TNF and rheumatoid arthritis: There are only several publications showing the effect of low temperatures on concentration of cytokines in patients with RA, and the results are inconclusive; Fricke et al. [49] and Lange et al. [50] observed a significant decrease of TNF-α level after WBC [17, 49]; and changes of IL-6 level were observed by Straub et al. [17] and Fricke et al. [49].