ACR/EULAR (2023) APS classification criteria
| Entry criteria . | |||
|---|---|---|---|
| At least 1 documented clinical criteriona, listed hereafter (domains 1-6) | |||
| plus . | |||
| A positiveb LAC test or moderate-to-high titers of aCL or aβ2GPI [IgG or IgM]) within 3 years of the clinical criterion | |||
| ↓ | |||
| If absent, do not attempt to classify as APS; if present, apply additive criteria . | |||
| ↓ | |||
| Additive clinical and laboratory criteria . | |||
| Do not count a clinical criterion if there is an equally, or more likely explanation than APS.c | |||
| Within each domain, only count the highest weighted criterion toward the total score. | |||
| Clinical domains and criteria . | Weight . | Clinical domains and criteria . | Weight . |
| D1. Macrovascular (venous thromboembolism [VTE]) | D2. Macrovascular (arterial thrombosis [AT]) | ||
| VTE with high-risk VTE profiled,* | 1 | AT with high-risk CVD profiled,* | 2 |
| VTE without high-risk VTE profile | 3 | AT without high-risk CVD profile | 4 |
| D3. Microvascular* | D4. Obstetric* | ||
| Suspected, ≥1 of following: Livedo racemosa (exam) | 2 | ≥3 Consecutive (pre)embryonic loss(es) (at <10 wk) and/or fetal death(s) (at 10 wk, 0 d to 15 w, 6 d) | 1 |
| Livedoid vasculopathy lesions (exam) Acute/chronic aPL-nephropathy (clinical or laboratory test) | Fetal death (at 16 w, 0 d to 33 w, 6 d) in the absence of PrE with severe features or PI with severe features | 1 | |
| Pulmonary hemorrhage (symptoms and imaging) | PreE with severe features (at <34 wk, 0 d) or PI with severe features (at <34 w, 0 d) with/without fetal death | 3 | |
| Established, ≥1 of the following: | 5 | PreE with severe features (at <34 w, 0 d) and PI with severe features (<34 w, 0 d) with/without fetal death | 4 |
| Livedoid vasculopathy (pathology) | |||
| Acute/chronic aPL nephropathy (pathology) | |||
| Pulmonary hemorrhage (BAL or pathology) | |||
| Myocardial disease (imaging or pathology) | |||
| Adrenal hemorrhage (imaging or pathology) | |||
| D5. Cardiac valve* | D6. Hematology* | ||
| Thickening | 2 | Thrombocytopenia (lowest, 20-130 × 109/L) | 2 |
| Vegetation | 4 | ||
| Laboratory domains and criteria . | Weight . | Laboratory domains and criteria . | Weight . |
| D7. aPL test by coagulation-based functional assay (LAC test) | D8. aPL test by solid phase assay (aCL ELISA and/or aβ2GPI ELISA [persistent]) | ||
| Positive LAC (one time only) | 1 | Moderate-to-high-positive (IgM) (aCL and/or aβ2GPI) | 1 |
| Positive LAC (persistent) | 5 | Moderate positive (IgG) (aCL and/or aβ2GPI) | 4 |
| High-positive (IgG) (aCL or aβ2GPI) | 5 | ||
| High-positive (IgG) (aCL and aβ2GPI) | 7 | ||
| Total score | |||
| Classify as APS for research purposes if there are at least 3 points from clinical domains AND at least 3 points from laboratory domains | |||
| Entry criteria . | |||
|---|---|---|---|
| At least 1 documented clinical criteriona, listed hereafter (domains 1-6) | |||
| plus . | |||
| A positiveb LAC test or moderate-to-high titers of aCL or aβ2GPI [IgG or IgM]) within 3 years of the clinical criterion | |||
| ↓ | |||
| If absent, do not attempt to classify as APS; if present, apply additive criteria . | |||
| ↓ | |||
| Additive clinical and laboratory criteria . | |||
| Do not count a clinical criterion if there is an equally, or more likely explanation than APS.c | |||
| Within each domain, only count the highest weighted criterion toward the total score. | |||
| Clinical domains and criteria . | Weight . | Clinical domains and criteria . | Weight . |
