Tests for Specific Antinuclear Immunology Review 412
Antibodies (ANA)
TESTS
Anti-dsDNA
Anti-Sm
Antihistone, anti-DNP,
anti-SS-A/Ro, anti–SS-B/La,
anti-nRNP
Extractable nuclear antigen
(ENA) antibiotics
COMMENTS
Most specific ab for SLE. Titers correlate with disease
activity. Peripheral or homogeneous fluorescent pat-
tern with indirect immunofluorescence (IIF). Other
methods: EIA, immunoblotting, immunodiffusion.
Coarsely speckled pattern with IIF. Other methods:
EIA, immunoblotting, immunodiffusion.
Generally not useful for Dx of SLE. Used to Dx
other connective tissue diseases. Methods: IIF, EIA,
immunoblotting, immunodiffusion.
Immunodiffusion (Ouchterlony double diffusion) test
panel that typically tests for abs to Sm, SS-A/Ro,
SS-B/La, RNP. Precipitin lines of identity/nonidentity.
New method: multiplex bead assay. Immunoassay
using specific ag-coated beads & flow cytometry to
detect multiple (currently 6–13) ANAs simultaneously.
SENSITIVITY
FOR SLE
Low
Low
Low
Low
SPECIFICITY FOR SLE
High. Uncommon in
other diseases or normal
individuals.
High. Uncommon in
other diseases or normal
individuals.
Low.
Anti-Sm is specific for
SLE.
