LAUSR

Antinuclear antibodies (ANAs) are helpful to support the diagnosis of ANA-associated systemic rheumatic diseases (AASRD). Pisetsky et al recently reported on the variability of ANA detection, with differences observed between assay platforms (indirect immunofluorescence (IIF) vs solid phase) and kits in patients with established systemic lupus erythematosus (SLE).1 Variation of ANA detection has also been shown for automated IIF systems.2 Initiatives to better understand the variability of ANA tests are needed.3 Pisetsky et al 1 also pointed out that ANA negativity occurs in established SLE, thereby complicating screening for patients for clinical trials.1 Yet, an Italian study reported a high sensitivity of ANA for established SLE.4 Testing for ANAs is complex and accurate interpretation of test results might be difficult. A task force of the European League Against Rheumatism (EULAR) has recently been installed that will address these issues in conjunction with other international committees.5 In this context and of particular interest is that new criteria for the classification of patients with SLE are being developed under the umbrellas of the EULAR and the American College of Rheumatology (ACR).6 In these criteria, a history of ANAs ≥1:80 by HEp-2 IIF will be the entry criterion (ie, must be present to be considered for classification as SLE).6 The ≥1:80 cut-off was chosen in order to ensure …