DURHAM, N.C. — In January, WRAL had the story of 4-year-old Olivia Medici of Oregon. She came to Duke Hospital for a stem cell transplant. She is now out of the hospital, but not quite out of the woods.

Last summer, Mark and Annalee Medici of Portland learned their daughter has a rare form of MPS or mucopolysaccharidosis. She lacks the enzymes to digest complex sugars.

The only life-saving hope they found was at Duke with a stem cell transplant, from a donor's umbilical cord blood. She is only the 15th patient in the world with her form of MPS to have the procedure.

Fifty-six days later, the transplanted cells are taking over.

"She has completely engrafted, and all the cells that are in there are donor cells. That's the best news that you can give to the family right now," said Dr. Vinod Prasad, of the Duke pediatric, blood and bone marrow unit.

The other good news is Olivia can leave.

"There's a little bit of sadness when you leave. You get that bittersweet feeling of, 'You're the lucky one who's leaving with your child walking out,'" said Annalee Medici.

The family now lives in a rented Durham home. More tests will track whether the donor cells will produce the enzymes Olivia lacks. Meanwhile, her immune system is weak, so the whole family will live in relative isolation.

"She can't go to a mall or a grocery store or restaurants," said Mark Medici.

The transplant may save Olivia's life, but it may or may not improve her mental or physical development. Still, so much has gone so well so far.

"Really since the day we landed until right now, we've received nothing but good news, and there's really nothing to stop us to think," Mark said. "There's nothing but optimism in our future."

If all continues to go well for the Medici family, they may be able to take Olivia back home to Oregon by May.