Are genetic variants of Caspase-1 and Cryopyrin associated with systemic JIA?

Background The systemic subtype of juvenile idiopathic arthritis (sJIA) can be the most severe, and unlike other forms of JIA is an autoinflammatory disease. There is evidence for the involvement of IL-1 in sJIA: treatment with the IL-1 receptor agonist, Anakinra, has shown dramatic improvement in some sJIA patients. Additionally we have shown a significant association with members of the IL-1 gene family and sJIA [1]. Caspase-1 is required to cleave IL-1β into its active form and Cryopyrin (NLRP3) is part if the IL-1β inflammasome, required for the activation of caspase-1. Mutations in NLRP3 have been found in patients that have similar clinical features with sJIA, e.g. CINCA. Here we describe a candidate gene association study of CASP1 and NLRP3 in sJIA.