Table 2.
Complement analyses
| Complement assessment at diagnostic biopsy | Number tested | Percentage of cohort | Number | Percentage | Median (range) |
|---|---|---|---|---|---|
| Serum C3, g/l (NR 0.7–1.7) | 25 | 100 | 0.77 (0.10–1.91) | ||
| Low serum C3 | 25 | 100 | 11 | 44.0 | |
| Serum C4, g/l (NR 0.16–0.54) | 25 | 100 | 0.27 (0.14–0.4) | ||
| Low serum C4 | 25 | 100 | 1 | 4.0 | |
| CH-50, % | 22 | 88 | 81 (20–130) | ||
| CH-50 <50% | 22 | 88 | 6 | 27.3 | |
| AP-50 (%) | 22 | 88 | 84.0 (20–115) | ||
| AP-50 <50% | 22 | 88 | 9 | 40.9 | |
| Anti-C1q antibody | 10 | 40 | 4 | 40.0 | |
| Serum factor H, mg/l | 22 | 88 | 597 (286–800) | ||
| Serum factor I, mg/l | 22 | 88 | 49 (26–76) | ||
| C3 nephritic factor | 24 | 96 | 2 | 8.3 | |
| Anti-fH antibody | 22 | 88 | 1 | 4.5 | |
| Complement gene varianta | 12 | 48 | 4 | 33.3 |
fH, complement factor H; NR, normal range.
a
Heterozygous factor I mutation (n = 1, c.57719G>T, p.(Gly367STOP) variant of uncertain significance); heterozygous C3 mutation (n = 1, c.463A>C, p.(Lys155Gln) likely pathogenic C3 gene mutation); FHR5 nephropathy13 (n = 2, duplication of exons 2 to 3 of CFHR5 gene in heterozygosity).