Serum Anticarbamylated Protein Antibodies In Rheumatoid Arthritis Patients And Its Correlation With Disease Activity And Joint Damage

Abstract

Anti-carbamylated protein (anti-CarP) antibodies are present in patients with Rheumatoid arthritis (RA) and may present before disease onset.the aim of this study was to assess the serum level of anticarbamylated protein antibodies in Rheumatoid Arthritis patients and investigate its correlation with disease activity and joint damage. Methods: This cross-sectional study included 60 patients selected from Rheumatology Outpatient Clinic and Inpatient Department at Ain Shams University Hospital fulfilled the ACR/ EULAR classification criteria of RA and 20 apparently healthy age and sex matched volunteers. Demographic and clinical data, smoking status, and disease activity score were recorded. Laboratory tests included erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, anti-citrullinated protein antibodies, and anti-CarP antibody. Results : Regarding serological biomarkers, rheumatoid factor (RF) was positive in 88.3%, 71.6% of patients had positive anti-carbamylated antibodies, and 61.6% of R.A patients had positive anti-citrulinated protein antibodies (ACPA). The percentage of positive anti-CarP was higher than positive ACPA among RA patients showing positive RF (67.9%). the highest sensitivity and specificity of anticarbmylated antibodies with a cut off value of 11.0, this cut off has 92% sensitivity and 90% specificity, with LR positive of 9.2. Conclusion : Anti-CarP antibody is a useful biomarker for early detection of Rhumatoid arthritis.