hygiene & Tropical Medicine, London, United Kingdom for presentation at the International Federation of Placenta Associations (IFPA) conference held 21-24 September 2018 in Tokyo, Japan.
Year(s) Of Engagement Activity 2018
URL http://ifpa2018.umin.jp/
 
Description Lecture and visit to Illumina, Redwood City, USA 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Invited to visit and present a lecture at Illumina. Research collaboration discussions also took place.
Year(s) Of Engagement Activity 2016
 
Description Lecture to Illumina sites worldwide 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Third sector organisations
Results and Impact I visited the HQ of Illumina in San Diego CA, USA, a biotech company which leads the world in generating consumables and equipment for Next Generation Sequencing. I was asked to give a lecture in their "Get Inspired" series (March 7th, 2018). This is broadcast live to all the Illumina sites worldwide. Such lecturers are given ~6 times per year. We had already established Confidentiality Disclosure Agreements and Material Transfer Agreements. We are now working towards a significant collaboration around plasma RNA-Seq. I presented some of our initial findings using plasma RNA-Seq funded, in part, by the MRC Challenge grant.
Year(s) Of Engagement Activity 2018
 
Description Poster presentation - SRI Conference 2017 (Dr Susanne Lager) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager - poster presentation at the Society for Reproductive Investigation 64th Annual Scientific Meeting 15-18 March, 2017, Hilton Orlando Bonnet Creek, USA. Authors: Susanne Lager, Marcus de Goffau, Sharon J Peacock, Julian Parkhill, D Stephen Charnock-Jones, Gordon CS Smith. Title: Pre-Eclampsia, Fetal Growth Restriction and Pre-Term Birth Are Not Associated with Placental Infection with Eukaryotic Microbiota.
Year(s) Of Engagement Activity 2017
URL http://www.sri-online.org/meetings-calendar/2017
 
Description Poster presentation - SRI Conference 2017 (Dr Susanne Lager) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager - poster presentation at the Society for Reproductive Investigation 64th Annual Scientific Meeting 15-18 March, 2017, Hilton Orlando Bonnet Creek, USA. Authors: Susanne Lager, Marcus de Goffau, Sharon J Peacock, Julian Parkhill, D Stephen Charnock-Jones, Gordon CS Smith. Title: Terminal Villi of the Human Placenta Have No Core Microbiome.
Year(s) Of Engagement Activity 2017
URL http://www.sri-online.org/meetings-calendar/2017
 
Description RCOG Annual Academic Award presentation, London 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Professor Gordon Smith invited to give a presentation as part of the award ceremony where he was presented with the RCOG Annual Academic Award. Title 'Screening for adverse pregnancy outcome: the future' given 2 March
Year(s) Of Engagement Activity 2017
 
Description SRI - Conference abstract 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Francesca Gaccioli presented accepted abstract at the SRI conference held 12-16 March 2019 in Paris, France. Talk entitled "Maternal Serum CXCL9 and CXCL10 and the Risk of Preeclampsia and/or Fetal Growth Restriction Associated with Placental Inflammation"
Year(s) Of Engagement Activity 2019
URL https://journals.sagepub.com/home/rsx
 
Description SRI 2019 - Dr Francesca Gaccioli poster presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Francesca Gaccioli was successful with her abstract submission for a poster presentation entitled "Maternal Serum CXCL9 and CXCL10 and the Risk of Preeclampsia and/or Fetal Growth Restriction Associated with Placental Inflammation.", (Abstract # 2215) at the SRI 66th Annual Scientific Meeting 12-16 March 2019 in Paris, France.
Year(s) Of Engagement Activity 2019
URL https://www.sri-online.org/meetings-calendar/2019
 
Description SRI Conference 2018 poster presentation (Dr Susanne Lager) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager - poster presentation at the Society for Reproductive Investigation 65th Annual Scientific Meeting 6-10 March, Hilton San Diego Bayfront Hotel. Session Late Breaking Poster Session, 10 March 9:30-11:30am. Authors - Susanne Lager, Ulla Sovio, D Stephen Charnock-Jones, Gordon CS Smith. Title: Spontaneous Preterm Birth is Associated with Increased Placental
Inflammation and Vascularization.
Year(s) Of Engagement Activity 2018
URL http://www.sri-online.org/meetings-calendar/2018
 
Description SRI Conference 2018 poster presentation (Dr Susanne Lager) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager - late breaking abstract accepted for poster presentation at the Society for Reproductive Investigation 65th Annual Scientific Meeting 6-10 March, San Diego, USA. Title: Spontaneous Preterm Birth is Associated with Increased Placental Inflammation and Vascularization.
Year(s) Of Engagement Activity 2018
URL http://www.abstractsonline.com/pp8/#!/4592/presentation/3881
 
Description SRI Conference 2018 poster presentation (Dr Susanne Lager) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager - poster presentation at the Society for Reproductive Investigation 65th Annual Scientific Meeting 6-10 March, Hilton San Diego Bayfront Hotel. Session Late Breaking Poster Session, 10 March 9:30-11:30am. Authors - Susanne Lager, Ulla Sovio, D Stephen Charnock-Jones, Gordon CS Smith. Title: Placental Volume Fraction of CD8+ T-Cells Are Increased in Pre-Eclampsia and Fetal Growth Restriction.
Year(s) Of Engagement Activity 2018
URL http://www.sri-online.org/meetings-calendar/2018
 
Description SRI Conference 2018 poster presentation (Dr Susanne Lager) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Susanne Lager - late breaking poster presentation at the Society for Reproductive Investigation 65th Annual Scientific Meeting 6-10 March, San Diego, USA. Title: Placental Volume Fraction of CB8 T-Cells Are Increased in Pre-Eclampsia and Fetal Growth Restriction.
Year(s) Of Engagement Activity 2018
URL http://www.abstractsonline.com/pp8/#!/4592/presentation/3892