Table 2.
Clinical characteristics of patients with aPL positivity in the APS ACTION registry (2010–2019) who were tested for 3 aPL, categorized according to aPL profile (N = 660)*
| LAC only positivity, 168 (25) | Positivity for any single aPL (including LAC only)†, 215 (32) | Single aPL positivity (excluding LAC only), 47 (7) | Double aPL positivity†, 167 (25) | Triple aPL positivity†, 278 (42) | |
|---|---|---|---|---|---|
| Any vascular events | 127 (73) | 148 (67) | 21 (45) | 118 (68) | 195 (70) |
| Arterial thrombosis | 61 (36) | 73 (34) | 12 (26) | 68 (41) | 96 (35) |
| Venous thrombosis | 81 (48) | 92 (43) | 11 (23) | 66 (40) | 132 (47) |
| Microvascular thrombosis | 10 (6) | 12 (6) | 2 (4) | 9 (5) | 16 (6) |
| Transient ischemic attacks | 11 (7) | 13 (6) | 2 (4) | 19 (11) | 20 (7) |
| Any pregnancy morbidity | 43/84 (51) | 53/108 (49) | 10/24 (42) | 41/86 (48) | 62/117 (53) |
| >1 fetal death at 10 weeks of gestation or later | |||||
| 31 (51) | 39 (52) | 8 (57) | 29 (53) | 43 (56) | |
| >1 preterm delivery prior to 34 weeks of gestation | |||||
| 12 (20) | 13 (17) | 1 (7) | 14 (25) | 29 (38) | |
| ≥3 pre-embryonic/embryotic losses prior to 10 weeks of gestation | |||||
| 9 (15) | 14 (19) | 5 (36) | 6 (11) | 6 (8) | |
| Any other clinical manifestation | 93 (55) | 107 (50) | 14 (30) | 104 (62) | 158 (57) |
| Livedo reticularis/racemosa | 27 (16) | 28 (13) | 1 (2) | 24 (14) | 32 (12) |
| Persistent thrombocytopenia† | 26 (15) | 30 (14) | 4 (9) | 29 (17) | 70 (25) |
| Hemolytic anemia‡ | 9 (5) | 10 (5) | 1 (2) | 7 (4) | 16 (6) |
| Cardiac valve disease | 11/146 (8) | 12/188 (6) | 1/42 (2) | 12/142 (8) | 32/234 (14) |
| Skin ulcers | 6 (4) | 7 (3) | 1 (2) | 7 (4) | 10 (4) |
| aPL-associated nephropathy | 4/157 (3) | 4/201 (2) | 0 | 5/160 (3) | 11/256 (4) |
| Cognitive dysfunction | 14 (8) | 17 (8) | 3 (6) | 20 (12) | 33 (12) |
| Multipe sclerosis–like disease | 2 (1) | 3 (1) | 1 (2) | 3 (2) | 0 |
| Chorea | 2 (1) | 2 (1) | 0 | 4 (2) | 6 (2) |
| Seizure | 17 (10) | 21 (10) | 4 (9) | 13 (8) | 23 (8) |
| White matter lesions | 33/120 (28) | 40/155 (26) | 7/35 (20) | 33/116 (28) | 45/190 (24) |
Except where indicated otherwise, values are the number (%) of patients. Patients in this analysis were tested for three aPLs (LAC, aCL, and anti-β2GPI antibodies). An additional 8 patients were tested for these three aPLs but had low titers (20–39 units) on enzyme-linked immunosorbent assay with negative LAC test, and were thus excluded from the analysis. Single aPL positivity was defined as positivity on one of the three aPL tests for aPLs, double aPL positivity was defined as positivity on two of three tests, and triple aPL positivity was defined as positivity on all three tests. All groups except LAC only and single aPL positivity were mutually exclusive. Only 5 (0.8%) of 660 patients had isolated aCL/anti-β2GPI IgA positivity with negative results for LAC and aCL/anti-β2GPI IgG and IgM. In total, 6 patients had catastrophic APS, distributed between double aPL– and triple aPL–positive groups. aCL = anticardiolipin antibody; anti-β2GPI = anti–β2-glycoprotein I; aPL = antiphospholipid antibody; APS = antiphospholipid syndrome; APS ACTION = APS Alliance for Clinical Trials and International Networking; LAC = lupus anticoagulant.
Cutoff value for aCL positivity and anti-β2GPI IgG, IgM, and IgA positivity was defined as a patient having a titer of at least 40 units upon antibody testing.
Defined as a platelet count of <100,000 per microliter tested twice at least 12 weeks apart.
Defined as anemia in the presence of antibodies directed against red blood cells, evidenced by either direct or indirect Coombs’ tests.