Table 3.

Statistics for the regression analyses

	Linear regression					Exponential regression
Cytokine	R	R 2	p	A$\left(\frac{\mathit{pg}\mathbf{\times }\frac{\mathbf{1}}{\mathit{ml}}}{\mathbf{\mu }}\right)$	B$\left(\frac{\mathit{pg}}{\mathit{ml}}\right)$	R	R 2	p	K$\left(\frac{\mathbf{1}}{\mathit{\mu l}}\right)$	Y 0 × 10 −3 $\left(\frac{\mathit{pg}}{\mathit{ml}}\right)$
IL-9	0.48	0.23	0.008	−163.46	7.7 × 10−3	0.39	0.15	0.035	−0.04	5.6
IL-10	0.40	0.16	0.027	−97.15	7.6 × 10−3	0.56	0.32	0.001	−0.02	7.7
IL-12p40	0.87	0.76	0.000	−317.36	12.0 × 10−3	0.87	0.76	0.000	−0.05	12.0
IL-12p70	0.71	0.50	0.000	−379.48	19.0 × 10−3	0.74	0.54	0.000	−0.03	20.0
IL-17A	0.38	0.15	0.037	−266.41	18.5 × 10−3	0.11	0.01	0.547	−0.01	12.7
Eotaxin	0.65	0.42	0.000	−438.07	18.0 × 10−3	0.74	0.55	0.000	−0.05	19.0
KC	0.83	0.70	0.000	−960.63	27.0 × 10−3	0.91	0.83	0.000	−0.16	26.0
MCP-1	0.91	0.83	0.000	−156.83	6.0 × 10−3	0.91	0.82	0.000	−0.05	6.4
MIP-1β	0.74	0.55	0.000	−278.96	11.0 × 10−3	0.47	0.22	0.009	−0.04	7.6
RANTES	0.72	0.52	0.000	−20.70	0.9 × 10−3	0.65	0.42	0.000	−0.04	0.8

For cytokines that were significantly different between serum and heparin, the data were analyzed for a correlation between the concentration of the analyte and the amount of heparin added; R, R², p-values, slopes (A) and intercepts (B) for the linear regressions and intercepts (y₀) and coefficients (K) for the exponential regressions are given. The calculations are based on the addition of 1 μl or 10 μl heparin (5,000 IU/ml). Where significant, the relationship between the specific cytokine concentration (pg/ml) and heparin (X) volume (μl) can be described as [ Cyt ] =  B  +  A  ×  X or $\left[\mathit{Cyt}\right]={\mathbf{y}}_0\times {\mathit{e}}^{\left(-\mathit{K}\times \mathit{X}\right)}$.