Abstract Number: OC 07.3
Meeting: ISTH 2020 Congress
Background: Follow-up data from the International Hereditary TTP Registry show a high incidence of acute events despite regular plasma prophylaxis in many hTTP patients.
Aims: We evaluated whether the events occurring under regular prophylaxis were less severe (e.g. only laboratory abnormalities), compared to events in patients not treated prophylactically.
Methods: We scored the severity of 109 acute survived events plus 4 acute lethal events (score 1-5, according to Falter et al.*, slightly modified, Table 1) in 87 hTTP patients and compared the severity of events occurring with or without prophylactic treatment (Table 2).
Results: Of 87 confirmed hTTP patients with prospective follow-up, 41 survived 109 acute events, with a median time between onset of symptoms to treatment of 0 days (range 0-4 days) and median duration to recovery of 4 days (range 0-43 days). Thus, 87/109 (80%) survived events were immediately recognized. 74/109 events occurred in 29 patients under prophylaxis, and 35/109 events in 16 patients not under prophylaxis. The severity of acute events occurring under prophylaxis versus those occurring in the absence of prophylaxis was not different (Table 2). Nevertheless, our data show that in some patients, the introduction of regular plasma prophylaxis after the occurrence of severe acute events was beneficial. In fact, three of our patients have not experienced any additional severe event(s) (e.g. strokes and transient ischemic attacks) since the introduction of regular prophylaxis. Contrarily, discontinuation of regular prophylaxis was followed by severe acute events (e.g. strokes, and even death) in two other patients.
Conclusions: Currently used plasma prophylaxis schedules are not sufficiently effective to prevent the occurrence of acute events in hTTP patients. Additional prospective follow-up and scoring of acute events will improve future treatment in hTTP.
|1 = laboratory abnormalities only||Some of these laboratory abnormalities: thrombocytopenia decreased hemoglobin, red blood cells or hematocrit decreased haptoglobin increased LDH increased bilirubin (indirect bilirubin) increased reticulocytes presence of schistocytes|
|2 = mild||Laboratory abnormalities plus at least one of the following clinical manifestations: petechiae or bleeding, hematomas, ecchymoses cephalgia, vertigo, nausea fatigue, drowsiness, weakness, (sub)-febrile temperatures, shivering gastrointestinal symptoms (vomiting, abdominal pain, diarrhea)|
|3 = moderate||Laboratory abnormalities plus at least one of the following clinical manifestations: micro- or macro-hematuria jaundice tachycardia, dyspnea reversible dys-or paresthesia, visual field defects, impaired consciousness (somnolence, stupor), disorientation|
|4 = severe||Laboratory abnormalities plus at least one of the following clinical manifestations: transient ischemic attack stroke with aphasia and/or paresia and or apraxia and/or ataxia acute myocardial infarction coma, seizure acute renal failure multi organ failure in case of pregnancy: abortion or still birth, premature delivery|
|5 = lethal||hTTP event with fatal outcome|
[Severity score for hTTP events, slightly modified from Falter et al. (Thromb Haemost 2018;118:1743-51)]
|Severity score||Events under Prophylaxis (n=76*)||Events not under Prophylaxis (n=37*)|
|1 = laboratory abnormalities only||11 (15%)||4 (11%)|
|2 = mild||46 (60%)||23 (62%)|
|3 = moderate||9 (12%)||2 (5.5%)|
|4 = severe||8 (10.5%)||6 (16%)|
|5 = lethal*||2 (2.5%)||2 (5.5%)|
|* sum of all survived acute events plus lethal events|
[Severity of acute events occurring while patients were under prophylactic treatment or not]
To cite this abstract in AMA style:Tarasco E, Bütikofer L, Sinkovits G, Prohászka Z, von Krogh AS, Knöbl PN, Friedman KD, George JN, Aebi-Huber I, Jalowiec KA, Cermakova Z, Górska-Kosicka M, Windyga J, Hrachovinova I, Largiadèr CR, Matsumoto M, Lämmle B, Kremer Hovinga JA. Severity of Acute Events in Patients with Hereditary Thrombotic Thrombocytopenic Purpura (hTTP) with or without Regular Plasma Prophylaxis: Results from the International Hereditary TTP Registry [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/severity-of-acute-events-in-patients-with-hereditary-thrombotic-thrombocytopenic-purpura-http-with-or-without-regular-plasma-prophylaxis-results-from-the-international-hereditary-ttp-registry/. Accessed November 30, 2021.
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