Donor Protein Boosts Survival in Pediatric Bone Marrow Transplants

Pediatric bone marrow transplant patients appear to do much better when the donor's genotype includes a specific natural killer cell protein.

According to Wing Leung, M.D., PhD, of St. Jude Children's Research Hospital and colleagues, pediatric patients receiving an allogeneic hematopoietic stem cell transplantation demonstrated an improved survival of 60 percent and a decrease in disease progression of 62 percent when the donor's cells include the so-called KIR2DL1-R245 polymorphism.

Hope for Transplant Patients

Perhaps the most impressive aspect of this study is that many factors, including reason for transplantation, treatment history and degree of completeness of the HLA match, did not appear to make a difference. In other words, these factors played no part in whether or not the patient benefited from the NK cell protein.

The study, appearing online in the Journal of Clinical Oncology, puts added evidence behind the growing belief that NK cells with KIR2DL1 possess an increased ability to fight cancer cells.

Said Leung:

This approach should dramatically improve the outcome of patients undergoing bone marrow transplantation, regardless of their age or underlying condition. NK cells also play an important role in autoimmune disorders, chronic infections, and other conditions, so these results will likely have an impact beyond cancer.

This was a retrospective study of 313 patients who had an allogeneic transplant at St. Jude between 2000 and 2010. The investigators performed allotyping on DNA samples from the donors.

The patients had a median age of 9.9 years at transplant.

Hematologic malignancies were the reason for transplant in 231 cases. Solid tumors accounted for 25 cases, and "nonmalignant conditions" accounted for the remaining 57.

Source: JCO