Table 2.
Concentration and functional activity of complement proteins in patients with thrombotic APS and healthy controls.
| Parameter | Patients | aPL positive controls | SLE controls | Healthy controls | P |
|---|---|---|---|---|---|
| (n = 38) | (n = 14) | (n = 16) | (n = 52) | ||
| C3, mean ± SD mg/dL (range) |
97.7 ± 26.3 (58–156) |
108.8 ± 39 (61–202) |
77 ± 20 (27–106) |
113.4 ± 40.6 (61–305) |
0.35a, 0.05b, 0.04c |
| Low C3 (%)1 | 41.2 | 30.8 | 43.8 | 19.2 | 0.74a, 0.76b, 0.04c |
| C4, mean ± SD mg/dL (range) |
16.9 ± 8.5 (2–41) |
21 ± 7 (12–35) |
15 ± 6 (5–27) |
23.9 ± 9.6 (12.8–74.4) |
0.19a, 0.58b, 0.001c |
| Low C4 (%)2 | 63.9 | 38.5 | 56.3 | 17.3 | 0.14a, 0.77b, <0.01c |
| FB, mean ± SD mg/dL (range) |
33 ± 7.7 (14–46.1) |
31 ± 8 (21.9–47.1) |
28 ± 6 (23–34) |
31.0 ± 8.27 (20–63) |
0.83a, 0.45b, 0.28c |
| Low FB (%)3 | 3.33 | 0 | 0 | 0 | 0.54a, 0.83b, 0.37c |
| CH100, mean ± SD Units/mL (range) |
46.9 ± 17.9 (20–70) |
60 ± 27 (23–89) |
63 ± 24 (36–102) |
70.5 ± 31.5 (20–165) |
0.19a, 0.23b, 0.01c |
| Low CH100 (%)4 | 64.3 | 57.1 | 71.4 | 59.4 | 0.37a, 0.63b, 0.51c |
APS: antiphospholipid syndrome; aPL positive controls: aPL+ patients without APS clinical criteria; HC: healthy controls; FB: factor B; 1C3 normal range: 83–172 mg/dL; 2C4 normal range: 17–51 mg/dL; 3FB normal range: 19–50 mg/dL; 4CH100 normal range: >70 units/mL. aANOVA comparison of thrombotic APS with aPL+ controls, bANOVA comparison of thrombotic APS with SLE controls, and cANOVA comparison of thrombotic APS with healthy controls.