New treatments for insulin disease related to diabetes
28 March 2011
New treatments for a rare
and potentially lethal childhood disease that is the clinical opposite
of diabetes mellitus has been discovered by a European research team.
Congenital hyperinsulinism (CHI) is a condition where the body’s
pancreas produces too much insulin – rather than too little as in
diabetes – so understanding the disease has led to breakthroughs in
diabetes treatment.
The study was led by the University of Manchester and carried out
at the two referral centres for hyperinsulinism in the UK, the Royal
Manchester Children’s Hospital and Great Ormond Street Hospital,
London. It also involved the University of Exeter, Antwerp
University Hospital in Belgium, and the Université Pierre et Marie Curie
and the Hôpital Necker Enfants Malades in France. The study
was published in the journal Diabetes on 16 March 2011.
“In healthy insulin-producing cells of the pancreas, a small
group of proteins act as switches and regulate how much insulin is
released,” said Dr Karen Cosgrove, who led the research with
Professor Mark Dunne in the University of Manchester’s Faculty of Life Sciences.
"When these proteins fail to function the cells can either
release too little insulin — resulting in diabetes mellitus, or too
much insulin — leading to congenital hyperinsulinism."
She continued: "CHI causes dangerously low blood sugar levels
which can lead to convulsions and brain damage if not treated
promptly. It is a complex condition caused by gene defects that keep
the insulin-producing cells switched on when they should be switched
off.
"Our group was the first to show how these gene defects led to
uncontrolled insulin release in patients a number of years ago. Now
we have taken the cells from patients following surgery and proven
that, in some cases, it is possible to correct defects in the rogue
cells."
Current drug treatments for CHI often fail in the most severe
forms of the disease and the patient has to have some, or most, of
their pancreas removed. The Manchester researchers discovered that
treating cells under specially modified conditions helped to recover
the function of the internal switches that control insulin release.
Through these experiments the team have provided the first evidence
that the outcomes of gene defects can be reversed in human
insulin-producing cells.
One of the drugs used in their studies is currently in clinical
trials to treat patients with cystic fibrosis but has not been
tested in patients with CHI. The team hope that their findings will
pave the way for new or similar drugs to be used in clinical trials
for hyperinsulinism.
“Although our results are really encouraging this is not a magic
bullet for the treatment of this devastating condition, but it does
offer real hope that in the future we may be able to use new drugs
which can reverse the cellular defects,” added Dr Cosgrove.
The clinical service at Royal Manchester Children’s Hospital now
includes state-of-the-art facilities for imaging the pancreas to
detect hyperinsulinism. The clinical and academic teams work closely
together within NorCHI (Northern Congenital Hyperinsulinism in
Infancy service) to learn more about causes and treatments for this
disease.