Complement work-up performed in 5 patients with COVID 19-associated renal TMA
| Pt . | Time from COVID-19 diagnosis (d) . | Time from TMA diagnosis (d) . | C3 (mg/L) . | C4 (mg/L) . | sC5b-9 (ng/mL) . | FH (%) . | FI (%) . | CD46 (MFI) . | Anti-FH Ab (AU) . | CFHR1-CFHR3 copy number . | Complement genetics . | Complement gene variant classification . |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 13 | 3 | 840 | 301 | 761 | 70 | 100 | 12.3 | Negative | 1 | CFH c.2266T>A p.Ser756Thr | Pathogenic (reduced FH plasma level) |
| 2 | 13 | 1 | 1750 | 332 | 248 | 144 | 147 | ND | Negative | 1 | C3 c.463A>C p.Lys155Gln | Pathogenic (confers resistance to cofactor activity)12 |
| 54 | 42 | 1040 | 187 | 322 | 109 | 130 | 17 | Negative | ||||
| 3 | 34 | 3 | 1320 | 415 | 303 | 91 | 66 | 10.3 | Negative (sample collected after PE) | 0 | CFI c.1246A>C p.Ile416Leu | Pathogenic (reduced FI plasma level ; Not detected in supernatants and around 25% expression of WT in lysates)11 |
| 108 | 77 | 1160 | 461 | 1094* | 94 | 86 | 13.8 | Positive (4130) | ||||
| 167 | 136 | 1050 | 357 | 570 | 112 | 66 | ND | Positive (686) | ||||
| 4 | 19 | 19 | 1220 | 454 | ND | ND | ND | ND | Positive (1554) | 2 | CFH homozygous tgtgt haplotype | aHUS at-risk haplotype |
| 42 | 42 | 1470 | 507 | 345 | 130 | 161 | ND | Positive (1171) | ||||
| 122 | 122 | 1210 | 430 | ND | ND | ND | ND | Positive (516) | ||||
| 5 | 0 | 0 | 1270 | 550 | 136 | 120 | 120 | ND | Negative | ND | ND | ND |
| Pt . | Time from COVID-19 diagnosis (d) . | Time from TMA diagnosis (d) . | C3 (mg/L) . | C4 (mg/L) . | sC5b-9 (ng/mL) . | FH (%) . | FI (%) . | CD46 (MFI) . | Anti-FH Ab (AU) . | CFHR1-CFHR3 copy number . | Complement genetics . | Complement gene variant classification . |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 13 | 3 | 840 | 301 | 761 | 70 | 100 | 12.3 | Negative | 1 | CFH c.2266T>A p.Ser756Thr | Pathogenic (reduced FH plasma level) |
| 2 | 13 | 1 | 1750 | 332 | 248 | 144 | 147 | ND | Negative | 1 | C3 c.463A>C p.Lys155Gln | Pathogenic (confers resistance to cofactor activity)12 |
| 54 | 42 | 1040 | 187 | 322 | 109 | 130 | 17 | Negative | ||||
| 3 | 34 | 3 | 1320 | 415 | 303 | 91 | 66 | 10.3 | Negative (sample collected after PE) | 0 | CFI c.1246A>C p.Ile416Leu | Pathogenic (reduced FI plasma level ; Not detected in supernatants and around 25% expression of WT in lysates)11 |
| 108 | 77 | 1160 | 461 | 1094* | 94 | 86 | 13.8 | Positive (4130) | ||||
| 167 | 136 | 1050 | 357 | 570 | 112 | 66 | ND | Positive (686) | ||||
| 4 | 19 | 19 | 1220 | 454 | ND | ND | ND | ND | Positive (1554) | 2 | CFH homozygous tgtgt haplotype | aHUS at-risk haplotype |
| 42 | 42 | 1470 | 507 | 345 | 130 | 161 | ND | Positive (1171) | ||||
| 122 | 122 | 1210 | 430 | ND | ND | ND | ND | Positive (516) | ||||
| 5 | 0 | 0 | 1270 | 550 | 136 | 120 | 120 | ND | Negative | ND | ND | ND |
Normal range: C3: 615-1250 mg/L; C4: 93-380 mg/L; FH 70%-130%; FI 70%-130%; CD46: 13-19 MFI; sC5b9: <300 ng/mL.
CFH, complement factor H gene; CFHR, complement factor H-related protein; CFI, complement factor I; MFI, mean fluorescence intensity; ND, not determined; PE, plasma exchange.
The patient had several complications related to a perirenal hematoma that occurred after kidney biopsy.