Give us the tools and we will finish the job
-Winston Churchill
An alliance of clinicians, academics, research nurses, funders, coordinators, programmers
and, most importantly, patients has come together in the UK to deliver a powerful
new platform to accelerate Crohn’s and Colitis research—the inflammatory bowel disease
(IBD) BioResource. As part of the National Institute for Health Research (NIHR) BioResource
for translational research, 25 000 patients in over 90 hospitals UK-wide have signed
up since we launched in January 2016 (figure 1). All have detailed phenotypes databased
including Montreal classification,1 treatment response history (updated annually),
surgical history and comorbidities (see IBD BioResource panel descriptive, Clinical
data collection sheet and Health and Lifestyle questionnaire). Serum, plasma and DNA
samples are banked; and genome-wide genetic profiling undertaken. Participants’ data
and samples can be studied, and they themselves surveyed or recalled for resampling
or downstream studies (see figure 2). Critically, such studies can be led by any UK
or overseas investigator whether from the worlds of clinical research, pharmacovigilance,
science or industry.
Figure 1
IBD BioResource recruitment in over 90 hospitals in the UK. IBD, inflammatory bowel
disease.
Figure 2
How the IBD BioResource works. HES, Hospital Episode Statistics; HSCN, Health Social
Care Network; IBD, inflammatory bowel disease; NHS, National Health Service.
What is the IBD BioResource for
A key motivation is to leverage recent genetics advances, and by understanding the
functional impact of IBD-associated gene variants accelerate translation of the new
knowledge for clinical benefit. Beyond this, it is increasingly evident that the IBD
BioResource can facilitate a wide spectrum of research. This might include anything
from mining existing data or samples or surveying the cohort regarding outcomes of
newly licensed treatments, to pharmacogenetic research. It could also be used to expedite
recruitment to intervention studies, including experimental medicine and conventional
drug trials.
Gene discovery in Crohn’s disease and ulcerative colitis has placed these conditions
at the forefront of the field of common disease genetics. As the UK IBD Genetics Consortium
we have, through national and international collaboration, helped deliver a number
of landmark studies in IBD.2–14 More than 240 confirmed IBD susceptibility loci have
been identified to date. New druggable pathways continue to be identified and new
pathogenic insights continue to accrue,4 particularly from those loci where the causal
variants have been identified and functionally characterised. Examples of the latter
include the association between IBD and the R381Q variant in the interleukin 23 receptor
and between CD and the T300A variant in the autophagy gene ATG16L1.15–17
For most IBD risk loci, however, the causal genes and causal variants await identification.
There are instances of hard-fought progress, with dissection of individual loci allowing
new genes to be characterised and new biological insights gained18 19; and using innovative
genetic ‘fine mapping’ techniques it has been possible to refine ~20% of risk loci
to a single variant.2 However, functional characterisation of the latter is awaited,
and is made all the more challenging by the fact that most are non-coding (regulatory).
Furthermore, more than 50% map to genomic regions lacking homology with any known
functional motif. The prize may be new biological insight not just about IBD pathogenesis
but potentially also new understanding of the regulation of gene transcription, but
no number of DNA samples can deliver this. Without recourse to mouse models or genetically
manipulated cell lines, with all their problems, investigators will be able to use
the IBD BioResource to access and resample cohorts of patients homozygous for risk
and wild-type alleles at any locus. Already, despite only having recently reached
maturity, such ‘stage 2’ recall-by-genotype studies are in progress. These are interrogating
the functional impact of cytokine polymorphisms, non-coding RNA’s and HLA variants
implicated in our genome wide association studies (GWAS), to better understand how
these contribute to IBD pathogenesis and to specific subphenotypes.
Critical to the success of the IBD BioResource will be the willingness of patients
to participate in annual surveys (to gather long term data re treatment outcomes etc)
and stage 2 studies. It is early to be drawing conclusions, but in stage 2 studies
to date 30%–60% of eligible participants have agreed to help. Maintaining engagement
with patients and potential stage 2 users is clearly a key role of the team of four
IBD BioResource coordinators and one data manager. As well as running the annual surveys,
they maintain the website (www.ibdbioresource.nihr.ac.uk), circulate newsletters and
promote activities through social media (Twitter and LinkedIn). Over the next 5 years,
it is anticipated that longitudinal data from surveys will be substantially augmented
by access to NHS digital and potential collaborations with the IBD Registry and Health
Data Research UK, to minimise the risk of participants being lost to follow-up.
In addition to its recall/resample functionality, the IBD BioResource will also be
used as the substrate for a new suite of genetics analyses. There is still more mileage
in GWAS for risk variants: as the IBD dataset expands so the number of loci detected
will increase in linear proportion, and new insights gained.20 Beyond GWAS increasing
attention is turning to exome and whole genome sequencing, particularly to ascertain
low frequency risk variants of potentially greater effect size than are typically
identified by GWAS.3 These may contribute to the ‘missing heritability’ of IBD and
other common diseases.21 Two limiting factors to date have been sequencing costs and
the need for very large sample sizes to detect rare variant associations with statistical
confidence. Both are becoming tractable. All IBD BioResource participants will undergo
50x exome sequencing or 20x genome sequencing and the data will be meta-analysed with
other datasets in the international IBD genetics consortium in well powered studies;
and the results made available to the research community.