| D1. Macrovascular (venous thromboembolism [VTE]) | D2. Macrovascular (arterial thrombosis [AT]) | ||
| VTE with high-risk VTE profiled,* | 1 | AT with high-risk CVD profiled,* | 2 |
| VTE without high-risk VTE profile | 3 | AT without high-risk CVD profile | 4 |
| D3. Microvascular* | D4. Obstetric* | ||
| Suspected, ≥1 of following: Livedo racemosa (exam) | 2 | ≥3 Consecutive (pre)embryonic loss(es) (at <10 wk) and/or fetal death(s) (at 10 wk, 0 d to 15 w, 6 d) | 1 |
| Livedoid vasculopathy lesions (exam) Acute/chronic aPL-nephropathy (clinical or laboratory test) | Fetal death (at 16 w, 0 d to 33 w, 6 d) in the absence of PrE with severe features or PI with severe features | 1 | |
| Pulmonary hemorrhage (symptoms and imaging) | PreE with severe features (at <34 wk, 0 d) or PI with severe features (at <34 w, 0 d) with/without fetal death | 3 | |
| Established, ≥1 of the following: | 5 | PreE with severe features (at <34 w, 0 d) and PI with severe features (<34 w, 0 d) with/without fetal death | 4 |
| Livedoid vasculopathy (pathology) | |||
| Acute/chronic aPL nephropathy (pathology) | |||
| Pulmonary hemorrhage (BAL or pathology) | |||
| Myocardial disease (imaging or pathology) | |||
| Adrenal hemorrhage (imaging or pathology) | |||
| D5. Cardiac valve* | D6. Hematology* | ||
| Thickening | 2 | Thrombocytopenia (lowest, 20-130 × 109/L) | 2 |
| Vegetation | 4 | ||
| Laboratory domains and criteria . | Weight . | Laboratory domains and criteria . | Weight . |
| D7. aPL test by coagulation-based functional assay (LAC test) | D8. aPL test by solid phase assay (aCL ELISA and/or aβ2GPI ELISA [persistent]) | ||
| Positive LAC (one time only) | 1 | Moderate-to-high-positive (IgM) (aCL and/or aβ2GPI) | 1 |
| Positive LAC (persistent) | 5 | Moderate positive (IgG) (aCL and/or aβ2GPI) | 4 |
| High-positive (IgG) (aCL or aβ2GPI) | 5 | ||
| High-positive (IgG) (aCL and aβ2GPI) | 7 | ||
| Total score | |||
| Classify as APS for research purposes if there are at least 3 points from clinical domains AND at least 3 points from laboratory domains | |||
ACR/EULAR (2023) APS classification criteria modified from Barbhaiya et al.3
aCL and aβ2GPI moderate (40-79 U) and high (≥80 U) thresholds should be determined based on standardized ELISA results, not based on other testing modalities such as new automated platforms with variations of the solid phase (eg, magnetic microparticles and microspheres) and various detection systems (e.g., chemiluminescent immunoassay, multiplex flow immunoassay, or flow cytometry).
For detailed definitions of the clinical criteria and documentation, readers are referred to the Table 1 of the 2023 ACR/EULAR APS classification criteria document.
LAC assay performed and interpreted based on the International Society of Thrombosis and Haemostasis guidelines.
For examples of other potential etiologies, readers are referred to Supplementary Section 4 of the 2023 ACR/EULAR APS classification criteria document.
For detailed definitions of high-risk CVD and VTE profiles, readers are referred to Table 2 of the 2023 ACR/EULAR APS classification criteria document.
Newly included or significantly changed clinical domain in the ACR/EULAR classification criteria.
aCL, anticardiolipin; aβ2GPI, anti-β2-glycoprotein-I antibodies; AT, arterial thrombosis; BAL, bronchoalveolar lavage; CVD, cardiovascular disease; ELISA, enzyme-linked immunosorbent assay; LAC, lupus anticoagulant; PrE, preeclampsia; PI, placental insufficiency.