A research team from the Johns Hopkins University School of Medicine has made a discovery that could open the door to early diagnosis of severe rheumatoid arthritis (RA) and to novel, more aggressive therapies for such patients. The researchers have found a specific subset of antibodies in the blood of people suffering from the worst form of the disease.
The team carried out experiments with peptidyl arginine deiminase 4 (PAD4), an enzyme believed to trigger RA. The researchers established that the blood of most patients suffering from severe forms of RA contained unique antibodies associated with the enzyme. While antibodies are a crucial component of the immune system, this particular subset appears to promote the disease as it increases the activity of the PAD4 enzyme.
After an assessment of patient records as part of their two-year study, the researchers found that 80% of subjects with these antibodies in their blood had seen their condition deteriorate over the course of one year. This compares to only 53% among RA patients whose blood was free of the antibodies. In addition, patients without the antibodies were likely to have the disease in much milder forms compared to those whose blood contained the enzyme-activating proteins. The laboratory tests showed that the antibodies increased PAD4 activity by 500 times, indicating that their presence could be responsible for the development of severe RA.
Dr Antony Rosen, senior study investigator, noted that the discovery could lead to early identification of patients with severe RA, resulting in significant health benefits for them. They could immediately begin aggressive drug treatment and find the most effective therapy for their condition, he explained.