Rheumatoid arthritis (RA) is a long-term autoimmune disorder in which the body's immune system attacks joints on both sides of the body, causing inflammation, pain, swelling and loss of joint function. The disease affects everyone differently and treatments include medicine, lifestyle changes, and surgery. In RA, antibodies are produced that impact the inflammation in the joints.
In a paper in the Annals of Rheumatic Diseases, a team led by researchers from Uppsala University, Karolinska University Hospital and Karolinska Institutet, and Karolinska Institutet in Sweden has found that antibodies against the cartilage protein collagen II may help predict prognosis and choose therapy for RA. These antibodies seem to be linked with a good prognosis.
A certain percentage of RA patients have antibodies produced to collagen II, a structural protein that is the basis for articular cartilage and hyaline cartilage in the joint. These antibodies contribute to inflammation early in the disease but decrease over time.
The study enrolled a group of 773 RA patients from the Swedish Epidemiological Investigation in Rheumatoid Arthritis study. The team followed the patients for as long as five years. Using the method ELISA to measure the levels of antibodies against collagen II and citrullinated peptides, they identified that subjects who had collagen antibodies exhibited severer inflammation during the first six months after diagnosis, after this there was no difference compared to subjects who did not have collagen antibodies. In addition, subjects who had collagen antibodies at diagnosis were more likely to have better outcomes. In contrast, subjects with antibodies against citrullinated peptides had increased inflammation later in disease progression and tended to have worse outcomes.
RA is a multifactorial disease. Some patients have rheumatoid factor and/or anticitrullinated protein peptide autoantibodies while others do not. The study indicates that the combined analysis of antibodies against collagen II and citrullinated peptides "may be a new two-dimensional tool for predicting the prognosis and choosing therapy in newly diagnosed patients with RA." Johan Ronnelid from Department of Immunology, Genetics and Pathology of Uppsala University is the study leader.
-whcaroline-
Rheumatoid arthritis is often a quite difficult disease to diagnose since there are many conditions which could be responsible for causing the inflammation and joint stiffness. This means that there is no one definitive test for this condition.
Specific blood tests are often used for diagnosis but these aren’t always accurate for everyone. For example an antibody test that is known as anti-CCP (anti-cyclic citrullinated peptide) is available (http://www.elisakits.co.uk/anti-ccp-elisa-kit). However, people who test positive for anti-CCP are known to be highly likely to develop rheumatoid arthritis, but not everyone who has rheumatoid arthritis displays this antibody.
Also, approx. half of individuals with rheumatoid arthritis have a positive rheumatoid factor present in their blood at the start of the disease, however, this is made harder by the fact that one in 20 people without rheumatoid arthritis also tests positive.
In general, it is widely accepted that anybody who has a positive test for both anti-CCP and rheumatoid factor are more likely to have severe rheumatoid arthritis which will need high level of treatment.
-Paul Davies-
