Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening blood disorder characterized by the formation of blood clots in small blood vessels. It is caused by antibodies targeting the A disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13 (ADAMTS13), which plays a role in cleaving von Willebrand factor. Most patients with iTTP have autoantibodies against specific domains of the ADAMTS13 protein, particularly the cysteine-rich and spacer domains.
View Article and Find Full Text PDFClin Adv Hematol Oncol
November 2024
Rationale & Objective: Atypical hemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy (TMA) caused by complement dysregulation. Ravulizumab is a C5i approved for the treatment of aHUS. This analysis assessed long-term outcomes of ravulizumab in adults and pediatric patients with aHUS.
View Article and Find Full Text PDFIn the 100 years since Eli Moschcowitz reported the first case of thrombotic thrombocytopenic purpura (TTP), there has been remarkable awareness and progress in the diagnosis and management of this rare blood disorder. This progress initially was the result of careful clinical observations followed by well thought-out therapeutic interventions, with dual goals of both improving outcomes and discerning the pathophysiology of TTP. The discovery of the ADAMTS13 protease set in motion the efforts to more accurately define the specific etiologies of thrombotic microangiopathies (TMAs) based on objective, scientific data rather than clinical characterizations alone.
View Article and Find Full Text PDFBackground: Mortality due to immune-mediated thrombotic thrombocytopenic purpura (iTTP) remains significant. Predicting mortality risk may potentially help individualize treatment. The French Thrombotic Microangiopathy (TMA) Reference Score has not been externally validated in the United States.
View Article and Find Full Text PDFPlease visit https://bit.ly/AJHpodcast to complete the accredited learning activity and receive CME credit or NCPD contact hours. Because immune-mediated rare blood disorders are uncommon, healthcare providers often lack the knowledge and experience necessary to identify, diagnose, and treat them in accordance with best practices.
View Article and Find Full Text PDFAvatrombopag is a novel oral non-peptide thrombopoietin receptor agonist (TPO-RA) that was approved by the FDA as a second-line therapy for chronic immune thrombocytopenia (cITP). Avatrombopag has shown promising results in regards to efficacy and tolerability, but to our knowledge, there are no reports of thrombotic complications associated with avatrombopag. We present two patients with chronic ITP who suffered thromboembolic events shortly after starting treatment with avatrombopag.
View Article and Find Full Text PDFImmune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare hematologic disease caused by autoantibodies against ADAMTS-13 that trigger microangiopathic hemolytic anemia. Therapeutic plasma exchange and glucocorticoids have been the mainstay of treatment for the past 30 years. In 2019, caplacizumab was approved as an addition to this regimen for the acute treatment of iTTP.
View Article and Find Full Text PDFRavulizumab and eculizumab are complement C5 inhibitors approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Ravulizumab requires less frequent infusions than eculizumab, which may reduce treatment burden. This study investigated patients' treatment preferences and the impact of both treatments on patient and caregiver quality of life.
View Article and Find Full Text PDFThe impact of residual symptoms following recovery from immune-mediated thrombotic thrombocytopenic purpura (iTTP) on activities of daily living during remission is not routinely discussed or evaluated by hematologists. This study used qualitative methodology to understand 3 issues from the patient's perspective: the most important symptoms during remission, the impact of these symptoms on their daily activities, and the effectiveness of communication with hematologists. Oklahoma and Ohio patients participated in either focus groups or individual interviews.
View Article and Find Full Text PDFIntroduction: Caplacizumab demonstrated efficacy and safety in patients with immune-mediated thrombotic thrombocytopenic purpura (iTTP) in the phase 3 HERCULES trial. However, data on long-term outcomes following caplacizumab treatment are limited.
Objectives: The post-HERCULES trial (NCT02878603) evaluated long-term outcomes of patients with iTTP treated with caplacizumab in HERCULES and safety and efficacy of repeated caplacizumab use.
Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is characterized by recurring episodes of thrombotic microangiopathy, causing ischemic organ impairment. Black patients are overrepresented in iTTP cohorts in the United States, but racial disparities in iTTP outcome and response to therapy have not been studied. Using the United States Thrombotic Microangiopathies Consortium iTTP Registry, we evaluated the impact of race on mortality and relapse-free survival (RFS) in confirmed iTTP in the United States from 1995 to 2020.
View Article and Find Full Text PDFImmune-mediated thrombocytopenic purpura (iTTP) is a thrombotic microangiopathy characterized by an acquired ADAMTS13 deficiency as a result of the presence of an antibody inhibitor of ADAMTS13 leading to the formation of ultralarge von Willebrand multimers. Treatment of iTTP includes plasma exchange, high-dose glucocorticoids, rituximab, and, more recently, caplacizumab, to prevent the development of exacerbations. There is the risk of both relapse and long-term complications that include neurocognitive deficits and cardiovascular events that occur in patients in remission after recovery from an acute iTTP episode.
View Article and Find Full Text PDFRes Pract Thromb Haemost
January 2022
De novo and relapsed immune-mediated thrombotic thrombocytopenic purpura (iTTP) have been documented to have occurred following severe acute respiratory syndrome coronavirus 2 (COVID-19) vaccination. Here, we present a case of a 28-year-old woman who received the tozinameran (BNT162b2, Pfizer-BioNtech) vaccine for COVID-19 and experienced an iTTP relapse during longitudinal follow-up. She received the vaccine 30 months after her initial diagnosis, while she was in clinical remission.
View Article and Find Full Text PDFHematopoietic cell transplantation-associated thrombotic microangiopathy (TMA) is a complication associated with higher nonrelapse mortality (NRM) in patients who undergo allogeneic transplant (HCT). Current classification criteria are not generally agreed on or validated, and the presence of confounding factors after transplant contribute to underdiagnosis or delayed diagnosis of TMA. We studied risk factors, incidence, and biomarkers of TMA in 119 adult allogeneic HCT recipients.
View Article and Find Full Text PDFRavulizumab and eculizumab are approved terminal complement inhibitor treatments for atypical hemolytic uremic syndrome (aHUS). Ravulizumab was engineered from eculizumab to have an increased half-life allowing for reduced dosing frequency (8-weekly vs. 2-weekly).
View Article and Find Full Text PDFImmune-mediated thrombotic thrombocytopenic purpura (iTTP) survivors experience high rates of adverse health sequelae and increased mortality over long-term follow-up. We conducted this multicenter cohort study to evaluate long-term mortality and causes of death in iTTP survivors. Between 2003 and 2020, 222 patients were enrolled in the Ohio State University and Johns Hopkins TTP registries and followed for a median of 4.
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