Table 7.

Correlation between serum cytokine levels at baseline and residual DAS28 scores at 4 weeks after TCZ or IFX administration. Statistical significance of the correlation coefficient (r) was determined using Spearman’s rank correlation test (r > 0.3 or p < 0.05; data shown in bold type).

	TCZ Therapy
Cytokine (baseline)	DAS28/ESR4 (post-TCZ)		DAS28/CRP4 (post-TCZ)
Cytokine (baseline)	r	p	r	p

IL-1ß	−0.212	0.288	−0.287	0.155
IL-2	−0.153	0.447	−0.122	0.553
IL-6	0.427	0.026	0.416	0.035
IL-17A	NC	NC	NC	NC
IL-17F	0.186	0.352	−0.087	0.672
IFN-α	0.053	0.794	−0.199	0.329
TNF-α	−0.273	0.168	−0.360	0.071

	IFX Therapy
Cytokine (baseline)	DAS28/ESR4 (post-IFX)		DAS28/CRP4 (post-IFX)
Cytokine (baseline)	r	p	r	p

IL-1ß	0.078	0.700	0.073	0.718
IL-2	−0.072	0.723	−0.003	0.990
IL-6	0.083	0.686	0.229	0.261
IL-17A	−0.019	0.928	0.038	0.854
IL-17F	−0.157	0.441	0.027	0.895
IFN-α	−0.191	0.351	−0.030	0.885
TNF-α	0.183	0.361	0.150	0.454

NC: not calculable, because IL-17A levels at baseline were undetectable in this group. DAS28: 28-joint Disease Activity Score; TCZ: tocilizumab; IFX: infliximab; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; IL: interleukin; IFN: interferon; TNF: tumor necrosis factor.