Table 1.

Distribution of stromal cells in normal/reactive bone marrow (BM) and both diagnostic and follow-up BM samples from children vs. adult patients diagnosed with BCP-ALL.

Samples	% BM Stromal Cells-From All BM Cells	% Mesenchymal Cells-From BM Stromal Cells	% Endothelial Cells-From BM Stromal Cells	% Blast Cells by FCM
Normal/Reactive BM Donors
Children (n = 10)	0.064 (0.014–0.087)	80 (71–96)	20 (4–29)	-
Adults (n = 6)	0.014 (0.005–0.037)	81 (75–90)	20(10–25)	-
p-value	0.011	0.875	0.875	-
Diagnostic BCP-ALL BM
Children (n = 129 ∆, n = 0 ♥)	0	0	0	84 (20–99)
Adults (n = 100 ∆, n = 12 ♥)	0 (0–0.44)	100 (25–100)	0 (0–75)	81 (30–97)
p-value	<0.001	NA	NA	0.293
Day +15 BCP-ALL BM
Children (n = 309 ∆, n = 247 ♥)	0.029 (0–1.57)	76 (13–99)	24 (1–87)	0.45 (0–84)
Adults (n = 41 ∆, n = 35 ♥)	0.04 (0–0.95)	76 (15–100)	24 (0–85)	1.1 (0–91)
p-value	0.541	0.802	0.802	0.087
Day +33 BCP-ALL BM
Children (n = 282 ∆, n = 266 ♥)	0.048 (0–1.85)	76 (38–98)	24 (2–62)	0.002 (0–56)
Adults (n = 66 ∆, n = 57 ♥)	0.029 (0–1.11)	73 (0–100)	27 (0–100)	0.001 (0.001–77)
p-value	0.010	0.097	0.098	0.705
Day +78 BCP-ALL BM
Children (n = 233 ∆, n = 228 ♥)	0.063 (0–1.22)	76 (40–95)	24 (5–60)	0 (0–11)
Adults (n = 44 ∆, n = 42 ♥)	0.043 (0–0.063)	76 (38–98)	24 (2–62)	0 (0–63)
p-value	0.025	0.863	0.867	<0.001

Abbreviations: BM: bone marrow; BCP-ALL: B-cell precursor acute lymphoblastic leukemia; NA: not applied; ^∆ Total number of samples analyzed; ^♥ Number of samples in which stromal cells were present.