Multiplex Cytokine Concentration Measurement: How Much Do the Medium and Handling Matter?

Table 1

Intraclass correlations (ICCs) and their 95% confidence intervals (CI); mean differences between the two measurements and their 95% confidence intervals; 95% limits of agreement which are expected to include 95% of the differences between the two measurements. Statistically significant values (𝑃<0.05) are denoted by bold font and *.

Cytokine	Baseline plasma versus baseline serum			Baseline plasma versus thawed plasma			Baseline serum versus thawed serum
	ICC (95% CI)	Mean diff. (95% CI)	95% limits of agreement	ICC (95% CI)	Mean diff. (95% CI)	95% limits of agreement	ICC (95% CI)	Mean diff. (95% CI)	95% limits of agreement
IL-1β	0.16 (−0.27, 0.53)	−1.36 (−4.91, 2.19)	−17.45, 14.73	𝟎.𝟗𝟎^∗ (0.69, 0.97)	−0.13 (−0.55, 0.29)	−1.43, 1.17	0.00 (−0.53, 0.53)	0.42 (−0.24, 1.09)	−1.73, 2.57
IL-2	—	—	—	—	—	—	—	—	—
IL-4	0.03 (−0.33, 0.42)	0.60 (−0.81, 2.00)	−5.62, 6.82	−0.15 (−0.667, 0.467)	−1.33 (−4.44, 1.77)	−10.41, 7.74	0.00 (−0.576, 0.576)	0.91 (−0.69, 2.50)	−3.74, 5.56
IL-5	0.14 (−0.25, 0.50)	−1.06 (−3.25, 1.12)	−10.73, 8.61	−0.41 (−0.92, 0.29)	−0.64 (−5.08, 3.81)	−13.60, 12.33	−0.11 (−0.72, 0.52)	0.01 (−2.70, 2.72)	−7.90, 7.91
IL-6	0.00 (−0.40, 0.39)	−1.91 (−20.69, 16.87)	−87.02, 83.20	0.41 (−0.13, 0.77)	7.07 (−11.18, 25.33)	−52.13, 66.28	0.00 (−0.60, 0.60)	−0.18 (−0.60, 0.23)	−1.32, 0.95
IL-7	−0.21 (−0.57, 0.21)	−12.91 (−39.43, 13.61)	−133.11, 107.28	𝟎.𝟕𝟎^∗ (0.23, 0.91)	−0.64 (−19.54, 18.25)	−58.93, 57.65	𝟎.𝟖𝟖^∗ (0.62, 0.96)	−5.66 (−16.43, 5.11)	−37.07, 25.75
IL-8	0.04 (−0.38, 0.44)	−7.36 (−25.36, 10.65)	−88.97, 74.25	−0.01 (−0.66, 0.61)	−7.52 (−30.58, 15.55)	−70.72, 55.69	𝟎.𝟓𝟓^∗ (0.02, 0.85)	−20.28 (−45.39, 4.83)	−93.54, 52.98
TNF-α	−0.14 (−0.55, 0.31)	−20.37 (−78.00, 37.25)	−275.11, 234.36	−0.21 (−0.82, 0.46)	−7.34 (−45.92, 31.23)	−119.89, 105.20	0.17 (−0.47, 0.68)	−51.92 (−186.80, 82.95)	−445.41, 341.57
IFN-γ	0.07 (−0.36, 0.47)	−73.44 (−264.42, 117.53)	−917.68, 770.80	−0.09 (−0.64, 0.54)	19.86 (−19.26, 58.98)	−87.32, 127.05	0.00 (−0.60, 0.60)	11.59 (−14.63, 37.82)	−60.26, 83.44
IL-10	—	—	—	—	—	—	𝟎.𝟗𝟗^∗ (0.98, 1.00)	−6.52 (−200.48, 187.43)	−604.84, 591.80
IL-12p70	0.19 (−0.22, 0.55)	19.11 (−15.21, 53.43)	−140.18, 178.40	0.28 (−0.31, 0.72)	29.81 (−37.43, 97.04)	−177.60, 237.21	𝟎.𝟓𝟖^∗ (0.08, 0.85)	3.27 (−8.19, 14.74)	−32.09, 38.64
IL-13	0.00 (−0.43, 0.43)	2.30 (−0.92, 5.52)	−10.81, 15.41	0.00 (−0.60, 0.60)	0.66 (−5.48, 6.80)	−15.00, 16.32	𝟎.𝟗𝟔^∗ (0.87, 0.99)	−0.31 (−2.00, 1.38)	−5.23, 4.61
IL-17	0.00 (−0.40, 0.40)	2.25 (−2.42, 6.92)	−18.90, 23.40	—	—	—	𝟎.𝟔𝟓^∗ (0.14, 0.89)	34.66 (−42.57, 111.88)	−190.64, 259.96
G-CSF	0.18 (−0.13, 0.52)	𝟓𝟖.𝟓𝟑^∗ (15.59, 101.46)	−121.29, 238.34	−0.09 (−0.71, 0.54)	−19.24 (−98.03, 59.54)	−249.10, 210.61	0.00 (−0.45, 0.54)	37.64 (−11.71, 86.98)	−106.33, 181.61
GM-CSF	—	—	—	—	—	—	—	—	—
MCP-1	0.10 (−0.32, 0.49)	−22.26 (−74.18, 29.66)	−257.59, 213.06	0.09 (−0.44, 0.60)	−28.19 (−78.02, 21.64)	−181.89, 125.51	0.50 (−0.02, 0.82)	−57.60 (−112.55, −2.65)	−227.12, 111.92
MIP-1β	0.38 (−0.03, 0.70)	−𝟐𝟓𝟑.𝟑𝟕^∗ (−442.17, −64.57)	−1021.11, 514.37	0.20 (−0.52, 0.72)	−63.71 (−343.30, 215.87)	−829.75, 702.32	𝟎.𝟕𝟐^∗ (0.25, 0.92)	−137.73 (−357.49, 82.02)	−739.84, 464.38
log MIP-1β	𝟎.𝟕𝟐^∗ (0.29, 0.89)	−0.62 (−1.07, −0.18)	−2.44, 1.19	0.59 (−0.66, 0.90)	−0.28 (−0.98, 0.43)	−2.21, 1.66	0.63 (−0.49, 0.91)	−0.48 (−1.13, 0.16)	−2.24, 1.27