TABLE 8.

Monocyte CD4 expression levels (as a function of Ficoll-Paque isolation^a) before and after overnight culture in a whole-blood or RPMI-FBS environment

Isolation no.	Monocyte CD4 expression (mean channel no.) in:
	Whole blood (baseline)		Overnight cultures
			Whole-blood cultures		PBMC cultures in RPMI-FBS
	Autob	CD4c	Auto	CD4	Auto	CD4
29	0.427	4.63	0.253	4.93	0.256	0.269
30	0.315	4.51	0.266	4.02	0.234	0.362
31	0.284	4.49	0.233	1.82	0.249	0.264
32	0.298	5.09	0.275	1.98	0.201	0.645
Meand ± SEM		4.35 ± 0.15e		2.93 ± 0.77e		0.150 ± 0.102fg

^aFor each experiment, monocytes were cultured with and without prior isolation of PBMC by use of Ficoll-Paque. 

^bMean channel number of autofluorescence (FL2 log). 

^cMean channel number of anti-CD4–PE signal. 

^dCorrected for autofluorescence. 

^eStatistically significant CD4 expression relative to autofluorescence; P < 0.050. 

^fStatistically significant reduction in CD4 expression relative to whole-blood monocytes; P < 0.050. 

^gStatistically significant reduction in CD4 expression relative to monocytes in whole-blood cultures; P < 0.050.