Towards a New Clinico-Immunopathological Classification of Juvenile Inflammatory Arthritis: Figure 1.

Abstract

The classification of juvenile inflammatory arthritis (JIA) has been formulated against the well established dogma that pediatric “inflammation against self” is autoimmune in origin. Given that adult rheumatoid arthritis (RA) is a paradigm of such autoimmune disease, this comparator benchmark has been used for the categorization of the JIA spectrum of joint disease. Consequently, the etiopathogenesis of joint inflammation in polyarticular and oligoarticular JIA has been considered mostly in relationship to synovial-based disease. This includes the synovium that lines diarthrodial joints, but also synovium associated with bursae and tendon sheaths. In this issue of The Journal, Rooney and colleagues present a cross-sectional study in JIA patients with active, ankle-based disease using sonography to delineate the precise anatomical distribution of joint inflammation1. Specifically, they asked whether ankle joint swelling that was regarded as clinically significant affected the ankle joint itself, the tendons crossing the ankle joint, or both. The primary impetus for this work was to determine whether clinical assessment of disease with respect to anatomical territory involvement as joint cavity-based or tenosynovial-based was accurate. A better understanding of the precise localization of inflammation could have important implications for local steroid injection therapy in such cases. However, the authors did not attempt to specify which particular tendons were involved and in relation to which bony prominences — other than a passing reference to tibialis posterior (which uses the medial malleolus as a pulley in its journey between the … Address correspondence to Dr. McGonagle.