Table 1.
Clinical characteristics of patients with C3G/IC-MPGN.
| C3GN (n = 41) | DDD (n = 12) | IC-MPGN (n = 67) | Total (n = 120) | Healthy control (n = 85) | p* | ||
|---|---|---|---|---|---|---|---|
| Sex % men | 22 (53.6) | 3 (25) | 43 (64.2) | 68 (56.6) | 39 (45.9) | 0.156 | |
| Age at diagnosis, years | 22 (15–38) | 22 (16–42) | 19 (11–41) | 22 (13–40) | 31 (25–36) | 0.06 | |
| Clinical data | |||||||
| Non-visible hematuria, present | 25 (61) | 8 (66.6) | 38 (56.7) | 71(61.2) | |||
| Visible hematuria, present | 9 (22) | 2 (16.6) | 12 (18) | 23 (19.8) | |||
| Nephrotic syndrome, present | 19 (46.3) | 9 (75) | 33 (29.3) | 61 (52.1) | |||
| Renal impairment, present | 14 (34.1) | 5 (41.6) | 26 (38.8) | 45 (38.4) | |||
| Renal failure, present | 5 (12.2) | 1 (8.3) | 6 (8.9) | 12 (10.2) | |||
| Trigger, present | 8 (19.5) | 3 (25) | 10 (15) | 21 (17.5) | |||
| Familiarity, present | 6 (14.6) | 0 (0) | 5 (7.5) | 11 (9.1) | |||
| Complement data | |||||||
| Serum C3, g/L | 0.68 (0.27–1.06) | 0.49 (0.25–0.87) | 0.7 (0.48–0.99) | 0.69 (0.3–1) | 1.2 (1.1–1.4) | <0.0001 | |
| Serum C4, g/L | 0.28 (0.2–0.39) | 0.21 (0.16–0.37) | 0.21 (0.12–0.25) | 0.22 (0.16–0.31) | 0.32 (0.27–0.37) | <0.0001 | |
| Classical pathway activity, CH50/ml | 38 (19–62) | 47 (23–57) | 46 (30–60) | 46 (26–60) | 64 (56–72) | <0.0001 | |
| Alternative pathway activity (Alt), % | 38 (1–78) | 4 (0.3–66)1 | 70 (13–95) | 58 (1–86) | 91 (77–104) | <0.0001 | |
| Decreased C3 | 21 (51.2) | 10 (83.8) | 37 (55.2) | 68 (56.6) | 0 (0) | <0.0001 | |
| Decreased C3 with normal C4 | 18 (43.9) | 10 (83.8) | 25 (37.3) | 53 (44.2) | 0 (0) | <0.0001 | |
| Serum FHR-5, mg/L | 1.8 (1.5–2.6) | 1.6 (1.4–2) | 1.8 (1.3–2.2) | 1.8 (1.4–2.3) | 2.1 (1.8–2.5) | 0.004 | |
| sC5b-9, ng/ml | 429 (277–809) | 453 (248–970) | 376 (248–658) | 407 (256–719) | |||
| Elevated sC5b-9 | 28 (75.6) | 7 (77.7) | 45 (75) | 80 (75.4) | |||
| C1q, mg/L | 108 (90–130) | 95 (83–107) | 101 (69–123) | 104 (83–123.75) | |||
| Factor H, mg/L | 528 (470–697) | 715 (589–903) | 495 (324–700) | 534 (381–715) | |||
| Factor I, % | 93 (79–112) | 87 (78–98) | 90 (74–110) | 91 (78–109) | |||
| Factor B, % | 90 (72–106) | 88 (69–124) | 91 (72–106) | 86 (67–103) | |||
| Factor D, µg/ml | 1.9 (0.7–4.4) | 2.8 (0.8–4) | 2.4 (0.95–3.6) | 2.31 (0.9–3.94) | |||
| C3a, ng/ml | 160 (70–259) | 221 (59–259) | 125 (86–183) | 132 (79–208) | |||
| Bb, µg/ml | 1.57 (1.12–2.6) | 1.7 (0.05–3.7) | 1.4 (0.9–2) | 1.49 (0.99–2.28) | |||
| C4d, ng/ml | 6.2 (2.9–8.8) | 6.1 (3.3–9.4) | 4.1 (3–8.8) | 5.19 (3.1–8.9) | |||
| C3NeF, present | 7 (17.1) | 5 (41.6) | 15 (22.4) | 27 (22.5) | |||
| C4NeF, present | 7 (17.5) | 1 (8.3) | 9 (13.4) | 17 (14.2) | |||
| anti-Factor H, present | 4 (10) | 0 (0) | 3 (4.5) | 7 (5.9) | |||
| anti-C1q, present | 5 (12.8) | 1 (8.3) | 9 (14.3) | 15 (13.4) | |||
| anti-C3, present | 2 (5.4) | 1 (8.3) | 2 (3) | 5 (4.3) | |||
| anti-Factor B, present | 3 (8.1) | 2 (16.6) | 2 (3) | 7 (6) | |||
| Positivity for >1 complement autoantibody+ | 7 (18.9) | 1 (10) | 8 (12.7) | 16 (15.1) | |||
| LPV carriers** | 7 (17.1) | 2 (16.6) | 13 (19.4) | 22 (19.8) | |||
Data presented are number (%) or median (interquartile range).
FHR-5, Factor H-related protein 5.
*Group comparisons were made with Mann–Whitney U test between “total” and “controls.”
**LPVs were detected in the following genes: CFH, CFI, CFB, C3, CD46, THBD.
+The analyzed autoantibodies: anti-Factor H, anti-C3, anti-Factor B, C3NeF, C4NeF
Reference ranges: C1q: 60–180 mg/L; C3: 0.9–1.8 g/L; C4: 0.15–0.55 g/L; CH50: 48–103 CH50/ml; Alt: 70%–105%; Bb: 0.49–1.42 μg/ml; C4d: 0.7–6.3 μg/ml; sC5b-9: 110–252 ng/ml; Factor D: 0.51–1.59 μg/ml; Factor H: 250–880 mg/L; Factor I: 70%–130%; Factor B: 70%–130%.
C3G, C3 glomerulopathy; DDD, dense deposit disease; IC-MPGN, immune complex-mediated membranoproliferative glomerulonephritis, LPV, likely pathogenic variation; C3GN, C3 glomerulonephritis.
p-values < 0.05 are shown in bold.