Table 1.
Main clinical data of 65 patients with TMA
| C-TMA | Normal complement regulation | P value | |
|---|---|---|---|
| Patients, n | 44 | 21 | |
| HUS International’s nomenclature,7n (%) | |||
| Primary aHUS | 13 (30) | 0 | 0.006 |
| Secondary aHUS | 31 (70) | 21 (100) | 0.006 |
| Hypertensive emergency | 18 | 12 | |
| Pregnancy | 8 | 0 | |
| TMA after kidney transplantation | 2 | 3 | |
| Postsurgical TMA | 2 | 1 | |
| Streptococcal HUS | 1 | 0 | |
| HELLP | 0 | 3 | |
| Drug-induced TMA | 0 | 2 | |
| Features at presentation | |||
| M/F, n | 19/25 | 12/9 | 0.4 |
| European, n (%) | 43 (98) | 16 (76) | 0.01 |
| Age, yr, mean ± SD | 36±18 | 42±13 | 0.1 |
| Creatinine, μmol/L, median (IQR) | 492 (314–804) | 485 (231–778) | 0.5 |
| Dialysis, n (%) | 27 (61) | 11 (52) | 0.6 |
| Hemolysis, n (%) | 25 (57) | 11 (52) | 0.8 |
| Systemic hemolysis, n (%) | 18 (41) | 8 (38) | 1.0 |
| Platelets, ×109/l, median (IQR) | 101 (44–228) | 95 (52–178) | 0.8 |
| LDH, U/l, median (IQR) | 842 (398–2103) | 762 (465–1222) | 0.6 |
| ADAMTS13 activity >10%, n/N | 31/31 | 17/17 | |
| Low C4, n/N | 5/39 | 0/18 | 0.2 |
| Low C3, n/N | 18/41 | 1/18 | 0.005 |
| Massive ex vivo C5b9 formation, n/N | 41/41 | 0/21 | <0.001 |
| Rare variant(s)/FHAA, n (%) | 20 (45) | 0 (0) | <0.001 |
| Pathogenic, n (%) | 17 (37) | 0 (0) | 0.006 |
| Combined variants, n | 2 | 0 | 1.0 |
| MCPggaac, n/N | 16/31 | 12/19 | 0.6 |
| Treatment | |||
| Plasma therapy, n (%) | 31 (70) | 7 (33) | 0.007 |
| Immunosuppression, n (%) | 12 (27) | 2 (10) | 0.1 |
| Eculizumab, n (%) | 19 (43) | 5 (26) | 0.2 |
| Days after diagnosis, median (range) | 6 (0–100) | 4 (2–37) | 0.8 |
| Doses, median (range) | 13 (2–70) | 4 (1–10) | 0.009 |
| Ongoing, n/N | 3/19 | 0/6 | 0.6 |
| Clinical outcome | |||
| Patients, n/N | 43/44 | 20/21 | |
| Follow-up, yr, median (IQR) | 2.0 (0.6–3.8) | 0.5 (0.3–2.4) | 0.002 |
| Renal response, n (%) | 24 (56) | 9 (45) | 0.6 |
| Complete remission, n | 15 | 4 | 0.4 |
| Partial remission, n | 9 | 5 | 0.8 |
| ESKD at 3 months, n (%) | 17 (40) | 7 (35) | 0.8 |
| ESKD at last follow-up, n (%) | 19 (44) | 8 (45) | 0.8 |
| Patients with TMA recurrence, n (%) | 11 (26) | 0 | 0.01 |
| Deceased at 3 months, n (%) | 1 (2) | 1 (5) | 0.5 |
| Deceased at last follow-up, n (%) | 3 (7) | 2 (10) | 0.6 |
ADAMTS13, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (also known as von Willebrand factor cleaving protease); aHUS, atypical hemolytic uremic syndrome; C-TMA, complement-mediated thrombotic microangiopathy; ESKD, end-stage kidney disease; F, female; FHAA, factor H autoantibodies; HELLP, hemolysis, elevated liver enzymes, low platelets; IQR, interquartile range; LDH, lactate dehydrogenase; M, male; MCPggaac, at-risk haplotype for C-TMA; TMA, thrombotic microangiopathy.