By Sean Gorman

It sounds too good to be true — a kidney donor and transplant recipient with perfectly-matched immune systems even though they’re not identical twins.

But it’s true, and it happened in March at the VCU Hume-Lee Transplant Center. Two sisters were so perfectly matched that the transplant recipient won’t have to take medication to prevent her body from rejecting her new organ.

The extremely rare match was the result of Jessica Hardaway donating bone marrow to her older sister, Kristin Hamner, as a child. That was followed by a kidney donation 30 years later when she donated a kidney to her older sister in March.

“In a bone marrow transplant, what happens is you kind of reset the entire immune system with somebody else’s immune system,” says Dr. Dhiren Kumar, transplant nephrologist and living donor kidney transplant medical director at the Hume-Lee Transplant Center. “In essence, Kristin’s immune system became her sister’s immune system.”

The extraordinary circumstances that led to their perfect match are so uncommon, it would be a stretch to suggest a prior bone marrow transplant is the answer for everyone looking for a kidney their immune system won’t reject. Still, the sisters’ story raises intriguing questions about what this means for the future of transplant care.

Some transplant centers undertake bone marrow transplants prior to a kidney transplant in order achieve the type of result seen in Kristin’s case, Kumar notes.

“Research is being done on this approach,” Kumar says. “Is it mainstream yet? No, we’re still learning more and more, but the fact that this happened so perfectly for all parties involved is quite remarkable.”

A strong bond

Kristin and Jessica are not identical twins — they were born 18 months apart. But their bond is so strong, they might as well be. “We’re basically like twins,” Kristin says. “We’re joined at the hip. We think we’re much closer than most siblings.”

Although Kristin won her fight against childhood cancer, her kidney function hasn’t done as well. She’s known for years that at some point she would probably need a new kidney.

When doctors at VCU Hume-Lee Transplant Center confirmed in April 2020 that it was time for the transplant, Kristin called Jessica and told her she needed a kidney donor.

“I’m like, ‘You’re going to do it right?’” Kristin recalls asking her sister in jest.

While she didn’t want to put her sister on the spot, the question was logical That long-ago bone marrow donation from Jessica was key to helping Kristin recover from her cancer.

Kristin, now 35, was diagnosed at age 4 with neuroblastoma, a childhood cancer that forms tumors in developing nerve cells. It’s rare, with only 700 new cases diagnosed each year. The tumors most commonly reside in and around the adrenal glands, which sit atop the kidneys.

Kristin underwent full-body radiation and chemotherapy for a year. But the battle against the cancer took its toll, destroying Kristin’s bone marrow, a vital part of the immune system.

Kristin needed a bone marrow donor. Jessica, then just 3 years old, provided her own marrow during a transplant procedure at VCU Massey Cancer Center.

Kristin, of Dinwiddie County, still remembers how her sister spent the night in the same room with her following the transplant. “It was just comforting to have her nearby,” she says.

Another selfless gift

Jessica took the big step again, contacting Hume-Lee directly to see if she could donate one of her kidneys.  

Jessica, of Blackstone, underwent blood work, a CT scan, chest X-rays and other tests. There was one hurdle: Jessica’s body mass index was too high to be a donor. She’d have to lose 50 pounds.

“Kristin said ‘No, I’m not going to put you through that,’” Jessica recalls. “I told her I was doing it and going on a crash diet and working out, and that we were going to get this thing done. I said, ‘You’re going to get healthy and feeling good soon.’”

And that’s exactly what she did. With a home gym and the determination to help her sister, Jessica lost the weight in six months.

Still, there was another question lingering in Jessica’s mind. As determined as she was to help her sister, she was also a single mother with two daughters ages 7 and 14. She prayed, and Jessica says the guidance she received solidified her decision to donate.

It was all just in time. Kristin began dialysis two months before the transplant. She was so fatigued she could barely get out of bed. She eventually stopped urinating completely. By the time she had her transplant, her kidneys weren’t functioning at all.

A rare perfect match

Earlier this year, the sisters got the news. Not only were they a good match, they were a perfect match — the type of extremely rare match typically seen only in identical twins.

“Our blood is the same, our bone marrow, our antibodies. All of it is the same,” Jessica says. “I was completely speechless. My heart started beating really fast.”

Being a perfect match meant that after the kidney transplant, Kristin wouldn’t need medication to prevent her body from rejecting her new organ. 

“This is really the Holy Grail of transplant care,” Kumar said.

On March 1, 2021, about a year after learning Kristin needed a new kidney, the sisters underwent the living donor transplant at Hume-Lee. It was one of many procedures performed each year at the growing transplant center. In 2020, Hume-Lee performed 459 transplants of kidneys, livers, hearts and pancreases amid the COVID-19 pandemic. It was a record year that beat the previous record in 2019 of 434 organ transplants.

Following their surgeries, the sisters recovered in separate rooms before being given the OK to visit each other. “It was a good feeling to see her,” Kristin says. “Even though everybody was telling me she was OK, I just wanted to see her.”

Excellent outlook

The prognosis is excellent for both sisters. Tests show Kristin’s new kidney is functioning normally and her energy has improved.

Jessica says she would do it all over again. “It’s a gift that I was given,” she says of the healthy kidney she donated. “It means the world to me that Kristin doesn’t have to keep going through and suffer on dialysis.”

Kristin knows the transplants mean a healthier life and more quality time with her sister.

“I knew she was going to do it, but I never wanted to pressure her in case she changed her mind,” Kristin says. “I told her numerous times, ‘If you want to back out, I totally understand. No hard feelings.’ But she never did. It’s a wonderful feeling.”

You can donate, too

Do you know someone who needs a kidney? You can donate, too. Learn how you can be a living donor.