aCL, anticardiolipin; ANA, antinuclear antibody; GOR, grade of recommendation; LA, lupus anticoagulant; LOE, level of evidence; SOA, strength of agreement.
a If there is clinical suspicion of lupus, blood tests (including serological marker tests) should be checked (LOE 2++, GOR B, SOA 98%).
b A positive ANA test occurs in 5% of the adult population and as such is of little use without symptoms. ANAs are present in 95% of patients with SLE.
c Anti-Ro/La and anti-RNP antibodies are less specific markers of SLE (2+/C), as they are found in other autoimmune rheumatic disorders as well as SLE (2+/C) (SOA 95%).
d Confirmatory tests for antiphospholipid syndrome are positive LA, aCL (IgG, IgM), and/or anti-beta-2 glycoprotein-1 (IgG, IgM) on 2 occasions at least 12 weeks apart (2++/B) (SOA 97%).