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Table 1 Temporal reproducibility of EDTA plasma biomarkers measured by Luminex xMap™, NSHDS subjects a (n = 18 pairs)

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

Biomarker LLD First Sample Second Sample Intra-batch CV ICC (95% CI)
   % Above LLD Median (25%, 75%) % Above LLD Median (25%, 75%)    
hsIL-1β (pg/mL)b 0.06 100 8.1 (5.5, 11.3) 100 8.0 (4.6, 10.1) 2.0% 0.73 (0.43-0.89)
hsIL-2 (pg/mL)b 0.16 100 28.8 (18.9, 39.1) 100 31.3 (20.8, 39.9) 2.7% 0.80 (0.56-0.92)
sIL-2R (pg/ml)c 30 100 652 (624, 789) 100 691 (624, 762) 1.0% 0.86 (0.68-0.95)
IL-4 (pg/mL)c 5 100 140 (114, 163) 100 120 (109, 143) 1.6% 0.00 (-0.45-0.45)
hsIL-4 (pg/mL)b 0.13 100 50.5 (31.4, 80.7) 100 42.4 (16.2, 83.0) 2.7% 0.70 (0.36-0.87)
hsIL-5 (pg/mL)b 0.01 100 3.4 (1.8, 4.6) 100 3.2 (1.8, 4.2) 2.5% 0.73 (0.41-0.89)
hsIL-6 (pg/mL)b 0.10 100 20.4 (15.9, 28.7) 100 18.4 (13.8, 24.3) 2.0% 0.81 (0.56-0.92)
sIL-6R (ng/mL)c 0.024 100 29.0 (26.5, 42.6) 100 29.8 (25.2, 36.4) 0.3% 0.69 (0.36-0.87)
hsIL-7 (pg/mL)b 0.12 100 10.1 (6.5, 15.7) 94.4 10.7 (6.1, 13.7) 3.3% 0.55 (0.14-0.80)
hsIL-8 (pg/mL)b 0.11 100 9.3 (6.4, 11.8) 100 8.3 (5.3, 10.5) 1.6% 0.86 (0.68-0.95)
hsIL-10 (pg/mL)b 0.15 100 40.7 (26.7, 57.2) 100 33.2 (15.8, 56.3) 2.1% 0.75 (0.46-0.90)
IL-12p40 (pg/mL)c 15 100 410 (379, 471) 100 413 (402, 447) 0.7% 0.89 (0.73-0.96)
hsIL-12p70 (pg/mL)b 0.11 100 32.3 (21.5, 46.5) 100 26.0 (11.8, 40.7) 2.1% 0.77 (0.50-0.91)
hsIL-13 (pg/mL)b 0.48 100 45.7 (30.5, 51.9) 100 39.6 (15.4, 50.2) 3.0% 0.81 (0.56-0.92)
CRP (μg/mL)b 0.000002 100 10.6 (3.1, 17.1) 100 8.5 (4.0, 16.9) 1.9% 0.76 (0.48-0.90)
IFNα (pg/mL)c 15 100 45.8 (41.1, 70.7) 100 50.2 (37.8, 80.7) 5.1% 0.53 (0.11-0.79)
IFNγ (pg/mL)c 5 100 175 (108, 199) 100 118 (95.3, 162) 1.8% 0.00 (-0.45-0.45)
hsIFNγ (pg/mL)b 0.29 100 78.3 (42.6, 99.4) 100 65.0 (43.4, 103) 2.2% 0.72 (0.41-0.89)
hsTNFα (pg/mL)b 0.05 100 8.0 (6.2, 11.2) 100 8.4 (5.8, 10.9) 1.9% 0.69 (0.36-0.87)
sTNF-R1 (ng/mL)c 0.015 100 1.3 (1.2, 1.8) 100 1.2 (0.9, 1.6) 1.7% 0.31 (-0.16-0.67)
sTNF-R2 (ng/mL)c 0.015 100 1.1 (0.72, 1.2) 100 0.9 (0.7, 1.1) 0.5% 0.68 (0.33-0.86)
Growth Factors           
EGFR (ng/mL)d 0.020 100 15.4 (14.1, 15.9) 100 15.3 (13.9, 16.6) 0.5% 0.93 (0.83-0.97)
ErbB2 (ng/mL)d 0.017 100 3.4 (2.9, 3.6) 100 3.2 (3.0, 3.8) 0.5% 0.63 (0.26-0.84)
hsGM-CSF (pg/mL)b 0.46 100 38.2 (29.6, 52.4) 100 33.5 (21.9, 39.9) 2.9% 0.47 (0.03-0.76)
G-CSF (pg/mL)c 15 100 129 (108, 167) 100 129 (108, 160) 6.4% 0.75 (0.46-0.90)
HGF (pg/mL)c 10 100 151 (101, 186) 100 196 (101, 278) 1.1% 0.74 (0.43-0.89)
  1. Note: LLD = lower limit of detection as reported by the manufacturer, CVs are based on 8 blinded duplicates
  2. a Limited to the biomarkers for which more than 70% of all the samples were detectable. There were no extrapolated values for any of the markers included in the table except for 1 sample for IFNα. 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 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).
  3. b Kits from Linco/Milliporec Kit from Biosource
  4. d Kit developed in-house