1. Making internal biopsies redundant
Associate Professor Rupert Leong is using laser light to probe the intestinal lining, a pioneering
technique which can provide both structural and functional details of gastrointestinal diseases
ASSOCIATE PROFESSOR RUPERT LEONG
for patients. Some patients need minimal barrier. The microscope allows us to visualise
medication to reconstitute the barrier function, living tissue of the bowel and we can then
but others require the ‘big-guns’ of treatment evaluate the endoscopy in the standard fashion,
called biological agents. This concept of plus obtain functional information on the bowel
personalised medicine works well using confocal wall lining. We have already obtained good
endomicroscopy and proteomics. evidence that drugs used to treat inflammatory
bowel disease can all reverse the barrier
Have you been able to explore certain features dysfunction. In particular, biological agents are
of inflammatory bowel diseases that other the best drugs to repair the barrier breakdown of
procedures are unable to identify? the bowel lining.
Yes, the functional effect of the bowel lining – the The technology is constantly improving and we
barrier function. This is the barrier that stops have moved on to looking at other diseases that
bacteria and other organisms from entering the include detecting Barrett’s mucosa pre-cancerous
bloodstream. At present, the concept behind changes of the oesophagus and gastric intestinal
inflammatory bowel disease is that this barrier metaplasia, which may also be pre-cancerous
may be broken and leak bacterial products changes of the stomach.
into the intestinal wall, resulting in chronic
To begin, could you provide a broad outline inflammation in the bowel. Taking conventional And lastly, what have been your proudest
of your recent project and your reasons for forceps biopsies kills the cells and they no longer achievements during your work so far?
venturing into this area of research? function so you cannot evaluate the barrier
function. My research has attracted a level two (the
Confocal endomicroscopy allows endoscopists highest) clinical Career Development Fellowship
to view the cell structure of the lining of the When an intravenous contrast is introduced from the National Health and Medical Research
bowel. The main function of the bowel is to at the time of the confocal endomicroscopy Council of Australia because the research
protect the rest of the body from the bacteria procedure, the contrast leaks out of the bowel materials are novel and the topic is high in
inside the bowel ‘lumen’ – the cavity where the into the gut. This is significantly more common impact. Only five of these fellowships were
faeces reside. Using confocal endomicroscopy, in inflammatory bowel diseases than in age- awarded nationally at this level for clinical
we are now validating the characteristics of the matched controls, ie. people who do not have research when I applied. In addition, I
bowel wall barrier. This is really exciting because inflammatory bowel diseases. What we are enjoy seeing my previous trainees
this has never been seen before. With confocal noticing may be the reason why patients have and fellows doing well in their
endomicroscopy technology, we can see things inflammation in their bowels – the gut lining careers, and some have even
that conventional microscopy misses because may no longer block the entry of foreign matter followed my footsteps
we are viewing living tissue. For instance, the into the bowel wall. This could then trigger the into gastroenterology
functional effect of the bowel lining is not seen inflammation cascade that results in ulcers research.
when taking forceps biopsies, because removing forming in the inner lining of the gut. In severe
the cells from the bowel wall kills the cells and cases, the intravenous contrast floods through
they are no longer functional. In vivo in situ into the bowel very rapidly and in multiple areas.
visualisation of the intestinal lining cells gives This way we can measure the severity of the
us not only the information of their structure leakage.
and architecture, but their adequacy of barrier
function as well. What advantages have you gained by fitting
the flexible endoscope with a confocal laser
Further to this, how are you integrating microscope, and where do you go next
your dual research directions of confocal with the research?
endomicroscopy and proteomics?
Our ongoing research is to be
In combination, proteomics and confocal able to objectively measure
endomicroscopy allows us to evaluate both the the dysfunction of the
structure and the barrier function of the bowel, gastrointestinal
and this is a new way of assessing the disease tract and to see if
process. Confocal endomicroscopy can visualise medications can
and measure the severity of the breakdown in the reverse this
barrier of the bowel lining. Plasma proteomics breakdown
then measures the bacteria products that escape in the
into the bloodstream to quantitate the aftermath
of the breakdown.
