TY - JOUR T1 - Drs. Rudwaleit and Song reply JF - The Journal of Rheumatology JO - J Rheumatol SP - 1679 LP - 1680 VL - 35 IS - 8 AU - MARTIN RUDWALEIT AU - IN-HO SONG Y1 - 2008/08/01 UR - http://www.jrheum.org/content/35/8/1679.2.abstract N2 - To the Editor: The interesting comments by Kast and Altschuler further illustrate the complexity of the mechanisms underlying immune mediated injuries that have been observed in patients treated with anti-TNF agents and can affect a variety of organs1. As discussed in our case series2 of 4 patients (3 patients described in detail in the manuscript and a fourth patient added in proof) with ankylosing spondylitis who developed new onset of Crohn’s disease during etanercept therapy, we are currently far away from understanding the molecular pathways behind these unusual manifestations. Whether or not an increase of soluble TNF played a causative… ER -