What's new in ... Rheumatology and Autoimmune Diseases

Investigations Rheumatoid factor is 60–70% sensitive and 80% specific for the diagnosis of rheumatoid arthritis (RA). Antibodies to citrullinated proteins (anti-CCP) are less sensitive but more specific (95%) for RA1 and predict radiographic joint damage.2 Use of anti-CCP complements that of IgM rheumatoid factor in the diagnosis of early RA, but does not replace clinical signs and symptoms because a significant minority of patients do not have either antibody.