Comparison of TTP registries
| . | French Registry3 . | United Kingdom TTP Registry12,13 . | Oklahoma Registry2 . | Harvard TMA Registry6 . | Australian TTP/TMA Registry7 . | Japanese Registry4 . |
|---|---|---|---|---|---|---|
| Geographic region | France | Southeast England | Oklahoma | Massachusetts | Australia | Japan |
| Number of patients | 772 | 292 | 78 | 68 | 57 | 186 |
| Study population | Adults with first episode of TMA. | Patients with immune-mediated or congenital TTP. Other TMAs excluded. | Patients with first episode of clinically suspected TTP referred for PEX. | Clinically suspected cases of TTP with severe ADAMTS13 deficiency. | Patients with TMA and severe ADAMTS13 deficiency. | First onset acquired idiopathic TTP with severe ADAMTS13 deficiency. |
| Threshold for severe ADAMTS13 deficiency | <10% | <10% | <10% | <10% | <10% | <5% |
| Incidence, per million per year | ND | 6 | 2.17 | ND | ND | ND |
| Female, % (female to male ratio) | 68 (2:1) | 68 (2:1) | 77 (3.3:1) | 74 (2.8:1) | ND (2.8:1) | 55 (1.2:1) |
| Median age at initial presentation | 43 (range, 18-82) | 46 (range, 11-88)* | 41 (range, 9-72) | 40 (IQR, 29-53) | 38 (ND)* | 54 (IQR, 37-65) |
| Ethnic groups | White, 88% | White, 53% | White, 62% | White, 63.6% | European, 42% | Japanese, 100% |
| Afro-Caribbean, 12% | Afro-Caribbean, 22% | Black, 36% | Black, 19.7% | Asian, 12%, Polynesian/Micronesian, 3% | ||
| Asian, 6% | Native American, 2% | Asian, 1.5% | African, 2% | |||
| Hispanic, 15.2% | Middle Eastern, 9% | |||||
| Unknown/mixed, 32% | ||||||
| Presence of predisposing conditions | 49% primary | 100% primary | 100% primary | 100% primary | 18% with history of autoimmune disease | 100% primary |
| 51% with associated clinical conditions | ||||||
| ADAMTS13 activity assays | FRETS-VWF73 and full-length VWF ELISA | FRETS-VWF73 | FRETS-VWF73 and immunoblotting | FRETS-VWF73 | ND | Chromogenic ELISA and VWF multimer assay |
| Inhibitor assay | ELISA IgG and functional inhibitor assay | ELISA IgG confirmed by mixing study | Functional inhibitor assay | Functional inhibitor assay | ND | Functional inhibitor assay |
| Inhibitor positive, % | 73 | 90 | 83 | 82 | 89 (8 of 9 patients who were tested) | 98 |
| Mortality rate with initial episode, % | ND | 11 (5% in relapse episodes) | 13 | 5 | ND | 16.1 |
| . | French Registry3 . | United Kingdom TTP Registry12,13 . | Oklahoma Registry2 . | Harvard TMA Registry6 . | Australian TTP/TMA Registry7 . | Japanese Registry4 . |
|---|---|---|---|---|---|---|
| Geographic region | France | Southeast England | Oklahoma | Massachusetts | Australia | Japan |
| Number of patients | 772 | 292 | 78 | 68 | 57 | 186 |
| Study population | Adults with first episode of TMA. | Patients with immune-mediated or congenital TTP. Other TMAs excluded. | Patients with first episode of clinically suspected TTP referred for PEX. | Clinically suspected cases of TTP with severe ADAMTS13 deficiency. | Patients with TMA and severe ADAMTS13 deficiency. | First onset acquired idiopathic TTP with severe ADAMTS13 deficiency. |
| Threshold for severe ADAMTS13 deficiency | <10% | <10% | <10% | <10% | <10% | <5% |
| Incidence, per million per year | ND | 6 | 2.17 | ND | ND | ND |
| Female, % (female to male ratio) | 68 (2:1) | 68 (2:1) | 77 (3.3:1) | 74 (2.8:1) | ND (2.8:1) | 55 (1.2:1) |
| Median age at initial presentation | 43 (range, 18-82) | 46 (range, 11-88)* | 41 (range, 9-72) | 40 (IQR, 29-53) | 38 (ND)* | 54 (IQR, 37-65) |
| Ethnic groups | White, 88% | White, 53% | White, 62% | White, 63.6% | European, 42% | Japanese, 100% |
| Afro-Caribbean, 12% | Afro-Caribbean, 22% | Black, 36% | Black, 19.7% | Asian, 12%, Polynesian/Micronesian, 3% | ||
| Asian, 6% | Native American, 2% | Asian, 1.5% | African, 2% | |||
| Hispanic, 15.2% | Middle Eastern, 9% | |||||
| Unknown/mixed, 32% | ||||||
| Presence of predisposing conditions | 49% primary | 100% primary | 100% primary | 100% primary | 18% with history of autoimmune disease | 100% primary |
| 51% with associated clinical conditions | ||||||
| ADAMTS13 activity assays | FRETS-VWF73 and full-length VWF ELISA | FRETS-VWF73 | FRETS-VWF73 and immunoblotting | FRETS-VWF73 | ND | Chromogenic ELISA and VWF multimer assay |
| Inhibitor assay | ELISA IgG and functional inhibitor assay | ELISA IgG confirmed by mixing study | Functional inhibitor assay | Functional inhibitor assay | ND | Functional inhibitor assay |
| Inhibitor positive, % | 73 | 90 | 83 | 82 | 89 (8 of 9 patients who were tested) | 98 |
| Mortality rate with initial episode, % | ND | 11 (5% in relapse episodes) | 13 | 5 | ND | 16.1 |
IQR, interquartile range; ND, not described.
These studies include initial episodes and relapses of TTP.