Scientists have developed a new way to treat liver failure by
dampening the immune response using stem cells taken from the bone
marrow.
Therapy to slow down liver damage
So far the technique has only been tested in animals, but if it works in humans it could help save lives.
Potentially a patient could be kept alive longer until a
donor organ is found - and the liver would be given the maximum chance
to repair itself.
The Massachusetts General Hospital work features in the journal PLOS One.
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This development could potentially reduce the number of donor organs used in urgent transplant procedures
 Professor Mark Thursz
British Liver Trust |
The liver is one of the few major organs that is able to regenerate itself.
However, the organ cannot cope with the extensive damage
inflicted by diseases like chronic hepatitis, or excessive long-term
alcohol consumption.
At present, the only treatment for severe "end-stage"
damage is a transplant - but donor organs are limited, and recipients
must rely on powerful drugs to suppress their immune response.
Key cells
External liver assist devices have successfully
supported some patients, but such machines require a supply of
preferably human liver cells, which have been difficult to acquire.
The US researchers used mesenchymal stem cells (MSCs) -
cells from the bone marrow that develop into tissues supporting blood
cell development in the marrow cavity.
Previous research has shown that MSCs are able to
inhibit several immune system activities, apparently by putting a brake
on the movement of immune cells to areas of damage.
A supply of MSCs can be extracted from a patient's own marrow and expanded to levels that could be therapeutically useful.
The researchers tested several ways of using the cells to treat rats with liver failure.
Simply transplanting MSCs into the animals' livers was not effective.
However, two methods of delivering molecules secreted by
the cells lessened inflammation within the liver and halted cell death.
Cycling the blood of rats with liver failure through an
external bioreactor containing MSCs also greatly reduced signs of liver
failure in the animals, and boosted survival rates from 14% to 71%.
Researcher Biju Parekkadan said in theory a patient
could be injected with a drug containing MSC-derived molecules to try
to halt cell damage, and allow the organ to regenerate.
If that was not successful, or the damage was too
extensive, then a device similar to the bioreactor could be considered
to buy extra time before a transplant.
The British Liver Trust warned the research was still at an early stage.
But Professor Mark Thursz, of St Mary's Hospital, London
and spokesperson for the trust, said: "A long standing goal in
hepatology is the suppression of liver cell death until regeneration
could occur.
"This development could potentially reduce the number of
donor organs used in urgent transplant procedures thereby increasing
the number available for the growing number of patients on routine
waiting lists."
