Use

This panel can be helpful in the diagnosis of autoimmune diseases with a focus on rheumatoid arthritis (RA) by simultaneously testing for antinuclear antibodies (ANAs) with an immunofluorescence assay (IFA), performed on human epithelial type 2 (HEp‑2) cells, as well as the RA markers rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody (IgG). For specimens with positive ANA IFA results, reflex testing for ANA titer and pattern is performed. The laboratory evaluation for individuals with clinical suspicion of autoimmune diseases often begins with an ANA screen. The classic ANA IFA on HEp‑2 cells is considered by the American College of Rheumatology (ACR) as the current gold standard because of its overall high sensitivity for several autoimmune diseases. Although RA is not generally associated with ANA, occasional patients may present with features of RA and SLE ("rhupus") and be positive for ANA and RA markers. This panel includes RF and CCP IgG antibody, two widely used laboratory markers that are included in the ACR/European League Against Rheumatism classification (EULAR) criteria for RA. The combination of RF and CCP antibody provides greater sensitivity than either assay alone. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.