Preschooler’s Energy Shines Despite GVHD Side Effects 

Harry Walker, 4, is a tiny tornado. His dad, “Big” Harry Walker, spends his days trying to keep up with his energetic son.

Little Harry hops, skips, and spins his way through the halls of St. Jude Children’s Research Hospital between appointments to treat graft-versus-host disease (GVHD), a side effect that sometimes happens after a stem cell (bone marrow) transplant. To look at this joyful child, one would never guess the health challenges Harry has faced during his young life.

“There were some tough times, but the only time — even through chemotherapy, even through the transplants—that we really saw him down was when he got sick with stomach viruses,” says Harry’s mother, Erica.

The last 2 years have been a rollercoaster for the Walker family, who live in North Carolina. Harry has received 2 stem cell (bone marrow) transplants to treat his acute myeloid leukemia (AML), a cancer of the blood.

In patients with AML, cancer cells take over the bone marrow, the soft, spongy material in the center of most bones. The bone marrow contains new blood-forming cells, which produce new blood cells. A stem cell transplant takes healthy blood-forming cells from a donor and gives them to the patient. If the transplant works correctly, the blood-forming cells from the donor replace the patient’s bone marrow and start making healthy blood cells.

Harry’s leukemia returned after the first transplant, so he had a second transplant. 

After the second transplant, tests showed that Harry’s cancer went away (remission), but he developed GVHD. In GVHD, immune cells from the donor’s bone marrow attack the patient’s cells and tissues. GVHD can affect multiple organs or organ systems. In Harry’s case, GVHD has caused skin changes and affected how his liver works.

Treatment for GVHD

Harry is getting a treatment for GVHD called extracorporeal photopheresis (ECP). This treatment is designed to stop a type of white blood cell from attacking Harry’s cells and tissues.

In ECP, white blood cells are removed from the patient’s blood. The white blood cells are exposed to ultraviolet (UV) light, which changes how the white blood cells work. The treated cells are given back to the patient. It is hoped the treated cells will not attack the patient’s cells and tissues.

Walker family keeps growing

Going through major life experiences while separated by more than 600 miles was challenging, to say the least. The Walkers’ faith helped them cope. Erica offers this advice to other parents: “Find something that you have faith in because that is literally the only way that I've made it through. And just keep hope.”

While Harry was going through treatment, his mom gave birth to 2 daughters — Haizely in 2023 and Harmony in 2024. The Walkers also have a daughter named Hayden, the oldest of their 4 children.

“It’s been a long 2 years,” says Harry’s dad. “We're hopeful that this ECP is the last little hump he needs to get over. And you can see Harry’s in great spirits. He is the life of the party for sure.”

Harry’s love of life has inspired those who have cared for him at St. Jude.

“He is such a happy child,” says Swati Naik, MD, Harry’s doctor. “Whenever I see him, he runs toward me and leaps into my arms. That’s the best part of my day — my Harry hug.”