Zenodo
Antibodies against citrullinated proteins in patients with early rheumatoid arthritis: Relevance of likelihood ratios
By *Dr. Ulises Mercado, MD, MSc.
Abstract
Background
Antibodies against citrullinated proteins (ACPA) and rheumatoid factor (RF) are part of the classification criteria for the diagnosis of rheumatoid arthritis (RA) and are useful in the diagnosis and prognosis of RA.
Objective
To measure serum ACPA and RF levels in patients with early RA (up to 12 months)—including very early RA (<3 months)—who had not received treatment with disease-modifying antirheumatic drugs. Ninety patients with other autoimmune rheumatic diseases served as controls. Materials and Methods: There were 269 patients (226 women and 43 men) with a median age of 50 years seen at our hospital between 2012 and 2022. ACPA levels were measured using chemiluminescence (cut-off >17 U/mL) and RF levels were primarily measured using latex agglutination tests (cut-off ≥160). Sensitivity, specificity, likelihood ratios (LRs) and CI95% were calculated.
