Immune find may help transplants

By Ian Gunn
BBC correspondent in Vancouver

Donor and recipient blood types are normally matched

Researchers in Canada say it may be possible to reprogramme the immune system to accept tissue from people with other blood types.

The finding is significant as doctors normally have to carefully match the blood type of the donor and recipient.

Researchers at a Toronto hospital say in heart transplants in infants the immune system seems to be reprogrammed to accept different blood groups.

They say the findings could eventually help older transplant patients.

Implications

In the complex world of organ transplants, there has long been a simple rule.

Both donor and recipient must be from the same blood group.

That has meant that patients with type O blood, for example, sometimes die waiting for a heart from a type O donor.

But in the ground-breaking study in 2001, a Canadian team of researchers showed that rule does not apply to heart transplants performed in very young babies.

And now in research published in the journal Nature medicine, the same researchers say they have discovered that the immune system of those patients actually gets reprogrammed.

After the transplant, the scientists say, the young patient's immune system thinks both its own original blood type and the donor's blood type are its own.

That reprogramming, scientists say, has profound implications for transplant research, especially if it can be done in older patients.

It could mean that matching organ donors and recipients would become much simpler and that would both save lives and increase the number of organs that could be used in transplants.