TABLE 4.

Correlation coefficients of ≥0.35 between serum cytokine levels and nonmatching intracellular cytokines^a

Serum cytokine	Cell type	Intracellular cytokine(s)	Stimulation statusb	Coefficient	Testc	No.
IL-2	None	NAd	NA	NA	NA	44
IL-4	NA	NA	NA	NA	NA	0
IL-6	None	NA	NA	NA	NA	87
IL-8	Lymphocytes	IFN-γ	S	−0.39	Sp	128
	Lymphocytes	IFN-γ and TNF-α	S	−0.42	Sp	128
	Lymphocytes	IFN-γ and IL-6	S	−0.39	Sp	124
	Lymphocytes	IL-2 and IL-10	U	−0.41	Sp	127
	CD3+ cells	IL-2	S	−0.35	Sp	128
	CD3+ cells	IFN-γ	S	−0.49	Sp	128
	CD3+ cells	IFN-γ and TNF-α	S	−0.37	Sp	127
	CD3+ CD8+ cells	IFN-γ	S	−0.39	Sp	120
	CD3+ CD8− cells	IFN-γ	S	−0.37	Sp	120
IL-10	None	NA	NA	NA	NA	83
IFN-γ	Lymphocytes	IFN-γ and IL-6	U	+0.48	P	91
TNF-α	None	NA	NA	NA	NA	83

^aCorrelations between percentages of cells making cytokine and serum cytokine levels. Included only if trend remained with outliers excluded. All values for serum IL-4 levels were nondetectable (below 15.6 pg/ml); therefore, trends could not be assessed. 

^bUnstimulated cells (U) and cells stimulated with PMA and ionomycin (S) (both with brefeldin A). 

^cAll P values <0.0001 Abbreviations: P, Pearson; Sp, Spearman. 

^dNA, nonapplicable.