Transplanted bone marrow cells may age faster than normal, according to a study in this week's The Lancet . The findings may explain why some bone marrow recipients develop leukemia and other blood disorders later in life, the researchers write. In the study, Dr. Robert Wynn and his colleagues from Manchester, England, compared the length of structures, called telomeres, found at the end of chromosomes in cells from 14 people who had received bone marrow transplants with those in cells taken from their marrow donors.
Telomeres shorten each time a cell divides.
As they shorten, chromosomes can become unstable increasing the risk of mutation, this may be why the rates of some cancers increase with age. When telomeres become too short, the cell dies. The length of a cell's telomeres gives an indication of how many times it has divided and can be used to make an estimate of its age. In their study, Wynn and his colleagues found that the telomeres of the cells from the marrow recipients were on average 400 bases shorter than the telomeres of cells from their donors. But it approaches 40 years in some patients.