Sources of stem cells used to treat bone marrow failure vary around the world, with bone marrow harvest more commonly used in areas with more resources. Peripheral blood stem cells (PBSCs) are more commonly used in regions with limited resources, according to a recent publication in JAMA (doi:10.1001/jama.2015.13706).
The use of PBSCs and bone marrow as stem cell sources for transplant of hematopoietic stem cells in patients with bone marrow failure was investigated by Ayami Yoshimi, MD, PhD, of the University of Freiburg, Germany, and colleagues. They also analyzed factors associated with the use of each stem cell source.
Prior to the 1990s, bone marrow was the only stem cell source available, then PBSC and cord blood began to be used for hematopoietic stem cell transplantation (HSCT) in patients with bone marrow failure. PBSCs are now the major stem cell source. They offer faster engraftment and ease of collection; however, in patients with nonmalignant disorders, incidence of graft-vs-host disease is higher and survival rates are lower. Bone marrow is currently recommended for HSCT in patients with bone marrow failure.
For this study, the researchers used data from retrospective HSCT surveys by the Worldwide Network for Blood and Marrow Transplantation, the organization that funded this study. International and regional organizations collect the numbers of transplants annually by disease, donor type, and stem cell source from World Health Organization (WHO) member states known to perform HSCT. Most data are from transplant registries.
Of the 194 WHO member states, 84 perform HSCT. Among the 114 217 HSCTs reported, 3282 allogeneic HSCTs were performed for bone marrow failure, and the stem cells sources for these were bone marrow (54%), PBSC (41%), and cord blood (5%).
Bone marrow was used most commonly in the Americas (75%) and in Europe (60%), but not in the Eastern Mediterranean region and Africa (46%) or in the Asia Pacific region (41%; excluding Japan [19%]).
Bone marrow use was higher in high-income countries (64%) than in low- (20%) or middle-income (50%) countries.
“National and international transplant organizations and authorities should foster regional-accredited bone marrow harvest centers for patients with nonmalignant disorders and provide resources to establish such infrastructures,” stated the authors. “Unrelated donor registries should provide information on the necessity of bone marrow donation for patients with bone marrow failure.”