ANTIBODIES AGAINST ADVANCED GLYCATION END-PRODUCTS (ANTI-AGE) DISTINGUISH PATIENTS WITH A MORE INFLAMMATORY PROFILE AND WORSE OUTCOME IN SERONEGATIVE RHEUMATOID ARTHRITIS
Authors: T. J. van Wesemael, et al
Roughly one third of rheumatoid arthritis (RA) patients are «seronegative», and have neither detectable ACPA or RF autoantibodies. Seronegative RA is a heterogeneous group, including both milder subgroups of RA and more difficult to treat subgroups of patients. These Dutch investigators explored the role of a novel group of autoantibodies targeting advanced glycation end-product (anti-AGE), instead of peptides.
46% of RA patients versus 30% of controls had anti-age antibodies. Interestingly, anti-AGE antibodies were found at a similar prevalence in otherwise seronegative RA patients. Anti-AGE antibodies were associated with inflammation and radiologic joint damage progression in seronegative and seropositive RA patients.
The glycosylation of proteins influences to a large proportion their function. It is not surprising that the immune system also develops auto-antibodies against modified glycation products. Anti-AGE antibodies do not react to a modified peptide, like for example a citrullinated protein, but to a modified glycosylation of a peptide, that may occur with oxidative stress. While these anti-AGE autoantibodies are not specific for RA, they may be useful to identify ‘seronegative’ RA patients with more severe disease outcomes..