Table 1.
Summary of the main findings of studies on positive antiphospholipid antibodies in COVID-19
| Ref. (country) | Cases (% male) | Age, years | aPL + (any) | aCL + IgM | aCL + IgG | aβ2GPI + IgM | aβ2GPI + IgG | LA + | Non-criteria aPL + |
|---|---|---|---|---|---|---|---|---|---|
| 5 (Spain) | 24 (58) | 64 ± 14 | 8% | 8.3% | 0 | 8.3% | 0 | – | – |
| 6 (France) | 25 (68) | 47 (35–64) | 96% | 52% | 48% | 0 | 4% | 92% | aCL IgA=28% aβ2GPI IgA=12% aPL IgM=56% aPL IgG=60% |
| 8 (France) | 56 (–) | – | ~50% | 10% of patients had aCL or aβ2GPI IgG/IgM, no disaggregated information is reported. | 45% | – | |||
| 9 (Mexico) | 21 (43) | m 62 (54–67) | 57% | 14% | 10% | 0 | 5% | – | aPT IgM=5% aPS IgM=14% aPS IgG=10% aAnnV IgM=19% aAnnV IgG=5% |
| 10 (USA) | 172 (–) | – | 52% | 23% | 4.7% | 5.2% | 2.9% | – | aCL IgA=3.5% aβ2GPI IgA=4.1% aPS/aPT IgM=18% aPS/aPT IgG=24% |
| 11 (China) | 79 (57) | 60 | 47% | 2.5% | 5% | 1.2% | 15.1% | 2.5% | aCL IgA=21.5% aβ2GPI IgA=24% aPS/aPT IgM=8.8% aPS/aPT IgG=0% |
| 12 (China) | 19 (53) | m 65 (60–70) | 52% | 5.2% | 10.5% | 0 | 31.5% | 5.2% | aCL IgA=31.5% aβ2GPI IgA=36.8% |
| 13 (Belgium) | 31 (90) | m 63 (38–82) | 74% | 3% | 19% | 3% | 9.6% | 67.7% | aCL IgA=9.6% aβ2GPI IgA=9.6% aPS/aPT IgG=6.4% aPS/aPT IgM=12.9% |
| 14 (Italy) | 122 (51) | 54 ± 19 | ~50% | 2.7% | 13.4% | 7.1% | 6.3% | 22.2% | aCL IgA=1.7% aβ2GPI IgM=3.3% |
| 16 (France) | 150 (81) | m 63 (53–71) | – | – | – | – | – | 87.4% | – |
| 17 (Spain) | 27 (44) | 58 (20–90) | 25% | 0 | 0 | 0 | 0 | 22.2% | aβ2GPI IgA=3.7% |
| 18 (France) | 89 (68) | m 68 (63–71) | 72% | 2.2% | 5.6% | 2.2% | 5.6% | 66.3% | – |
| 19 (UK) | 35 (69) | 56 (18–83) | 91% | – | – | – | – | 91% | – |
| 20 (USA) | 68 (50) | ~56 | 44% | 1.4% | 0 | 1.4% | 0 | 44% | – |
| 21 (China) | 86 (62) | 66 ± 11 | 37% | – | – | – | – | – | – |
| 23 (Italy) | 33 (51) | m 70 (22–90) | 24% | 15% | 9% | 6% | 6% | – | – |
| 24 (Italy) | 122 (63) | 68 ± 16 | – | 6.6% | 5.7% | 9% | 15.6% | – | aPS/aPT IgG=2.5% aPS/aPT IgM=9.8% aβ2GPI IgA =6.6% |
| 25 (France) | 74 (–) | m ~64 | 88% | 12% (any aCL or aβ2GPI in IgM/IgG isotypes) | 85% | – | |||
| Total | 1233 (60) | – | ~54% | ~10.4% | ~10% | ~3.3% | ~7.8% | ~52.5% | – |
Age is presented as mean ± standard deviation unless otherwise specified; m denotes median (interquartile range)
aPL, antiphospholipid antibodies; aCL, anticardiolipin antibodies; aβ2GPI, anti-β2 glycoprotein-I antibodies; LA, lupus anticoagulant; aPT, anti-prothrombin antibodies; aPS, anti-phosphatidylserine antibodies; aAnnV, anti-annexin V antibodies