Skip to main content

Table 2 Correlation between EDTA plasma versus serum biomarkers measured by Luminex xMap™, clinical research study subjects a (n = 18 pairs)

From: Temporal reliability of cytokines and growth factors in EDTA plasma

Biomarker

Plasma

Serum

Plasma vs.

Serum Paired

Relative

Difference

(%)

p-value

(Wilcoxon Signed-

Rank Test)

Spearman

Correlation

Coefficient

(rs)

rs

p-value

 

%

Above

LLD

Median

(25%, 75%)

%

Above

LLD

Median

(25%, 75%)

Median

(25%, 75%)

   

Cytokines

           

hsIL-1β (pg/mL)b

100

5.1

(3.4, 7.5)

94.4

3.5

(2.5, 8.9)

14

(-14, 42)

0.548

0.83

0.000

hsIL-2 (pg/mL)b

100

18.8

(9.8, 25.7)

100

17.4

(7.4, 35.6)

-2.3

(-39, 38)

0.799

0.69

0.002

sIL-2R (pg/ml)c

100

658

(602, 746)

100

660

(527, 831)

-4.7

(-17, 11)

0.459

0.72

0.001

IL-4 (pg/mL)c

100

141

(108, 181)

100

113

(96.4, 123)

19

(-3.3, 46)

0.009

-0.02

0.922

hsIL-4 (pg/mL)b

100

56.3

(27.9, 91.4)

100

63.0

(34.4, 108)

-15

(-41, 11)

0.159

0.28

0.265

hsIL-5 (pg/mL)b

100

2.3

(1.4, 3.1)

94.4

2.6

(0.8, 3.9)

11

(-16, 44)

0.459

0.77

0.000

hsIL-6 (pg/mL)b

100

20.3

(12.6, 35.7)

100

28.9

(13.3, 43.6)

-2.2

(-41, 7.6)

0.369

0.77

0.000

sIL-6R (ng/mL)c

100

27.5

(26.0, 34.6)

100

59.1

(47.9, 91.9)

-102

(-189, -68)

0.000

0.39

0.113

hsIL-7 (pg/mL)b

100

14

(9, 16.9)

94.4

14.8

(13.3, 18.6)

-32

(-80, 5.3)

0.008

0.64

0.006

hsIL-8 (pg/mL)b

100

10.3

(6, 21.5)

100

13.3

(7.9, 26.2)

-20

(-59, -1.8)

0.002

0.90

0.000

hsIL-10 (pg/mL)b

100

31.8

(19.9, 40.2)

100

25.5

(11.2, 48.8)

20

(-23, 30)

0.442

0.73

0.001

IL-12p40 (pg/mL)c

100

417

(361, 602)

100

417

(358, 537)

-0.4

(-6.9, 3.0)

0.393

0.96

0.000

hsIL-12p70 (pg/mL)b

100

20.8

(14.8, 32.6)

100

29.1

(16.5, 59.9)

-14

(-112, 1.3)

0.030

0.77

0.000

hsIL-13 (pg/mL)b

100

27.2

(19.6, 33.8)

100

32.6

(22.3, 53)

-20

(-56, 14)

0.057

0.66

0.003

CRP (μg/mL)b

100

20.5

(7.4, 35.7)

100

22.2

(8.6, 40.2)

-11

(-20, 4.1)

0.081

0.95

0.000

IFNα (pg/mL)c

100

42.7

(34.2, 53)

100

37.8

(34.2, 47.3)

4.1

(-20, 31)

0.318

-0.05

0.840

IFNγ (pg/mL)c

100

166

(125, 262)

100

83.0

(73.9, 91.1)

56

(20, 70)

0.000

-0.17

0.500

hsIFNγ (pg/mL)b

100

45.4

(25.4, 61)

94.4

38.4

(18.2, 78.8)

4.1

(-42, 40)

0.927

0.68

0.003

hsTNFα (pg/mL)b

100

10.7

(9.6, 13)

100

10.4

(8.6, 15)

-6.9

(-26, 8.8)

0.196

0.71

0.001

sTNF-R1 (ng/mL)c

100

1.5

(1.4, 1.8)

100

1.6

(1.1, 2.0)

-6.6

(-21, 14)

0.442

0.75

0.000

sTNF-R2 (ng/mL)c

100

1.4

(1.1, 1.8)

100

1.7

(1.2, 1.9)

-5.0

(-12, 0.1)

0.009

0.94

0.000

Growth Factors

           

EGFR (ng/mL)d

100

13.7

(12.6, 14.8)

100

18.1

(17.1, 20.2)

-28

(-44, -18)

0.000

0.48

0.045

ErbB2 (ng/mL)d

100

3.6

(3.2, 4.1)

100

3.7

(3.1, 4.0)

-6.8

(-9.4, -1.6)

0.142

0.72

0.001

hsGM-CSF (pg/mL)b

100

21.3

(17.4, 31.3)

94.4

28.7

(19, 53.4)

-9.9

(-47, 8.1)

0.174

0.79

0.000

G-CSF (pg/mL)c

100

125

(99.6, 149)

100

91.4

(83, 123)

9.0

(-13, 34)

0.156

0.45

0.059

HGF (pg/mL)c

100

230

(205, 307)

100

380

(253, 687)

-50

(-165, -20)

0.000

0.72

0.001

  1. Note: LLD = lower limit of detection
  2. a Limited to the biomarkers for which more than 70% of all the samples were detectable. Values were extrapolated below the standard curve for less than 14% of samples for hsIL-5, IFNα, and IL-6R, but were not extrapolated for any other markers included in the table. Sixteen markers are not included because more than 30% of samples were undetectable (IL-1β, IL-1RA, IL-5, IL-6, IL-17, VEGF), and/or a high percentage of the samples were extrapolated below the lowest point on the standard curve (IL-1α, IL-2, IL-7, IL-8, IL-10, IL-13, IL-15, TNFα, EGF, bFGF).b Kits from Linco/Milliporec Kit from Biosource
  3. d Kit developed in-house