Univariate and multivariate association between smoking and cytokine levels in patients with SLE
| Univariate | Age and sex adjusted | Model 1 | Model 2 | |||||
| Rs | P value | B (95% CI) | P value | B (95% CI) | P value | B (95% CI) | P value | |
| Ln(BAFF) | 0.20 | 0.043 | 0.24 (0.03 to 0.45) | 0.023 | 0.25 (0.05 to 0.45) | 0.015 | 0.27 (0.06 to 0.48) | 0.014 |
| Ln(IFN-γ) | −0.32 | 0.001 | −0.79 (−1.25 to 0.32) | 0.001 | −0.80 (−1.27 to 0.33) | 0.001 | −0.42 (−0.79 to 0.05) | 0.026 |
| Ln(IL-1β) | −0.19 | 0.054 | −0.42 (-0.82 to 0.02) | 0.039 | −0.38 (−0.78 to 0.02) | 0.062 | –* | – |
| Ln(IL-4) | −0.25 | 0.015 | −0.47 (0.98 to 0.02) | 0.060 | −0.43 (−0.92 to 0.07) | 0.089 | −0.03 (−0.27 to 0.20)** | −0.778 |
| Ln(IL-6) | −0.15 | 0.142 | −0.26 (−0.61 to 0.09) | 0.088 | −0.24 (−0.59 to 0.11) | 0.183 | −0.06 (−0.35 to 0.23) | 0.666 |
| Ln(IL-10) | −0.04 | 0.725 | −0.42 (−0.96 to 0.12) | 0.123 | −0.35 (−0.89 to 0.18) | 0.195 | 0.03 (−0.28 to 0.35)# | 0.832 |
| Ln(IL-12) | −0.19 | 0.055 | −0.51 (−0.93 to 0.08) | 0.021 | −0.46 (−0.89 to 0.03) | 0.038 | −0.09 (−0.41 to 0.22) | 0.588 |
| Ln(IL-17) | −0.12 | 0.237 | −0.43 (−0.80 to 0.06) | 0.022 | −0.41 (−0.78 to 0.03) | 0.034 | −0.20 (−0.46 to 0.07) | 0.146 |
| Ln(MCP-1) | −0.16 | 0.104 | −0.24 (−0.55 to 0.07) | 0.129 | −0.24 (−0.56 to 0.07) | 0.124 | −0.12 (−0.43 to 0.19) | 0.435 |
| Ln(TNF-α) | −0.24 | 0.016 | −0.55 (−0.99 to 0.11) | 0.014 | −0.54 (−0.98 to 0.09) | 0.019 | −0.25 (−0.60 to 0.10) | 0.155 |
| Ln(TGF-β1) | −0.17 | 0.1 | −0.20 (−0.41 to 0.02) | 0.076 | −0.21 (−0.43 to 0.01) | 0.062 | −0.18 (−0.41 to 0.05)% | 0.118 |
| Ln(MIP-1α) | −0.13 | 0.21 | −0.28 (−0.90 to 0.35) | 0.381 | −0.19 (−0.81 to 0.43) | 0.55 | 0.16 (−0.41 to 0.73) | 0.580 |
| Ln(MIP-1β) | −0.27 | 0.007 | −0.27 (−0.49 to 0.06) | 0.011 | −0.26 (−0.47 to 0.05) | 0.014 | −0.13 (−0.31 to 0.05) | 0.159 |
Model 1 adjusted for age, sex, prednisone use, immunosuppressant use, SLEDAI score, SDI score.
Model 2 adjusted for model 1 plus (regulatory cytokine) IL-1β* and anti-inflammatory cytokines (IL-4**, IL-10# and TGF-β%) (*, **, #, % indicate that this cytokine was dropped from the independent variables of the model).
Bolded findings: current smoking associated with changes (+/-) in the level of the cytokine of interest smoking.
BAFF, B cell-activating factor; IFN-γ, interferon-gamma; IL, interleukin; MCP-1, monocyte chemoattractant protein 1; MIP-1α, macrophage inflammatory protein 1 alpha; MIP-1β, macrophage inflammatory protein 1 beta; SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; SLEDAI, SLE Disease Activity Index; TGF-β1, transforming growth factor beta 1; TNF-α, tumour necrosis factor-alpha.