In addition to the diagnosis and assessment of
the severity of bowel inflammation, I also
hope to be able to individualise treatment
64 INTERNATIONAL INNOVATION

2. ASSOCIATE PROFESSOR RUPERT LEONG
Illuminating
inflammatory
bowel disease
A new imaging technique pioneered in Australia is
revolutionising our understanding of bowel diseases
by bringing together laboratory and clinical research
to analyse the microscopic structure of the gut
ENDOSCOPY IS A medical technique coeliac disease – a genetically determined
in widespread use for the diagnosis and wheat allergy disease – can be diagnosed
treatment of bowel complaints. It consists immediately.
of a camera mounted on the end of a
flexible tube to allow direct visualisation Typically, analysis of the cellular architecture
of the internal gastrointestinal lining (the (histology) requires biopsies to be taken by
mucosa). A new technique called confocal forceps from the wall of the gastrointestinal
endomicroscopy (CEM) is a revolutionary tract. However, the forceps used in biopsies
improvement in endoscopic imaging as it often disrupt the structure of the sample as
incorporates a confocal laser microscope into well as removing the tissue from its living
the tip of the endoscope. environment, resulting in artefacts that may
lead to misdiagnosis. Furthermore, biopsies
Associate Professor Rupert Leong from The may result in false negative results from non-
University of New South Wales is pioneering representative specimens or failure to orientate
this technique. His research focuses on the tissue samples. In addition, using forceps
microscopic cellular architecture of the biopsies carries the rare risk of bleeding and
bowel wall which is invisible to conventional bowel perforation. The advantage of CEM is that
endoscopes. CEM instantly diagnoses it allows for the analysis of the gastrointestinal
neoplastic growth in the gastrointestinal mucosa in its natural living environment.
tract through the irregular arrangement, size
and shape of cells. The microscopic hair-like
PIONEERING RESEARCH
projections of the small bowel (called villi)
can be instantly recognised using CEM and In Australia, Leong has been the top contributing
research gastroenterologist for two consecutive
years at their annual national society
conference and has achieved the highest level
clinical Career Development Fellowship from
the Australian National Health and Medical
Research Council – only five such fellowships
were awarded nationally in the year of Leong’s
application. This reflects both the novelty and
impact of his research.
As an Associate Professor at The University
of New South Wales, and as Head of the
Inflammatory Bowel Diseases Services at
Concord and Bankstown Hospitals, Sydney,
Australia, Leong is ideally positioned to bring
together laboratory and clinical research.
Image of confocal endomicroscopy of the bowel show-
ing leakage of intravenous contrast into the lumen.
Previously, he has shown CEM to be as least
as accurate as forceps biopsies in the diagnosis
WWW.RESEARCHMEDIA.EU
65

3. INTELLIGENCE of coeliac disease, and has reviewed the safety When examining the mucosa of inflammatory
of the intravenous contrast agent fluorescein bowel disease patients, Leong noticed that the
PROTEOMICS AND CONFOCAL that can be used to stain cellular structures fluorescein contrast agent given intravenously
ENDOMICROSCOPY IN THE for visualisation during CEM. Recently, Leong was leaking through the gut lining and into
EVALUATION OF INFLAMMATORY has turned his expert eye towards CEM in the the lumen of the intestine. One of the most
BOWEL DISEASES diagnosis and evaluation of inflammatory bowel important functions of the mucosa is as a barrier
diseases. to separate the contents of the lumen, including
OBJECTIVES
digestive enzymes, bacteria and faecal waste,
To measure the integrity of the from the rest of the body. Therefore, a ‘leaky’
INFLAMMATORY BOWEL DISEASES
intestinal mucosal barrier. Confocal laser lining, seen to a significantly higher degree in
endomicroscopy visualises leakage across Currently, little is known of the causes of inflammatory bowel disease patients relative to
inflammatory bowel diseases, which include age-matched controls, represents a loss of this
the intestinal lining. Evaluation of intestinal
Crohn’s disease and ulcerative colitis. Both barrier function.
