Proposed criteria for the assessment of complement implication in the pathogenesis of types of TMA
| Criteria . | aHUS (%) . | Secondary HUS (%) . | Remarks . |
|---|---|---|---|
| Enrichment in rare (pathogenic) variants in complement genes (vs healthy individuals) | 30-60 | <5 | Does not exclude transient complement (over)activation |
| Biomarkers of systemic complement activation | Not fully established | Not available | Reliability of complement biomarkers not validated, even in aHUS |
| Response to complement (C5) blockade | Shown in prospective nonrandomized trials | Variable | Difficulty in defining response to C5 blockade. Confounding effects of trigger withdrawal, treatment of underlying disease/condition |
| Relapse rate | <1 | ||
| Reflects transient vs sustained complement activation/dysregulation | 23-64 (carriers of complement gene variants) |
| Criteria . | aHUS (%) . | Secondary HUS (%) . | Remarks . |
|---|---|---|---|
| Enrichment in rare (pathogenic) variants in complement genes (vs healthy individuals) | 30-60 | <5 | Does not exclude transient complement (over)activation |
| Biomarkers of systemic complement activation | Not fully established | Not available | Reliability of complement biomarkers not validated, even in aHUS |
| Response to complement (C5) blockade | Shown in prospective nonrandomized trials | Variable | Difficulty in defining response to C5 blockade. Confounding effects of trigger withdrawal, treatment of underlying disease/condition |
| Relapse rate | <1 | ||
| Reflects transient vs sustained complement activation/dysregulation | 23-64 (carriers of complement gene variants) |