Hereditary thrombotic thrombocytopenic purpura (hTTP) is a rare thrombotic microangiopathy characterized by severe congenital ADAMTS13 deficiency and recurring acute episodes causing morbidity and premature death. Information on the annual incidence and severity of acute episodes in patients with hTTP is largely lacking. This study reports prospective data on 87 patients from the Hereditary TTP Registry (clinicaltrials.gov #NCT01257269) for survival, frequency, and severity of acute episodes from enrollment until December 2019. The 87 patients, followed up for a median of 4.2 years (range, 0.01-15 years), had a median age at overt disease onset and at clinical diagnosis of 4.6 years and 18 years (range, 0.0-70 years for both), respectively. Forty-three patients received regular plasma prophylaxis, whereas 22 did not, and treatment changed over time or was unknown in the remaining 22. Forty-three patients experienced 131 acute episodes, of which 91 (69%) occurred in patients receiving regular prophylaxis. This resulted in an annual incidence of acute episodes of 0.36 (95% confidence interval [CI], 0.29-0.44) with regular plasma treatment and of 0.41 (95% CI, 0.30-0.56) without regular plasma treatment. More than one-third of acute episodes (n = 51) were documented in children <10 years of age at enrollment and were often triggered by infections. Their annual incidence of acute episodes was significantly higher than in patients aged >40 years (1.18 [95% CI, 0.88-1.55] vs 0.14 [95% CI, 0.08-0.23]). The prophylactic plasma infusion regimens used were insufficient to prevent acute episodes in many patients. Such regimens are burdensome, and caregivers, patients, and their guardians are reluctant to start regular plasma infusions, from which children particularly would benefit.

Blood Center University Hospital Ostrava Ostrava Czech Republic

Center for Thrombosis and Hemostasis University Medical Center Mainz Mainz Germany

CTU Bern University of Bern Bern Switzerland

Department for BioMedical Research and

Department of Biostatistics and Epidemiology College of Public Health University of Oklahoma Health Sciences Center Oklahoma City OK

Department of Blood Transfusion Medicine Nara Medical University Kashihara Japan

Department of Clinical and Molecular Medicine Faculty of Medicine and Health Sciences Norwegian University of Science and Technology Trondheim Norway

Department of Haemostasis Disorders and Internal Medicine Institute of Hematology and Transfusion Medicine Warsaw Poland

Department of Hematology and Central Hematology Laboratory Inselspital Bern University Hospital University of Bern Bern Switzerland

Department of Hematology St Olavs Hospital Trondheim University Hospital Trondheim Norway

Division of Hematology and Hemostasis Department of Medicine 1 Medical University of Vienna Vienna Austria

Division of Hematology and Oncology Medical College of Wisconsin Milwaukee WI

NRL for Hemostasis Institute of Hematology and Blood Transfusion Prague Czech Republic

Research Laboratory Department of Internal Medicine and Hematology and Research Group for Immunology and Hematology Eötvös Loránd Research Network and Semmelweis University Budapest Hungary; and

University Institute of Clinical Chemistry Inselspital Bern University Hospital Bern Switzerland

Blood. 2021 Jun 24;137(25):3469-3471. doi: 10.1182/blood.2021011265. PubMed

References provided by Crossref.org

Hereditary thrombotic thrombocytopenic purpura and COVID-19: Impacts of vaccination and infection in this rare disease

See more in PubMed

ClinicalTrials.gov
NCT01257269