MIF and TNFα serum levels in rheumatoid arthritis patients treated with disease-modifying antirheumatic drugs: a cross-sectional study

Abstract

Macrophage migration inhibitory factor (MIF) and tumor necrosis factor alpha (TNFα) play a pivotal role in rheumatoid arthritis (RA). MIF is considered a relevant cytokine because it appears before TNFα in the inflammatory cascade thus stimulating TNFα production and MIF’s relationship with traditional synthetic disease modifying antirheumatic drugs (sDMARDs) is unknown. In this cross-sectional study, we investigated the association of MIF and TNFα serum levels with methotrexate (MTX) and in combination with chloroquine (CLQ) and sulfasalazine (SSZ) in RA patients classified according to the ACR/EULAR 2010 criteria. Patients were divided into three groups: MTX-monotherapy group (n = 40), MTX combination therapy groups: MTX + CLQ (n = 41), and MTX + CLQ + SSZ (n = 42). MIF and TNFα serum levels were determined by ELISA. We found high levels of ESR, CRP, RF, and anti-CCP in all therapy groups. Furthermore, we subclassified 97 patients with established RA (≥2 years of disease duration) and found that TNFα serum levels were lower in the combination therapy group (MTX + CLQ + SSZ) in comparison with the monotherapy MTX group (16.7 pg/mL versus 13.6 pg/mL, p = 0.02). However, we did not find differences between sDMARD therapies in MIF serum levels. We did find a significant reduction in MIF serum levels in patients treated with oral steroids compared with patients without oral steroids (1.7 ng/mL versus 4.3 ng/mL, p < 0.001). In conclusion, this study supports the role of sDMARDs in modifying TNFα serum levels and oral steroids MIF serum levels. Nevertheless, we found that MIF serum levels are not modified by sDMARD treatment.