Lupus & antiphospholipid syndrome
Reference intervals for anticardiolipin (aCL) and anti-β2GPI immunoglobulin A, G and M (IgAGM) antibodies in a large health-inspection population: a foundational study for combined-isotype assay interpretation
Authors' conclusion
Assay-specific 99th-percentile reference intervals for aCL IgAGM and anti-β2GPI IgAGM were established in a large health-inspection population and a physiologically normal reference subgroup.
Study context
- Population
- Individuals undergoing health inspection (5170 male, 2676 female; age 15–90 years); retrospective systemic lupus erythematosus (SLE) and coronary heart disease (CHD) populations with historical IgAGM results
- Participants
- 7,846 vs 989
- Exposure
- Health-inspection population vs Physiologically normal reference subgroup
- Health-inspection populationn = 7,846
- Physiologically normal reference subgroupn = 989
- Outcome
- 99th-percentile reference intervals for aCL IgAGM and anti-β2GPI IgAGM (ELISA)
Methodological detailsreference interval study, 99th-percentile reference intervals, retrospective contextual analyses in SLE and CHD
- Reference interval study
- 99th-percentile reference intervals
- Retrospective contextual analyses in SLE and CHD
Main finding
As reported in the abstract
aCL IgAGM 99th percentile, all 7846 individuals
35.4 RU/mL
Anti-β2GPI IgAGM 99th percentile, all 7846 individuals
51.7 RU/mL
aCL IgAGM 99th percentile, physiologically normal reference subgroup
23.33 RU/mL
Anti-β2GPI IgAGM 99th percentile, physiologically normal reference subgroup
46.25 RU/mL
Observational data: associations, not effects.
Further findings
| Outcome | Estimate | P value |
|---|---|---|
| Anti-β2GPI above cut-off, SLE vs CHD (retrospective)SLE vs CHD | proportion above general health participant cut-off 11.4% vs 4.5% | P = 0.0425 |
| Anti-β2GPI above cut-off, SLE vs CHD (retrospective)SLE vs CHD | proportion above physiologically normal cut-off 12.3% vs 4.5% | P = 0.0200 |
Sex and age differences
- Sex differences significant for both antibodies in the overall population and in the physiologically normal subgroup
- aCL showed age-related increases at the upper tail
Anti-β2GPI above cut-off, SLE vs CHD (retrospective)
- SLE showed higher proportions above all four cut-offs than CHD
Exploratory: antibody levels and triglyceride-related profiles
- Antibody levels linked to triglyceride-related profiles
- Exploratory
Parts of this Brief are withheld: the automatic checks could not confirm them against the abstract.
Original publication
Composed by AI from the published abstract and checked against it. How Briefs are made →