micro-organisms contaminating the genetic and environmental factors have been
bloodsteam is performed with a sensitive recognised. With no known causes, it follows With this discovery, Leong is focusing his
tool called proteomics. Together, they that there are no known cures for these diseases; research on using CEM to study the integrity
support the theory that the bowel wall current medication focuses on controlling the of the intestinal mucosa in the pathogenesis
barrier is broken in inflammatory bowel symptoms and disease progression. of inflammatory bowel disease: “We are now
diseases. validating the features of a ‘leaky gut’ - this is
A major symptom is the development of really exciting because it has never been seen
KEY PARTNERS ulcers in the gastrointestinal tract. Ulcers before”. He theorises that invasion of the gut
Bankstown-Lidcombe Hospital are typically the cause of bleeding from the wall by foreign matter from the intestinal lumen
bowel, severe abdominal pain, weight loss and may trigger the inflammatory cascade, resulting
Concord Repatriation General Hospital diarrhoea. In addition, patients often become in ulceration of the mucosa.
iron deficient and hence anaemic, afflicting
NSW Health them with additional symptoms such as
PROTEOMICS
University of New South Wales fatigue. In extreme cases, patients may develop
cancer or require extensive surgery to remove To explore the effects of the leaky gut, Leong is
FUNDING whole sections of the bowel. Up to three in searching for the presence of bacterial proteins
1,000 people suffer from inflammatory bowel in the blood of inflammatory bowel disease
National Health and Medical Research diseases. Unfortunately, many patients are patients. And in order to do this, he is using
Council of Australia in the formative years of their lives and the proteomics. Proteomics is the identification
debilitating impact of Crohn’s or ulcerative of the constituent proteins of a system from
CONTACT
colitis can be highly inconvenient. protein fragments known as peptides. Peptides,
Associate Professor Rupert Leong MBBS, or combinations of peptides, are unique to
MD, FRACP, AGAF Normally, inflammatory bowel diseases their parent proteins. As different organisms
Director of Endoscopy, Concord and are diagnosed by a colonoscopy to look for (and indeed different cells) are composed of
inflammation and ulcers, followed by biopsies different sets of proteins, proteomics can be
Bankstown Hospitals
for further study by pathologists. Leong instead used to detect the presence of foreign bodies.
Conjoint Associate Professor of Medicine has been using CEM not only to diagnose and If the leaky mucosa of inflammatory bowel
Bankstown Hospital evaluate inflammatory bowel diseases at disease patients is indeed allowing gut bacteria
Eldridge Road Bankstown Hospital – his instrument is the only and other foreign matter to cross the gut wall,
one in the state of New South Wales – but now then there will be higher concentrations of gut
Bankstown, NSW 2200
to also assess the barrier function of the bowel bacterial proteins in the blood of these patients
Australia
lining. From these clinical investigations, he relative to healthy individuals.
T +61 2 9767 6111 has shown that CEM is superior to biopsies and
F +61 2 9767 6767 has furthermore revealed that the lining of the Leong hopes to use the presence of these proteins
E rupertleong@unsw.edu.au gastrointestinal tract of inflammatory bowel as a measure of leakiness and to help confirm
disease patients becomes ‘leaky’. the findings of the impaired barrier function of
the bowel. By combining CEM and proteomics,
RUPERT LEONG is a consultant Senior Staff both the structure and function of the mucosa
Specialist gastroenterologist at Bankstown, DISCOVERING A ‘LEAKY’ LINING
can be evaluated, and the result of the loss of
Concord and Macquarie University Hospitals, CEM has allowed Leong to view the function bowel integrity can be measured. Reversal of the
and Associate Professor of Medicine at as well as the structure of the gut lining. abnormal changes and normalising the protein
the University of New South Wales and Biopsies disrupt the natural environment of constitutent of the blood may be an end point
Macquarie University, Sydney, Australia. His and kill the extracted cells, resulting in a loss of of treatment. He has already extended this
expertise includes interventional endoscopy function. Therefore, biopsies can only provide combined approach to other diseases such as
and management of inflammatory information on the structure of tissue. In pre-cancerous changes of Barrett’s oesophagus,
contrast, CEM visualises living tissue, providing gastric intestinal metaplasia and pre-cancerous
bowel diseases. Leong is committed to
information on both structure and function. changes of the stomach.
individualised, high-quality management,
and fostering novel research.
By combining confocal endomicroscopy and proteomics, both the
structure and function of the mucosa can be evaluated, giving a more
in-depth analysis of the pathogenesis of inflammatory bowel disease
66 INTERNATIONAL INNOVATION