The Systemic Lupus Erythematosus Responder Index (SRI); a new SLE disease activity assessment

Systemic Lupus Erythematosus (SLE), because of its complex and multisystemic presentation, lacks a reliable and sensitive gold standard for measuring disease activity. In addition, there is no standardized method for defining response to therapy. Several disease activity indices have been developed over the years, each with their own positive and negative aspects. Growing insight in the pathogenesis of inflammatory diseases like SLE leads to the introduction of specific targeted biologic therapies. To investigate the efficacy of these new biologic agents, disease activity must be monitored regularly by a reliable and validated instrument. Recent studies on new biologics for treatment of SLE use a new composite measurement for disease activity and response in SLE. This new disease activity assessment, called SLE Responder Index (SRI), comprises criteria from three different internationally validated indices, SELENA-SLE Disease Activity Index (SELENA-SLEDAI), Physician Global Assessment (PGA) and the British Isles Lupus Assessment Group (BILAG) 2004. This review gives an overview of current available disease activity indices in relation to the newly developed composite SRI.