Pathophysiological advances underlying the biotherapeutic revolution in inflammatory rheumatism

Major advances have been made in the pathogenesis of rheumatoid arthritis, spondyloarthritis and connective tissue diseases, leading to new biotherapies. In rheumatoid arthritis, the discovery of anti-citrulline antibodies (ACPA, anti-citrullinated peptide antibodies), whose specificity is between 95 % and 98 % and may be present before symptom onset, allowed early diagnosis and provided new pathological insights. Studies of the role of cytokines; B cells and co-stimulation of T cells revealed novel therapeutic targets. TNF inhibitors are effective in spondyloarthritis. In lupus and Sjogren's syndrome, genes stimulatedby IFN type I are hyper-expressed, along with BAFF (or BLyS), a B lymphocyte-activating cytokine.