A new study presented by researchers at the department of Immunology, Genetics and Pathology at Uppsala University in collaboration with colleagues at Karolinska Institute Medical University have produced a new tool for the prognosis and choice of therapy for rheumatoid arthritis by testing for antibodies against the cartilage protein collagen II.
“Analyzing these antibodies, in combination with other relevant antibodies, could be used for predicting prognosis and choosing therapy for rheumatoid arthritis patients,” says Professor Johan Rönnelid, who led the study.
Rheumatoid arthritis (RA) is a debilitating inflammatory disease where the joints become stiff and swollen and it is associated with progressive joint destruction. It is the result of autoantibodies that attack the joints causing inflammation, often presenting as pain and stiffness that worsens following rest—it commonly involves the wrists and hands on both sides of the body. In some RA patients, antibodies are formed that target collagen II, an important protein in joint cartilage that drives the inflammatory process early in the disease. The highest amount of collagen antibodies is detected at the time of diagnosis, which then typically decrease over the first year after diagnosis.
The researchers of this study followed a large group of RA patients during five years, looking for any connections between the collagen antibodies and disease development.
“We found that patients with collagen antibodies showed increased signs of inflammation during the first six months after diagnosis, after this there was no difference compared to patients without any collagen antibodies. We also discovered that the presence of collagen antibodies at the time of diagnosis was associated with a better prognosis,” says Vivek Anand Manivel, Ph.D. student at the Department of Immunology, Genetics and Pathology and first author of the article.
Current RA diagnosis practices commonly examine for the presence of antibodies against proteins called Citrullinated Peptides. In the group studied for antibodies targeting collagen II, the presence of such antibodies showed an opposite association to inflammation as compared to collagen antibodies. However, the presence of antibodies against Citrullinated Peptides was associated with increased inflammation later in RA follow-ups. There was an overall more severe disease course seen in patients with these antibodies.
“In all, our findings suggest that a combined analysis of antibodies against collagen and antibodies against citrullinated peptides could be a new tool for predicting the disease course and perhaps also for choosing therapy in newly diagnosed RA patients,” says professor Johan Rönnelid.