Race, rituximab, and relapse in TTP

• Type of Material: Article
• Authors: Shruti Chaturvedi, Johns Hopkins University; Ana G Antun, Emory University; Andrew M. Farland, Wake Forest University; Ryan Woods, Wake Forest University; Ara Metjian, University of Colorado, Denver; Yara A. Park, University of North Carolina at Chapel Hill; Gustaaf de Ridder, University of North Carolina at Chapel Hill; Briana Roberta Gibson, Emory University; Raj S. Kasthuri, University of North Carolina at Chapel Hill; Darla K. liles, East Carolina University; Frank Akwaa, University of Rochester; Todd Clover, St. Charles Healthcare; lisa Baumann Kreuziger, Medical College of Wisconsin; J. Evan Sadler, Washington University. St. Louis; Meera Sridharan, Mayo Clinic, Rochester; Ronald S. Go, Mayo Clinic, Rochester; Keith R. McCrae, Cleveland Clinic; Harsh Vardhan Upreti, Johns Hopkins Univeristy; Angela Liu, Johns Hopkins University; Ming Y. Lim, University of Utah; Radhika Gangaraju, University of Alabama at Birmingham; X. Long Zheng, University of Kansas; Jay S. Raval, University of New Mexico; Camila Masias, Baptist Health South Florida; Spero R. Cataland, The Ohio State University; Andrew Johnson, Department of Laboratory Medicine and Pathology; Elizabeth Davis, University of Minnesota; Michael D. Evans, University of Minnesota; Marshall A. Mazepa, University of Minnesota
• Language: English
• Date: 2022-07-09
• Publisher: Elsevier
• Publication Version: Final Published Version
• Copyright Statement: © 2019 Published by Elsevier Inc. on behalf of American Society of Hematology.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): https://doi.org/10.1182%2Fblood.2022016640
• Title of Journal or Parent Work: Blood
• Volume: 140
• Issue: 12
• Start Page: 1335
• End Page: 1344
• Grant/Funding Information: This study was supported by grants K99HL150594 (S.C.) and UL1TR001111 and UL1TR002494, the National Institutes of Health Clinical and Translational Science Awards to the University of North Carolina at Chapel Hill and the University of Minnesota, for data maintenance and security of the REDCap databases used to house the data for this study.
• Keywords: iTTP; racial disparities; relapse-free survival
• Research Categories: Health Sciences, Public Health

Abstract

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. We separately examined the impact of rituximab therapy and presentation with newly diagnosed (de novo) or relapsed iTTP on RFS by race. A total of 645 participants with 1308 iTTP episodes were available for analysis. Acute iTTP mortality did not differ by race. When all episodes of iTTP were included, Black race was associated with shorter RFS (hazard ratio [HR], 1.60; 95% CI, 1.16-2.21); the addition of rituximab to corticosteroids improved RFS in White (HR, 0.37; 95% CI, 0.18-0.73) but not Black patients (HR, 0.96; 95% CI, 0.71-1.31). In de novo iTTP, rituximab delayed relapse, but Black patients had shorter RFS than White patients, regardless of treatment. In relapsed iTTP, rituximab significantly improved RFS in White but not Black patients. Race affects overall relapse risk and response to rituximab in iTTP. Black patients may require closer monitoring, earlier retreatment, and alternative immunosuppression after rituximab treatment. How race, racism, and social determinants of health contribute to the disparity in relapse risk in iTTP deserves further study.