Longer white blood cells telomere length (a structure at the end of a chromosome) was associated with increased overall survival at 5 years among patients with severe aplastic anemia who received stem cell transplant from an unrelated donor reports a recent study.
Shahinaz M. Gadalla, M.D., Ph.D., of the National Cancer Institute, National Institutes of Health, Rockville, M.D. and colleagues studied the overall survival rate of patients with severe aplastic anemia who received stem cell transplant from an unrelated donor.
Telomeres protect chromosome ends and are essential for maintaining chromosomal stability. Telomere length is a biological marker for cellular aging and the capacity to replicate. Defects in telomere biology is one of the cause for aplastic anemia, a blood disorder where the bone marrow fails to make new blood cells.
Allogeneic hematopoietic cell transplantation (HCT) is recommended as initial therapy for young patients with acquired severe aplastic anemia when a matched sibling donor is available.
The association between recipient and donor pre-transplant leukocyte telomere length with outcomes after unrelated donor allogeneic HCT for 330 patients with severe aplastic anemia was evaluated.
Patients who underwent HCT between 1989 and 2007 in 84 centers were followed up. Based on the leukocyte telomere length tertiles in the donors, leukocyte telomere length for both recipient and donor analyses was categorized as long and short.
The researchers found that longer donor leukocyte telomere length had 5-year overall survival of 56 percent compared to 40 percent in the short donor leukocyte telomere length group.
After adjusting for donor age and clinical factors associated with survival following HCT in severe aplastic anemia, the risk of post-HCT all-cause mortality remained approximately 40 percent lower in patients receiving HCT from donors with long verses short leukocyte telomere length.