Favorable radiological outcome of skeletal Erdheim-Chester disease involvement with anakinra

Erdheim-Chester disease is a rare non-langerhans cell histiocytosis characterized by infiltration of foamy CD68-positive but CD1a-negative macrophages and fibro-inflammatory lesions as retroperitoneal, periureteral areas or bones. Interferon-alpha therapy has been used as treatment but it had variable efficiency and limited tolerance. More recently, a recombinant form of interleukin-1 receptor antagonist (anakinra) was used with success but no skeletal radiological improvement was recorded. We report here a case of interleukin-1 receptor antagonist in the treatment of refractory bones infiltration in Erdheim-Chester disease. After 1 year of treatment, the positron emission tomography-computed tomography showed an outstanding response of the skeletal involvement with clearly lower and smaller hypermetabolism images. (C) 2012 Societe francaise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.