Complement levels for cases with intermediate AMD versus controls
| Complement factors Median (IQR) | Intermediate AMD (n=109) | Controls (n=65) | OR (95% CI)* | P value† |
| C1q (µg/mL) | 77 (68–90) | 90 (82–96) | 0.96 (0.94 to 0.98) | <0.01 |
| C4 (µg/mL) | 107 (98–118) | 113 (99–127) | 0.99 (0.97 to 1.00) | 0.16 |
| C2 (µg/mL) | 4.5 (3.5–5.5) | 3.5 (2.5–4.6) | 1.29 (1.07 to 1.59) | 0.02 |
| MBL (ng/mL) | 784 (295–1269) | 522 (296–1239) | 1.00‡ (1.00 to 1.01) | 0.49 |
| C4b (µg/mL) | 10 (9–12) | 11 (9–12) | 0.91 (0.79 to 1.03) | 0.16 |
| C3 (µg/mL) | 78 (66–92) | 70 (53–81) | 1.01 (1.00 to 1.02) | 0.16 |
| Factor B (µg/mL) | 111 (100–127) | 125 (108–137) | 0.98 (0.96 to 0.99) | 0.01 |
| Factor D (µg/mL) | 1.7 (1.4–2.2) | 1.8 (1.5–2.1) | 1.04 (0.86 to 1.32) | 0.69 |
| Properdin (µg/mL) | 19 (18–23) | 19 (16–22) | 1.11 (1.01 to 1.24) | 0.05 |
| C3a (ng/mL) | 61 (50–76) | 50 (41–62) | 1.03 (1.01 to 1.05) | 0.01 |
| iC3b/C3b (ng/mL) | 654 (561–834) | 882 (657–1119) | 0.97‡ (0.95 to 0.98) | <0.01 |
| Ba (ng/mL) | 722 (617–876) | 597 (522–709) | 1.03‡ (1.01 to 1.05) | <0.01 |
| Factor H (µg/mL) | 198 (177–226) | 221 (195–251) | 0.99 (0.98 to 0.99) | 0.01 |
| Factor I (µg/mL) | 26 (22–29) | 31 (28–34) | 0.83 (0.77 to 0.89) | <0.01 |
| C5 (µg/mL) | 39 (34–44) | 45 (40–49) | 0.94 (0.90 to 0.98) | 0.01 |
| C5a (pg/mL) | 703 (575–793) | 564 (448–692) | 1.04‡ (1.02 to 1.07) | <0.01 |
| SC5b-9 (ng/mL) | 181 (158–213) | 164 (144–197) | 1.06‡ (0.99 to 1.15) | 0.16 |
*OR from the multivariable logistic regression with 95% CI after adjusting for age and family history of AMD.
†P values obtained from multivariate logistic regression including age and family history of AMD and adjusted for multiple comparisons using FDR.
‡OR corresponding to change in 10 units of complement factor.
AMD, age-related macular degeneration; FDR, false discovery rate.