Antibodies to Carbamylated Proteins Provide Insight into Rheumatoid Arthritis

Detection of antibodies to carbamylated proteins (anti-CarP) is an important advance in the diagnosis of Rheumatoid Arthritis (RA).

A study published in 2012 by a team at Leiden University Medical Center (LUMC; Leiden, The Netherlands) in Proceedings of the National Academy of Sciences of the United States of America (PNAS) showed that Immunoglobulin G (IgG) and IgA antibodies recognizing carbamylated antigens were present in about 50% of RA patients. Anti-CarP antibodies recognize homocitrulline and are therefore distinct from anticitrullinated protein antibodies (ACPA), including anti-cyclic citrullinated peptide (anti-CCP), a biomarker commonly used to diagnose RA. Anti-CarP IgG and IgA were detected in 16% and 30% of ACPA negative RA patients respectively. Additionally, anti-CarP antibodies were shown to be predictive of a more severe course of disease as measured by radiological progression in ACPA negative RA patients.

LUMC and Inova (San Diego, CA, USA) have announced the completion of an exclusive, worldwide license agreement for technology developed at LUMC to detect antibodies to carbamylated proteins (anti-CarP). "The detection of autoantibodies in sera of RA patients has provided important insight into the processes that initiate and drive RA. Since anti-CarP antibodies can also be detected in a subgroup of patients for whom so far no serological markers were available we believe this may provide new insight into the pathogenesis of RA,"said Dr. Leendert Trouw, assistant professor at LUMC.

Prof. Tom Huizinga, head of the department of Rheumatology at LUMC added "With new treatment options at hand it is now possible to apply early and aggressive treatment. Understanding which patients would benefit most from such an intervention is important to maximize efficiency, and detection of anti-CarP antibodies may identify such patients."

The LUMC is part of the Dutch Federation of University Medical Centers (NFU). The NFU is a collaboration of the eight University Medical Centers of The Netherlands.

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Leiden University Medical Center
Inova