Table 4.

Summary of Multidrug Resistance Data

Features	MDR+ (n = 63)*	MDR− (n = 28)
Shift†
Median	62	24‡
Range	10–99	1–98
PSC§
Median	86	16‡
Range	40–100	0–31
Cyclosporine§
Median	88	8‡
Range	17–100	0–33
MRK-16‖
Median	65	18‡
Range	2–99	1–97
KS/D¶
Median	0.74	0.40‡
Range	0.07–9.8	0.05–9.5
MESF#
Median	6,312	3,580**
Range	1,625–20,007	491–12,612

Abbreviations: MDR, multidrug resistance; PSC, valspodar; KS/D, Kolmogorov-Smirnov Statistics; MESF, molecules of equivalent soluble fluorochrome; P-gp, P170-glycoprotein.

^*≥40% in vitro rhodamine efflux from CD34+ blast cells (see Methods).

^†Rhodamine fluorescence channel shift, reflecting cellular rhodamine efflux, from baseline (maximal dye uptake and retention) that occurred during a 1-hour incubation of cells at 37°C (to induce dye efflux), expressed as percentage of maximal dye retention.

^‡P = .001.

^§Percentage of inhibition of in vitro rhodamine efflux from blast cells in the presence of these agents.

^‖Percentage of blast cells immuno-stained with anti-P-gp antibody MRK-16.

^¶Binding of MRK-16 to blast cells relative to background using Kolmogorov-Smirnov statistics, whereby the generated D value reflects the difference between the two binding curves.

^#MESF (MRK-16 immuno-staining), an indicator of P-gp protein density in the cellular membrane of blast cells.

^**P = .006.