Serological Diagnosis of Rheumatoid Arthritis
In addition to rheumatoid factor the detection of ACPAs (ACPA stands for anti-citrullinated protein/peptide antibody) has become a standard procedure in the diagnosis of rheumatoid arthritis (RA) and has recently been included in the updated official criteria for classification of rheumatoid arthritis defined by the ACR (American College for Rheumatology)1,2,3,. The use of ACPAs allows physicians to predict the progression of the disease4,5), and some of these autoantibodies also seem to be a good and objective measurement of disease activity and the effectiveness of treatment for rheumatoid arthritis6,7). If these early results from international studies are borne out, this would be a significant step forward for the diagnosis and treatment of rheumatoid arthritis, which is the most common autoimmune disease overall and affects nearly one percent of the world's population.
It is known that certain ACPAs are directly involved in the development of rheumatoid arthritis, in that they bind to components of the body's own articular cartilage8). This attracts scavenger cells, which release inflammatory signal substances like tumor necrosis factor-alpha and interleukins, as well as joint-degrading enzymes like elastase and other proteases. This causes a flare up of inflammation, which the body can no longer control. The result is fatal: the joints are eventually destroyed.