Clinical Case Report: Haploidentical Stem Cell Transplantation

Every year in the United States, 8,000 bone marrow transplants are performed in an effort to treat acute leukemias and other conditions. Of this total, 3,500 transplants are from an unrelated donor, while 2,000 are from a related donor. Another 2,000 are haploidentical stem cell transplants. A haploidentical (haplo) transplant is a type of allogeneic transplant using cells from a half-matched donor.  

 Haplo transplants have increased exponentially since 2010. They now account for 25 percent of all allogeneic bone marrow transplants. This has been particularly beneficial for patients who do not have a suitable donor. The odds of finding a suitable match through the National Marrow Donor Program are poor for African-Americans and other ethnic groups. Most donors on the registry are Caucasian. For Caucasians, there is a 75 percent chance of finding a match; for African-Americans, the chances drop to 30 percent.  

 In the past, haplo transplants were not performed because a 50-percent match carried an excess risk of death related to graft vs. host disease. Today, novel anti-rejection regimens, aggressive infection prevention and novel relapse prevention allow us to offer curative therapies to patients who otherwise would be excluded. Below we present a case report of a successful haploidentical stem cell transplant.  

The patient is a 39-year-old white male with no significant medical history. While serving in Afghanistan for the U.S. military, he sought medical attention for nosebleeds and excessive fatigue. The medical team’s assessment revealed a markedly enlarged spleen, and lab studies showed a high white blood cell count. A diagnosis of chronic myeloid leukemia (CML) was established, and he was transferred home to the U.S. 

The patient was referred to Robert Brian Berryman, M.D., a medical oncologist and stem cell transplant specialist at Texas Oncology and on the medical staff at Baylor University Medical Center in Dallas, Texas, who confirmed the leukemia diagnosis. The patient was placed on a novel targeted therapy known as a tyrosine kinase inhibitor (TKI). TKIs target the Philadelphia chromosome, which encodes the protein BCR-ABL, the underlying mutation in CML. 

Although several generations of TKIs were utilized, none effectively controlled his disease. Ultimately, the patient’s leukemia progressed and evolved into a more advanced form of CML associated with another hematolymphoid malignancy: myelodysplastic syndrome. As a result, Dr. Berryman recommended proceeding with an allogeneic stem cell transplant. Adopted at birth, the patient was not aware of any siblings. A search of the National Marrow Donor Program revealed no suitable donors.  

Plans were made to proceed with a haploidentical stem cell transplant, using cells from his birth mother. 

The peripheral blood stem cell transplant was performed on July 4, 2013, resulting in a continuous, complete remission. Eight years later, the patient watched his son graduate high school, walked his daughter down the aisle, and celebrated his 28th anniversary with his wife. On July 4, 2023, the patient marked his personal Independence Day, 10 years cancer free. 

“In this case, the patient and I were able to work together to determine the best course of action to treat his CML,” said Dr. Berryman. “When his cancer wasn’t responding to traditional treatment, we turned to a stem cell transplant with his birth mother as his only match. The emergence of haploidentical-related donors has greatly increased the likelihood of finding a donor for virtually every patient who needs a transplant.” 

Established in 1983, the Blood and Marrow Transplant Program at Baylor University Medical Center at Dallas holds 40 years of innovation and inspiration. The physician-researchers on the medical staff have led and collaborated with other major transplant centers in clinical trials focusing on haploidentical transplants. These trials conducted at Baylor Dallas have established haploidentical transplant as the standard of care. 

If you have any questions or would like more information about haploidentical transplants or to refer a patient, call 214.370.1816.