TNF and juvenile idiopathic arthritis: Azfar et al. have shown that lupus patients have suppressed reactive oxygen species and tumour necrosis factor-alpha activity in human monocytes in response to mycobacterium TB.27 Previously, the risk of TB has been shown to be increased in children with JIA independent of the use of anti-TNFs.28,29 However, in this study, the risk of TB was equal to the general population for children who either received anti-TNFs, or non TNF biological agents.