New 2019 SLE EULAR/ACR classification criteria are valid for identifying patients with SLE among patients admitted for pericardial effusion

The new 2019 SLE European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) have been recently published.1 Seritis is a prominent—often inaugural—feature of active SLE. Low titers of antinuclear antibodies (ANA) have been frequently reported in patients with idiopathic pericarditis.2 3 Of note, ANA positivity at a titer ≥1/80 is now mandatory as an entry criterion in the 2019 SLE EULAR/ACR classification criteria. Although classification criteria have theoretically no individual diagnostic purpose, we aimed at testing this new criteria set in unselected patients with pericardial effusion. In a retrospective study performed in the Department of Internal Medicine, University Paris Diderot, a French competence centre for rare systemic autoimmune diseases (AIDs), all consecutive adult patients hospitalised from January 2009 to January 2019 for pericardial effusion were reviewed. Clinical and biological data …