Clinical Information

Double-stranded DNA (dsDNA) antibodies are systemic lupus erythematosus (SLE)-specific antibodies and are part of the immunology domain of the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria for SLE (1) as well as a previous guidance on SLE diagnosis.(2) The Crithidia luciliae indirect immunofluorescence test (CLIFT) is widely used as a confirmatory test following a positive dsDNA IgG result obtained by a solid-phase immunoassay due to its structural or analytical specificity.(3-5)

The CLIFT (dsDNA) test is indicated in patients who are positive for anti-cellular antibody (also known as antinuclear antibody [ANA]) homogeneous pattern (6) using HEp-2 substrate by indirect immunofluorescence assay (IFA) following a positive result for dsDNA IgG using a solid-phase immunoassay (eg, enzyme-linked immunosorbent assay or multiplex bead assay).(3,4) A positive CLIFT result is usually associated with the presence of moderate-to-high affinity dsDNA IgG antibodies. The CLIFT result may be negative and the immunoassay positive for dsDNA IgG in SLE patients with inactive (remission) disease or in patients with early disease.(3,4,7) Discordant results between CLIFT and solid-phase immunoassays may also be due to differences in the structural specificities of DNA analytes as well as the absence reliable reagents to harmonize available clinical tests.(3,5,8)

A minority of SLE patients may test negative using HEp-2 by IFA for nuclear antibodies.(9) Testing antibodies associated with the HEp-2 IFA cytoplasmic pattern such as ribosomal P IgG autoantibodies may be useful if features of neuropsychiatric disease are present.(9) Alternatively, patients may be tested for Smith, ribonuclear protein (RNP), SSA-52 and SSA-60 antibodies.(6,9)