Comment on ‘Sustained discontinuation of infliximab with a raising-dose strategy after obtaining remission in patients with rheumatoid arthritis: the RRRR study, a randomised controlled trial’ by Tanaka et al

We have read with interest the paper of Tanaka et al 1 and support the need for a more personalised approach in dosing regimens of tumour necrosis factor (TNF) inhibitors.2 They adjusted infliximab dose based on TNF concentrations at baseline, under the assumptions that baseline TNF concentrations can be accurately measured, and that high disease activity (ie, more inflammation) is associated with higher TNF concentrations. However, several factors argue against these assumptions, which we would like to add to the study by Tanaka et al . These factors might explain the absence of an association between TNF concentrations and treatment response. First, the quantification of TNF at baseline is in fact challenging: TNF is an unstable molecule with a …