Definition of acute hTTP episodes and grading system to assess their severity
| Acute hTTP episodes | A typical TTP episode,24 or an acute cerebrovascular or cardiovascular or other ischemic event; or a renal illness for which the patient requires and/or receives medical care in addition to regular prophylactic treatment (eg, with plasma infusions) |
| In addition, maternal pregnancy complications resulting in a premature termination of pregnancy by abortion or delivery after 10 wk and before 34 wk of gestation | |
| If laboratory assays are performed, they typically show: | |
| Thrombocytopenia | |
| Presence of schistocytes on peripheral blood smear | |
| Decreased hemoglobin or reduced hematocrit | |
| Decreased haptoglobin | |
| Increased lactate dehydrogenase | |
| Increased (indirect) bilirubin | |
| Increased reticulocyte count | |
| Mild episode = severity score 1 | Typical signs and symptoms: |
| Petechiae, ecchymoses/bruises, small hematomas | |
| Cephalgia, vertigo, nausea | |
| Fatigue, drowsiness, weakness, | |
| (Sub)-febrile temperatures, shivering | |
| Gastrointestinal symptoms (eg vomiting, abdominal discomfort, diarrhea) | |
| Microscopic hematuria or macroscopic hematuria | |
| Hemolytic jaundice | |
| Tachycardia, moderate dyspnea | |
| Moderate episode = severity score 2 | Typical signs and symptoms: |
| Transient ischemic attack | |
| Angina pectoris | |
| Cardiac arrhythmia | |
| Acute renal failure, not requiring renal replacement | |
| Pregnancy-associated TTP event with abortion <10th week of gestation | |
| Severe episode = severity score 3 | Typical signs and symptoms: |
| Ischemic stroke | |
| Coma, seizure, or impaired consciousness requiring airway-protective measures and ventilation | |
| Acute myocardial infarction | |
| Acute renal failure requiring renal replacement therapy | |
| Multiorgan failure | |
| Pregnancy with abortion ≥10th wk of gestation, or a premature delivery <34th wk of gestation (maternal indication) | |
| Fatal episode = severity score 4 | Fatal outcome of a typical TTP episode and/or death from a cerebrovascular or cardiovascular event, or death during pregnancy |
| Acute hTTP episodes | A typical TTP episode,24 or an acute cerebrovascular or cardiovascular or other ischemic event; or a renal illness for which the patient requires and/or receives medical care in addition to regular prophylactic treatment (eg, with plasma infusions) |
| In addition, maternal pregnancy complications resulting in a premature termination of pregnancy by abortion or delivery after 10 wk and before 34 wk of gestation | |
| If laboratory assays are performed, they typically show: | |
| Thrombocytopenia | |
| Presence of schistocytes on peripheral blood smear | |
| Decreased hemoglobin or reduced hematocrit | |
| Decreased haptoglobin | |
| Increased lactate dehydrogenase | |
| Increased (indirect) bilirubin | |
| Increased reticulocyte count | |
| Mild episode = severity score 1 | Typical signs and symptoms: |
| Petechiae, ecchymoses/bruises, small hematomas | |
| Cephalgia, vertigo, nausea | |
| Fatigue, drowsiness, weakness, | |
| (Sub)-febrile temperatures, shivering | |
| Gastrointestinal symptoms (eg vomiting, abdominal discomfort, diarrhea) | |
| Microscopic hematuria or macroscopic hematuria | |
| Hemolytic jaundice | |
| Tachycardia, moderate dyspnea | |
| Moderate episode = severity score 2 | Typical signs and symptoms: |
| Transient ischemic attack | |
| Angina pectoris | |
| Cardiac arrhythmia | |
| Acute renal failure, not requiring renal replacement | |
| Pregnancy-associated TTP event with abortion <10th week of gestation | |
| Severe episode = severity score 3 | Typical signs and symptoms: |
| Ischemic stroke | |
| Coma, seizure, or impaired consciousness requiring airway-protective measures and ventilation | |
| Acute myocardial infarction | |
| Acute renal failure requiring renal replacement therapy | |
| Multiorgan failure | |
| Pregnancy with abortion ≥10th wk of gestation, or a premature delivery <34th wk of gestation (maternal indication) | |
| Fatal episode = severity score 4 | Fatal outcome of a typical TTP episode and/or death from a cerebrovascular or cardiovascular event, or death during pregnancy |