IL6 and rheumatoid arthritis: However, the fundamental feature of rheumatoid cachexia appears to be an excess of the pro-inflammatory cytokines that are involved in RA (TNF-a, IL-1B, IL-6, and IFN-y) which leads to increased muscle wasting and protein degradation (Cooney et al., 2011; Masuko, 2014; Londhe and Guttridge, 2015).