Great news for Jonathan Pitre today.

His mother, Tina Boileau, says test results today show his white blood cells remain 100 per cent engrafted.

This follows a stem cell transplant two months ago at the University of Minnesota Masonic Children’s Hospital, which is pioneering such transplants.

In a Facebook post, Boileau also says his skin is now showing encouraging signs of healing.

The 17 year old Pitre suffers from a very rare disease that makes his skin extremely fragile and prone to painful blistering.

Jonathan suffered a setback earlier this month when he came down with an infection.

But Boileau says her son has been infection-free for three days now - a good sign.