Fig. 3

A schematic of one possible algorithm for evaluation of an SLE diagnosis using existing and proposed technologies. A point of care (POC) test for antinuclear antibodies (ANA) might be used as an office screening tool in primary care. A positive result would prompt further screening by measuring ANA by indirect immunofluorescence (IIF); the SLE-key® rule-out test might be also used. Positivity for ANA and a “not-ruled out” result for the SLE-key® test would then suggest a need for further autoantibody profiling using an antigen-specific assay. A negative test result for ANA, even with a “ruled-out” result on the SLE-key® test, may require further evaluation depending on the clinical scenario. DFS70 testing might be used to further improve diagnostic accuracy. The blue box indicates testing that might be done in primary care, with other tests being done after rheumatology referral. Yellow boxes indicate tests in development or not widely available; green boxes indicate tests that are clinically available, at least in the USA. aCL anti-cardiolipin antibodies, DFS70 dense fine speckles 70, SARD systemic autoimmune rheumatic diseases