TNF and rheumatoid arthritis: In seropositive and seronegative RA, as well as in high-risk seropositive arthralgia patients, there was an overlap in circulating cytokine profiles with IFN-α, as well as IL-5, and TNF-α upregulated up to 50% in seropositive arthralgia and seropositive RA patients but not in seronegative RA [21] with an odds ratio (OR) of 21 for RA development in seropositive arthralgia patients [18, 21].