'Just keep smiling': 5-year-old beats uncommon type of leukemia following rare allergy to chemo

Hillary Lofton-Mosley had planned out every detail of her dream wedding in Jamaica, down to her 2-year-old daughter, Harlow, serving as the flower girl.

But just a couple weeks before the big day in September 2022, as she was packing suitcases for the trip, she noticed Harlow had developed a cough. Her typical upbeat demeanor was off, too.

“You can feel when something’s wrong with your child,” Lofton-Mosley said. “I knew something was different about her.”

At first, Harlow’s care team thought she had a viral infection that would clear up on its own.

When the cough didn’t improve, Lofton-Mosley pushed for an X-ray. The doctor thought there was a chance Harlow had a heart murmur and said they could follow up with her care after the wedding.

After the family landed in Jamaica, Harlow became lethargic and didn’t want to play with her cousins. She was too tired to walk down the aisle; Lofton-Mosley’s mother had to carry her.

On the plane ride back with her grandmother, Harlow began having troubling coughing fits.

“My mom was like, ‘Something's not right about this child,’” Lofton-Mosley said. “As soon as I touch the soil, I'm taking her to the doctor.”

Harlow’s pediatrician recommended she see a pediatric cardiologist at University of Chicago Medicine Comer Children’s Hospital because of the suspected heart murmur. Lofton-Mosley and her now-husband, Gerald, cut their honeymoon short and flew back to their home in Northwest Indiana.

‘Harlow has cancer’

Lofton-Mosley said the day of Harlow’s first appointment at Comer Children’s in October 2022 was mostly a blur, aside from a blood test and a few words from the cardiologist.

It was the worst day of Lofton-Mosley’s life. “I remember the doctor looking at me, clasping his hands and saying, ‘Miss Lofton, there's no easy way to say this: Harlow has cancer,’” she said.

Harlow’s care team diagnosed her with T-cell acute lymphoblastic leukemia (T-ALL), a cancer of the bone marrow and blood. Leukemia can occur at any age, but it is most commonly diagnosed in children between 2 and 6 years old.

Pediatric leukemia is the most common type of childhood cancer, but T-ALL is one of the less common strains, said Gabrielle Lapping-Carr, MD, a pediatric hematologist/oncologist at Comer Children’s and one of Harlow’s doctors.

When children have leukemia, their bone marrow makes white blood cells that do not mature properly. These unhealthy cells rapidly reproduce, crowding out the healthy bone marrow cells that produce infection-fighting white blood cells, red blood cells and platelets.

“I always tell patients that almost every leukemia patient is diagnosed with something else first, whether it's a cold or a skin infection, or even a bruise,” Lapping-Carr said. “Everybody assumes their child has something else before they get a diagnosis of cancer, and that's OK.

"We have lots of wonderful therapies to take care of children with leukemia and I don’t want people to lose sleep over it having been called something else first. The important part is they did the good work to bring in their sick child to be evaluated.”

Like Harlow, many children with T-ALL present with symptoms like fatigue and anemia. Some may also have masses in their chests, along with breathing problems that resemble pneumonia.

Harlow and her mom would have to stay at Comer Children’s for the next few weeks. Harlow’s oncology team determined she had a good prognosis, and they were able to assure Lofton-Mosley that they felt confident in treating her daughter.

The family took comfort in knowing that Comer Children’s leukemia specialists offer the latest investigational therapies, as well as established treatments for all types of leukemia in children, and they do everything possible to minimize their effects on a child’s health.

After allergic reaction to chemo, remission

After the initial inpatient stay, Lofton-Mosley drove Harlow to the hospital for regular chemotherapy infusions.

But at the beginning of one of her early treatments, doctors made a frightening discovery: Harlow had an uncommon allergy to one of her chemo medications, PEG-asparaginase.

During an infusion, Harlow unexpectedly began to convulse. Her team quickly had to admit and intubate her, which broke her mother’s heart to watch.

Once they identified the chemo allergy, Harlow’s doctors switched her treatment regimen: more frequent doses of a shorter-acting version of the infusion, followed by oral chemo. Harlow completed the 28-month-long regimen in February.

On Lofton-Mosley’s 41st birthday in February, Harlow rang the bell in Comer Children’s to signify the end of her cancer treatment. Friends, family and members of her care team cheered and used bubble machines around her to help celebrate.

Lofton-Mosley said Harlow was a trooper through it all, even when taking her at-home oral chemo pills.

“Crushing up those pills was no fun,” she said. “She doesn’t like it, but she acts like she does. I don't even think adults could do that. But she does it.”

Cherishing every moment

Now 5 years old, Harlow is healthy and back to her smiling, upbeat self. She and her family enjoy cooking together and watching shows like “Family Feud.”

“I would tell other families going through this: Just keep smiling,” Lofton-Mosley said. “That's all you can do, because she smiled the whole time. And that, to me, is the biggest blessing.”

Lapping-Carr said she was always impressed by how much strength Lofton-Mosley brought to the table, which allowed Harlow to “not miss out on being a kid.”

“She was always still having fun every moment that she could,” Lapping-Carr said. “I think those of us who work with kids do so because the kids still want to have fun despite everything they are going through. That is what makes our job easier, and you were definitely able to see that with Harlow.”