Table 3.

Baseline and day 12 mean (±SD) platelet reactivity values in healthy subjects and patients with sickle cell disease

Measure	Time	Healthy subjects (n = 13)	Sickle cell disease (n = 13)	P value*
LTA/MPA, 5 μm ADP (%)	Baseline	80.4 ± 23.2	73.1 ± 14.4	0.376
	Day 12	29.4 ± 12.5	40.4 ± 20.5	0.143
	P value†	<0.001	0.026
LTA/MPA, 20 μm ADP (%)	Baseline	85.0 ± 15.9	73.4 ± 12.9	0.064
	Day 12	40.8 ± 15.3	50.7 ± 25.6	0.269
	P value†	<0.001	0.003
VerifyNow (PRU)	Baseline	322.5 ± 74.2	407.9 ± 39.6	0.003
	Day 12	111.5 ± 81.8	213.9 ± 72.2	0.003
	P value†	<0.001	<0.001
VerifyNow, device-reported inhibition (%)	Baseline	12.0 ± 11.0	1.0 ± 2.2	0.004
	Day 12	71.3 ± 19.7	47.8 ± 15.9	0.003
	P value†	<0.001	<0.001
VerifyNow, calculated inhibition (%)	Day 12	65.8 ± 23.4	47.8 ± 18.6	0.067
	P value†	<0.001	<0.001
MEA, 6.5 μm ADP (AU. min)	Baseline	76.5 ± 13.2	106.4 ± 27.9	0.002
	Day 12	27.0 ± 10.7	49.1 ± 24.9	0.008
	P value†	<0.001	<0.001
MEA, 20 μm ADP (AU.min)	Baseline	85.0 ± 19.0	108.1 ± 27.7	0.022
	Day 12	30.9 ± 15.7	48.0 ± 23.6	0.046
	P value†	<0.001	<0.001
Plateletworks, 20 μm ADP (%)	Baseline	91.3 ± 9.8	74.0 ± 30.0	0.061
	Day 12	37.9 ± 16.2	23.3 ± 21.2	0.081
	P value†	<0.001	0.009
VASP, flow cytometry (PRI%)	Baseline	78.91 ± 10.03	59.36 ± 23.31	0.018
	Day 12	29.03 ± 18.18	16.07 ± 13.58	0.078
	P value†	<0.001	0.002
VASP, ELISA (PRI%)	Baseline	94.70 ± 2.39	92.03 ± 5.65	0.159
	Day 12	24.26 ± 17.32	24.08 ± 12.98	0.978
	P value†	<0.001	<0.001

Abbreviations are as follows: ADP, adenosine diphosphate; AU.min, area under the aggregation curve; ELISA, enzyme-linked immunosorbent assay; LTA, light transmission aggregometry; MEA, multielectrode aggregometry; MPA, maximal platelet aggregation; PRI, platelet reactivity index; PRU, P2Y12 reaction units; SCD, sickle cell disease; and VASP, vasodilator-stimulated phosphoprotein.

^*P values for between-group comparisons are from Student's unpaired t-test.

^†P values within groups from baseline to day 12 are from Student's paired t-test.