Translational aspects
As well as identifying susceptibility genes, there is increasing interest in identifying
biomarkers for clinically relevant outcomes such as prognosis and treatment response,
the aim being to deliver on the promise of personalised medicine. This requires detailed
phenotypes on large sample sets—something the IBD BioResource has, with 95% completion
of core data fields on the first 24 000 participants. Lee et al previously used GWAS
to identify loci associated with Crohn’s disease prognosis22; and blood monocytes
from genotype-selected NIHR BioResource subjects to interrogate the function of a
FOXO3 polymorphism.23 The expanding IBD BioResource dataset should identify more markers
associated with disease course and enable development of progressively more accurate
‘polygenic scores’ for prognosis. The latter use the power of genome-wide data (rather
than just genome-wide significant hits), potentially combined with environmental modifyers
such as smoking, to substantially improve predictive accuracy.24 This could be used
at the time of IBD diagnosis to identify individuals destined for a complex disease
course with multiple flares, perhaps warranting early and aggressive therapy.
Regarding treatment outcomes, pharmacogenetic analyses have recently identified a
number of clinically important associations. Thus, NUDT15 polymorphisms are associated
with thiopurine-induced leucopenia both in Asians and Europeans25 26; and human leukocyte
antigen (HLA) DRB1*0701 is associated with risk of thiopurine pancreatitis.27 Other
work lead by Tariq Ahmad in Exeter, including samples from the IBD BioResource, has
identified strong association between HLA DQA1-05 (found in 40% of people of European
origin) and immunogenicity to anti tumour necrosis factor (TNF) therapy.28 Studies
to demonstrate the utility of testing for these in the IBD clinic is a near-term objective
for IBD BioResource investigators.
Future pharmacogenetic studies will also benefit from the scale of the IBD BioResource.
By recruiting from hospital clinics, it is biased towards more severely affected patients.
Thus >13 000 have been treated with thiopurines and >9000 with anti-TNF therapy, all
with detailed treatment outcomes recorded. Through the IBD BioResource, all participants
can be recontacted or recalled if more detailed information or more samples are required.
Even relatively recently introduced therapies are strongly represented, for example,
over 1400 participants have received vedolizumab—and through an annual ‘treatment
update’ survey, we expect to see this number climbing rapidly. We thus have a clear
opportunity to better understand how these treatments are being used in routine practice,
and for further pharmacogenetic analyses, for example, of treatment response. There
may also be a role for the IBD BioResource in pharmacovigilance for new therapies.
Supporting intervention studies and drug trials
Can the IBD BioResource directly support intervention studies, including drug trials?
We believe so. Later this year, it will be used to recruit to the IBD BOOST study,
surveying 12 000 patients and then recruiting 1180 with self-reported symptoms of
fatigue, pain and/or urgency for different interventions. There is also potential
utility for drug trials recruitment. There is widespread recognition that drug development
takes too long, is too costly and potentially high risk.29 With the recent expansion
of licensed IBD therapies industry may see the cost of developing a new drug, particularly
one that ends up as fourth or fifth line therapy, as too great—and might shelve some
of the potentially valuable new treatments.30 Different strategies are required, potentially
including experimental and precision medicine to investigate subgroups of patients
who have distinct pathogenic pathways and in whom drugs which target those pathways
may demonstrate high efficacy (hence warranting earlier use in such biomarker-defined
subsets). The IBD BioResource, with its detailed genome-wide data, is ideally positioned
to support such studies.
At a more general level, the IBD BioResource is well placed to accelerate recruitment
to conventional phase 3 studies—widely regarded as a major bottle-neck in drug development.
This should be of great interest to the pharma industry and clinical research organisations.
Potential participants meeting inclusion criteria for a particular study (identified
from the IBD BioResource database of phenotypes and drug histories) and under a trial
site hospital can be provided with trial details and notified that if their IBD is
flaring and they are interested they should contact the research nurse at their site.
Many patients are only too willing to participate in research but a major block is
giving them the opportunity.31 Inherent to the problem is that most drug trial recruitment
happens in clinic, but requires the clinician meeting the patient in flare to know
about the study, be aware of inclusion criteria and to match these up to the patient
in front of them. This presupposes an alignment of knowledge, time and motivation
in busy clinicians, and all too often one or more of these is lacking. Having a large
cohort of research-engaged IBD BioResource participants who have consented to screening
of their medical records and can be contacted directly regarding research should help
circumvent this bottleneck.
The future
A key goal over the next 5 years is to recruit an inception cohort of 1000 individuals
newly diagnosed with IBD who will undergo more detailed sampling (including stool,
biopsy tissue and whole blood for RNA—unconfounded by the effects of drug treatment)
and longitudinal follow-up. In due course, this will facilitate and expand existing
research into the determinants, predictors and biomarkers of disease course and treatment
response.32 33
The IBD BioResource has more than 90 hospitals participating UK-wide, and is now recruiting
at ~1000 patients per month (figure 1). With 25 000 highly characterised patients
already signed up, it is very definitely ‘open for business’ and now able to support
and expedite a wide range of studies. What began as a resource to enable post-GWAS
studies has become a wider multidimensional platform ready for use by the global IBD
research community. Its job is to accelerate IBD research across all domains, improve
treatments and outcomes, and perhaps one day ‘finish the job’ by achieving a cure.
We are keen to see this tool used!
To apply to use the IBD BioResource please visit
https://BioResource.nihr.ac.uk/researchers/researchers/application-process/
Enquiries re its use to ibd@bioresource.nihr.ac.uk