[Indices of disease activity in systemic lupus erythematosus. Review of the literature]

Systemic lupus erythematosus is a multisystem autoimmune disease characterized by the production of autoantibodies reacting with many different self antigens. The analysis of clinical expression and evolution of this disease is a milestone in the definition of therapeutic strategies. A parameter universally accepted as gold standard is lacking so far. About 60 indices for defining and measuring the activity of this disease have been proposed in the last 20 years. The most important of these are discussed in this review, focusing both on their role in the evaluation and outcome of patients and on the main studies assessing their validity and reliability.