Percentage positive among SLE and FM by ANA status
| SLE | FM | |||||
|---|---|---|---|---|---|---|
| ANA− | ANA+ | All | ANA− | ANA+ | All | |
| Low complement C3/C4 | 7% (0% to 19%) | 27% (15% to 38%) | 23% (13% to 32%) | 2% (0% to 6%) | 0% (NA) | 1% (0% to 4%) |
| High CB-CAPs | 13% (0% to 31%) | 51% (38% to 64%) | 43% (32% to 54%) | 4% (0% to 9%) | 4% (0% to 12%) | 4% (0% to 8%) |
| Anti-dsDNA confirmed by IIF | 7% (0% to 19%) | 20% (10% to 30%) | 17% (9% to 26%) | 0% (NA) | 0% (NA) | 0% (NA) |
| CB-CAPs in MAAA | 14% (0% to 33%) | 73% (60% to 85%) | 60% (48% to 72%) | 0% (NA) | 0% (NA) | 0% (NA) |
ANA was determined using IIF and the cut-off for a positive test result was set as ≥1:40. CIs (95%) are provided. Low complement was defined as C3<81 mg/dL or C4<12.9 mg/dL; high CB-CAPs were defined as EC4d≥14 net MFI or BC4d≥60 net MFI.
ANA, antinuclear antibodies; CB-CAP, cell-bound complement activation product; dsDNA, double-stranded DNA; FM, fibromyalgia; IIF, indirect immunofluorescence; MAAA, multi-analyte assay with algorithm; MFI, mean fluorescence intensity; NA: not applicable; SLE, systemic lupus erythematosus.