Table 2.
Concentration changes of analytes induced by repeated freezing and thawing of serum samples.
| Analyte (pg/mL) |
Freeze–thaw cycles |
p | |||
|---|---|---|---|---|---|
| 2 cycles (baseline) | 3 cycles∗ | 4 cycles∗ | 5 cycles∗ | ||
| IFN-γ | 8.11 ± 12.98 | 8.66 ± 14.13 | 8.82 ± 14.71 | 8.36 ± 13.76 | 0.327 |
| (+6.8) | (+8.8) | (+3.2) | |||
| IL-8 | 35.54 ± 71.31 | 36.25 ± 71.46 | 36.40 ± 71.28 | 34.22 ± 67.01 | 0.208 |
| (+2.0) | (+2.4) | (–3.7) | |||
| IL-15 | 1.54 ± 0.74 | 1.67 ± 0.73† | 1.73 ± 0.71† | 1.46 ± 0.66 | 0.001 |
| (+8.7) | (+12.4) | (–4.7) | |||
| IL-17A | 3.07 ± 3.45 | 3.59 ± 4.06† | 3.29 ± 3.61 | 3.02 ± 3.39 | 0.110 |
| (+17.2) | (+7.4) | (–1.6) | |||
| MMP7 | 2.48 ± 1.50 | 2.59 ± 1.57† | 2.65 ± 1.43† | 2.64 ± 1.41† | 0.004 |
| (+4.1) | (+6.9) | (+6.5) | |||
| TNF-α | 8.74 ± 5.09 | 9.04 ± 5.63† | 9.17 ± 5.80† | 8.82 ± 5.57 | 0.126 |
| (+3.4) | (+4.9) | (+0.9) | |||
| VEGF | 195.13 ± 99.52 | 197.53 ± 97.88 | 197.21 ± 97.99 | 208.84 ± 108.75† | 0.107 |
| (+1.2) | (+1.1) | (+7.0) | |||
| VEGFR2 | 9,230.32 ± 1,877.97 | 9,264.60 ± 1,874.35 | 9,237.86 ± 1,806.16 | 9,267.74 ± 1,845.64 | 0.877 |
| (+0.4) | (+0.1) | (+0.4) | |||
IFN = interferon; IL = interleukin; MMP = matrix metalloproteinase; TNF = tumor necrosis factor; VEGF = vascular endothelial growth factor.
∗
Values within“( )” show the percentage change with a “+” for an increase and a “–” for a decrease compared with baseline.
†
Indicates p < 0.05 calculated with paired 2-tailed t test. The p value was measured with repeated-measures analysis of variance.