Antibody profiles of patients with APS grouped by anti-β2GPI-DI IgG positivity
| Immunological profile | APS (n=169) | Anti-β2GPI-DI IgG positive (n=55) | Anti-β2GPI-DI IgG negative (n=114) | P value |
| ANA (n (%)) | 87 (51.8) | 36 (65.5) | 51 (45.1) | 0.01 |
| Low complement (n (%)) | 57 (34.1) | 21 (38.2) | 36 (32.1) | 0.44 |
| Coombs’ test (n (%)) | 45 (28.3) | 16 (30.8) | 29 (27.1) | 0.63 |
| LAC (n (%)) | 147 (87.0) | 55 (100.0) | 92 (80.7) | <0.001 |
| Anti-β2GPI IgG/M (n (%)) | 108 (63.9) | 55 (100.0) | 53 (46.5) | <0.001 |
| Anti-β2GPI IgG (n (%)) | 71 (42.0) | 55 (100.0) | 18 (15.8) | <0.001 |
| Anti-β2GPI IgM (n (%)) | 47 (27.8) | 10 (18.2) | 37 (32.5) | 0.05 |
| aCL IgG/M (n (%)) | 83 (49.1) | 53 (96.4) | 30 (26.3) | <0.001 |
| aCL IgG (n (%)) | 83 (49.1) | 53 (96.4) | 30 (26.3) | <0.001 |
| aCL IgM (n (%)) | 4 (2.4) | 3 (5.5) | 1 (0.9) | 0.15 |
| Single aPL positivity (n (%)) | 69 (40.8) | 0 (0.0) | 69 (60.5) | <0.001 |
| Isolated LAC | 48 (38.4) | 0 (0.0) | 48 (42.1) | <0.001 |
| Isolated anti-β2GPI IgG/M | 20 (11.8) | 0 (0.0) | 20 (17.5) | <0.001 |
| Isolated aCL IgG/M | 1 (0.6) | 0 (0.0) | 1 (0.9) | <0.001 |
| Double aPL positivity (n (%)) | 31 (18.3) | 2 (3.6) | 29 (25.4) | <0.001 |
| LAC−, anti-β2GPI IgG/M+, aCL IgG/M+ | 1 (0.6) | 0 (0.0) | 1 (0.9) | 0.38 |
| LAC+, anti-β2GPI IgG/M−, aCL IgG/M+ | 12 (7.1) | 0 (0.0) | 12 (10.5) | 0.01 |
| LAC+, anti-β2GPI IgG/M+, aCL IgG/M− | 18 (10.7) | 2 (3.6) | 16 (14.0) | 0.03 |
| Triple aPL positivity (n (%)) | 69 (40.8) | 53 (96.4) | 16 (14.0) | <0.001 |
| Triple positive IgG isotype | 68 (40.2) | 53 (96.4) | 15 (13.2) | <0.001 |
| Triple positive IgM isotype | 4 (2.4) | 3 (5.5) | 1 (0.9) | 0.08 |
χ2 test or Fisher’s exact test was used for comparison of categorical variables.
Single, double and triple refers to the positive numbers of the criteria aPLs, including aCL IgG/M, anti-β2GPI IgG/M antibodies and LAC.
aCL, anticardiolipin; Anti-β2GPI-DI, anti-β2GPI-domain I; aPL, antiphospholipid antibodies; LAC, lupus anticoagulant.