Abstract / Summary
Background: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic microangiopathy. The global incidence of immune-mediated TTP (iTTP) is 1-6 cases per million people per year. The new (S3-level) clinical practice guideline is the first in the German-speaking world to compile evidence- and consensus-based recommendations on the diagnosis, treatment, follow-up management, and care of patients with immune-mediated thrombotic thrombocytopenic purpura (iTTP) and congenital thrombotic thrombocytopenic purpura (cTTP).
Methods: This clinical practice guideline was developed under the aegis of the Society for Thrombosis and Hemostatsis Research (Gesellschaft für Thrombose- und Hämostaseforschung, GTH) according to the criteria for S3-level guidelines issued by the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). It is based on information from publications retrieved through systematic literature searches and a structured assessment of the evidence using the GRADE scheme (Grading of Recommendations, Assessment, Development, and Evaluation), with a formal consensus process.
Results: Early diagnosis of TTP is essential. Measurement of ADAMTS13 activity is the diagnostic gold standard. In case of clinical suspicion of acute iTTP, treatment with plasma exchange, corticosteroids, and caplacizumab should be initiated at once. In a randomized trial with an active control group, plasma exchange lowered mortality at the end of the first treatment cycle from 15.7% to 3.9%. In a cohort study, standard treatment with plasma exchange, corticosteroids, caplacizumab, and rituximab was associated with a mortality of 2.2%, compared to 12.2% in a historical control cohort. Further management consists of regular clinical follow-up, ADAMTS13 monitoring, and the detection and treatment of late sequelae. For pregnancy in female TTP patients, monitoring and recurrence prophylaxis are recommended.
Conclusion: The purpose of the clinical practice guideline is to improve the acute care and interdisciplinary management of TTP. Further research is needed on the use of recombinant ADAMTS13 and on the definition of uTTP (TTP in the absence of causative antibodies or genetic mutations).