In London, Ontario researchers at Lawson Health Research Institute have been studying Rheumatoid Arthritis (RA), and specifically the body's response to proteins found in the joints of these patients, in hopes of developing new strategies for the diagnosis and management of this debilitating disease.
Rheumatoid arthritis (RA) affects about 1 per cent of the adult population, which means approximately 300,000 Canadians likely suffer from the disease (Statistics Canada).
Rheumatoid arthritis generally affects people between the ages of 20 and 50. However, young children can develop a form of RA called juvenile rheumatoid arthritis.
Rheumatoid arthritis is an autoimmune disease, which means the body's natural immune system does not operate as it should and attacks healthy joint tissue, initiating a process of inflammation and joint damage. For more information go to Arthritis Research Centre of Canada
Rheumatoid Arthritis Research in Canada
In a Lawson Health Research Institute press release September 27, 2004, Dr. Ewa Cairns, Lawson scientist and co-investigator said, "research suggests that in the joints of patients with RA, proteins may be altered to contain an amino acid known as citrulline as part of the process that leads to inflammation of the rheumatoid joint."
Dr. Cairns, also a researcher in Rheumatology at London Health Sciences Centre, explained the team is researching antibodies that bind these modified proteins to gain a better understanding of the progress of the disease and thereby develop novel forms of therapy.
Rheumatoid Arthritis Difficult to Diagnose
According to Dr. David Bell, Lawson scientist, co-investigator, and Rheumatologist Physician in the Rheumatology Centre at St. Joseph's Health Care London, the ability to make a definite diagnosis of RA in the first few months of disease is often difficult.
Recent research involving antibodies that bind citrullinated proteins may be the answer as these antibodies have been found in earlier stages of RA.
Studies have shown that when the anti-citrulline antibody is found in a patient's blood, there is a greater than 95 per cent likelihood that the patient has RA. The anti-citrulline antibody test can then be used by doctors to encourage patients to proceed with the optimal treatments directed toward rheumatoid arthritis.
Early Detection of Rheumatoid Arthritis is Important
"A significant number of RA patients will quickly develop major disabilities and almost 50 per cent will experience work loss within 10 years of diagnosis," said Dr. Bell, "therefore early detection of RA and early aggressive treatment may have substantial long-term benefits."
Lawson researchers have discovered that citrullinated proteins found in the joints of RA patients can induce experimental arthritis in mice that contain a human gene that predisposes to the disease.
These results provide a new model to study autoimmune responses to citrullinated proteins, including the production of anti-citrulline antibodies. These results have been published in the Journal of Rheumatology (2004) and the Journal of Immunology (2004).
According to the researchers, the next step will be to see if they can somehow affect or alter the pathways that lead to the creation of citrullinated proteins or the production of anti-citrulline antibodies.
"By understanding how and why anti-citrulline antibodies develop, we can then work on finding ways to suppress the antibody, or block the enzymes responsible for making the citrullinated proteins," added Dr. Cairns.
This is good news for the thousands of people who suffer from RA. There is a large body of evidence showing that joint damage is an early phenomenon and if inadequately treated will progress relentlessly over time.
