Immunchemie und Immunpathologie

Clinical Utility of Anti-Carbamylated Protein Antibody as a New Marker in Seronegative Rheumatoid Arthritis

Abstract

El-Shorbagy MS, El-Saied AH, Essa KS and Awad MMA

Introduction: The development of rheumatoid arthritis (RA) is associated with the formation of a wide spectrum of autoantibodies, including rheumatoid factors (RFs) and anti-citrullinated protein antibodies (ACPAs). A family of autoantibodies that recognize carbamylated proteins, Anti-CarP antibodies can be detected in sera of RA patients. The aim of the present study was to evaluate the role of anticarbamylated protein antibody (Anti-CarP antibodies) in diagnosis of seronegative (Negative RF and Negative ACCP) RA patients, in monitoring the severity of inflammation and degree of associated joint damage.

Methodology: Our study included 60 patients with seronegative RA (4 males and 56 females), their ages ranged between 29 and 70 years with a mean age of 48.5 ± 11.8 years, and 20 healthy controls of matched age and sex. Anti-CarP antibodies concentrations were measured by enzyme-linked immune-sorbent assay (ELISA).

Results: ACarPA was statistically significant increase in RA group compared to control group with no statistical significant differences between different RA groups. There was no statistical correlation between ACarPA and inflammatory markers (CRP and ESR). ACarPA had high diagnostic performance in differentiating RA from control and mild RA from control. There was no statistically significant difference in ACarPA between cases with or without osteolytic lesions in various RA studied groups.

Conclusion: Serum Anti-CarP Ab is a significant serological marker in sero-negative RA patients that has the potential to differentiate RA patients from control group.