Ex vivo expansion of hematopoietic stem and progenitor cells: Recent advances

Table 1 Comparison of the sources for hematopoietic stem cells

	Advantages	Disadvantages
Bone marrow	1 The longest history as a source of HSC	1 High stringency for HLA matching
	2 Well established procedure	2 Some complications associated with harvesting
		3 Risk of GVHD
Umbilical cord blood	1 Off-the-shelf availability	1 Delayed engraftment
	2 Reduced stringency for HLA matching	2 Lower yield
	3 Low risk of infection/transmission	3 Lack of additional immune cells
	4 Absence of donor risk
Peripheral blood	Compared to BM,	1 Extremely low level of HSC (1/100000) without “mobilization”
	1 More comfortable for donors	2 Risk of GVHD
	2 Better yield with mobilization

HSC: Hematopoietic stem cell; HLA: Human leukocyte antigen; BM: Bone marrow; GVHD: Graft-versus-host disease.