How old is too old? In vivo engraftment of human peripheral blood stem cells cryopreserved for up to 18 years - implications for clinical transplantation and stability programs

Table 1 Cryopreserved peripheral blood stem cells unit characteristics

PBSC unit	Unit characteristics			Pre-freeze characteristics		Post-thaw characteristics			Colony forming ability
	Donor age (yr)	Disease	Cryopreser-vation (yr)	TNC × 103/µL	%CD34	TNC × 103/µL	%TNC Recovery	%Viability	BFU-E/105	CFU-GM/106
A	25	GLIO	18.1	110	0.2	121	110	84	2	2
B	58	CML	17.7	120	0.5	111	103	86	6	10
C	46	MM	13.6	120	3.9	116	81	68	++	++
D	24	NHL	14.6	116	3.8	110	68	67	++	++
E	52	MM	17.9	127	0.2	164	90	86	0.3	0
F	66	MM	17	102	0.5	145	95	34	0	0
G	54	MM	18.3	134	0.5	114	79	81	4	6
H	52	MM	17.9	120	0.2	150	90	70	9	6
I	47	MM	17.2	114	1.5	120	80	62	0.3	0
J	47	MM	17.1	114	1.5	124	83	49	++	++

TNC: Total nucleated cells; BFU: Burst forming units; PBSC: Peripheral blood stem cells; CFU: Colony forming units; GLIO: Glioblastoma multiforme; CML: Chronic myelogenous leukemia; MM: Multiple myeloma; NHL: Non-Hodgkin's lymphoma; ++: Overgrowth too numerous to count.

Table 2 Post-CD34 selection characteristics and engraftment data

PBSC unit	Cryopreser-vation (yr)	Post-CD34 selection characteristics					Mouse bone marrow engraftment
		TNC × 103/µL	%Viability	%Purity	BFU-E/105	CFU-GM/106	Mean %CD45	Mean %CD19	Mean %CD3	Mean %CD33
A	18.1	0.3	96	95	19	56	43.4	14.8	1.1	12.6
B	17.7	0.3	94	93	54	85	63.6	20.8	0.4	13.1
C	13.6	2.5	96	98	++	++	10.3	2.8	1	5.6
D	14.6	2.4	95	98	++	++	20.3	6.8	0.5	7.8

TNC: Total nucleated cells; PBSC: Peripheral blood stem cells; BFU: Burst forming units; CFU: Colony forming units; ++: Overgrowth too numerous to count.