Prior to the 1970s, thrombotic thrombocytopenic purpura (TTP) was usually fatal for patients. Since then, the introduction of therapeutic plasma exchange (TPE) and adjunctive therapies have defined a new standard of care for patients with immune-mediated TTP (iTTP) and hereditary/congenital TTP (cTTP).1 Despite these advances, the rarity of the disease means that high-quality data on TTP management to guide clinicians is still limited.2
In August 2020, a multidisciplinary guideline panel that was formed by the International Society on Thrombosis and Haemostasis (ISTH) published recommendations and good practice statements on the treatment of TTP in the Journal of Thrombosis and Haemostasis.2
The panel was led by X. Long Zheng, MD, PhD, of the University of Kansas Medical Center in Kansas City, as the clinical co-chair; Sara Vesely, PhD, of the University of Oklahoma Health Sciences Center in Oklahoma City, as the methods co-chair; and Flora Peyvandi, MD, PhD, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca’Granda Ospedale in Italy, as the scoping panel chair along with a methods team from McMasters University in Canada, and patient representatives.
“TTP is a rare disease, so not every clinician or even every hematologist gets to see a patient with TTP on a regular basis. Therefore, not everyone has experience in how to manage these patients, and both diagnosis and management seem to vary across centers and conditions,” Dr Zheng, the primary author of the publication, said in an interview. “Recently, many different treatments have become available; we want to make sure that everyone is aware of these new developments.”
The panel discussed 12 treatment questions on the populations, interventions, comparisons, and outcomes related to both iTTP and cTTP and used the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the evidence and formulate the recommendations.
“It was very patient centered,” said Dr Zheng. “We not only considered the availability of the data and outcomes but also the patient’s preferences and values, the resources that are needed, and the costs associated with each treatment strategy.”
The panel agreed on 11 recommendations based on all of the available evidence, ranging from very low to moderate certainty, for the effects of various treatment strategies, including suppressing inflammation, impeding platelet clumping, replacing ADAMTS13, and suppressing ADAMTS13 antibody production.
Overall, the panel issued 3 strong recommendations along with 7 conditional recommendations. Highlights include the following recommendations:
- Strong recommendation for the addition of corticosteroids to TPE for first episode and relapses of acute iTTP.
- Conditional recommendation for addition of rituximab and caplacizumab for first episode and relapses of acute iTTP.
- Conditional recommendation for rituximab outside of pregnancy and for prophylactic TPE during pregnancy for asymptomatic iTTP with low ADAMTS13.
- Strong recommendation for prophylactic plasma infusion during pregnancy for asymptomatic cTTP.
- Conditional recommendation for plasma infusion or a wait and watch approach outside of pregnancy.