A TEENAGER given a bone marrow transplant to save his life is now fighting another health battle after donor cells started attacking his own body cells.

Signs had been that 14-year-old Ethan Greenwood was making good progress after his transplant at Newcastle's Great North Children's Hospital last month but doctors have diagnosed him with GVH (Graft Versus Host Disease) - a complication his family had hoped they had avoided.

Ethan's donated cells think his own cells are the enemy and are attacking them - between one and four out of every five people having a donor transplant will develop some degree of the disease.

For some people it is a mild form but can be severe for others.

Ethan's mum Sharon Greenwood, 45, said: "Ethan has not been great over the past week.

"Unfortunately he has GVH disease when the donor cells attack his own cells and is a complication we had hoped we had avoided. His immune cells have also gone on a downward trend and are now very low and back to where they were four week ago."

But she added: "The doctors have started him on an intense course of medication to combat the GVH, early indications are looking positive so we are hoping he will soon be back on track."

Ethan, of Fieldhead Drive, Guiseley, has a life-threatening condition which is so rare it has no name.

It was attacking his stomach, pancreas, liver, spleen and both his lungs which were only working at 30 per cent capacity.

He had started having hospital tests three years ago when he was struggling to eat but checks for leukaemia, terminal cancer, Crohn's disease, tuberculosis, HIV and many others could not explain why his immune system was so damaged.

He is now being treated in a highly-sterile 8ft air-locked room while his new immune system has been growing. His family had been told only 100 days after the transplant does the risk of rejection reduce and that would be September 20.

He was referred from Leeds General Infirmary last year to see consultant immunologist Professor Andrew Cant at Newcastle, one of only two units in the country which perform transplants for immune deficiencies and autoimmune disorders.

The other is Great Ormond Street Children's Hospital in London.

His special room has its own nurse's station, a private bathroom and TV - the work of the unit is supported by a fundraising campaign called The Bubble Foundation UK at bubblefoundation.org.uk.

So far family and friends fundraising for the Bubble Foundation have made £5,000 by putting on events and donating to justgiving under the watchful eye of Ethan from his hospital room.

Earlier this month, the New Vic pub in Bolton Woods, Bradford, raised more than £600 with a fun day and Guiseley Cricket Club also made more than £800 for the Foundation with a Dads and Lads match, barbecue and raffle for a singed England team cricket bat.

Mrs Greenwood said: "We have now raised more than £5,000 for the bubble foundation which is fantastic, and there are still more events to come."

Ethan's justgiving page is at justgiving.com/Ethan-Greenwood2