PB0328 - Outcomes of immune-mediated thrombotic thrombocytopenic purpura at a single center in Japan

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Akira Matsumoto, MD (he/him/his)

Physician
Department of Hematology, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan

Co-Author(s)

Yoshiyuki Ogawa, MD, PhD

Senior Assistant Professor
Department of Hematology, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
CN

Chiaki Naito

Physician
Department of Hematology, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
KY

Kunio Yanagisawa

Assistant Professor
Infection Control and Prevention Center, Gunma University Hospital
Maebashi, Gumma, Japan
NK

Nobuhiko Kobayashi

Assistant Professor
Department of Hematology, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
YM

Yuri Miyazawa

Associate Professor
Department of Hematology, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
HU

Hideki Uchiumi

Physician
Department of Hematology, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
AH

Ayako Hirakata

Physician
Department of Pediatrics, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
YK

Yasuko Kobayashi

Associate Professor
Department of Pediatrics, Gunma University Graduate School of Medicine, Maebashi, Japan
Maebashi, Gumma, Japan
MM

Masanori Matsumoto

Professor
Department of Blood Transfusion Medicine, Nara Medical University, Kashihara, Nara, Japan
Kashihara, Nara, Japan
HH

Hiroshi Handa

Associate Professor
Department of Hematology, Gunma University Graduate School of Medicine
Maebashi, Gumma, Japan

Background: Life-threatening immune-mediated thrombotic thrombocytopenic purpura (iTTP) is caused by autoantibodies against a von Willebrand factor-cleaving protease [a disintegrin-like and metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS13)]. Before the recent use of caplacizumab, anti-VWF antibody, patients with iTTP require an immediate plasma exchange (PEX) and immunosuppressive therapy to eradicate autoantibody. However, some patients become refractory to standard therapy with PEX and steroids. Therefore, the mortality of iTTP was ~ 20% before caplacizumab era.

Aims: To reveal the clinical results of TTP in our hospital.

Methods: We retrospectively analyzed 18 patients with iTTP (median age, 63 y; range, 11 - 87 y; male, n = 7) who were treated at Gunma University Hospital for 14 years from 2009 to 2022. Two cases were secondary iTTP, the underlying diseases were systemic lupus erythematosus and T-cell lymphoma.

Results: The ADAMTS13 activity was suppressed to < 5% in all patients (median, < 0.5%; range, < 0.5 - 1.7%) by ADAMTS13 inhibitor (median, 2.5 BU/mL; range, 0.6 – 7.4 BU/mL). Two cases (11.1%) died. One female patient died of sudden severe alveolar and gastrointestinal bleeding immediately after emergency hospitalization. One male patient with T-cell lymphoma died of gastrointestinal ischemia. Seventeen patients received PEX and immunosuppressive treatment with 1 mg/kg/day of prednisolone (PSL),and 14 received steroid pulse therapy (mPSL 1000 mg/body/day, 3 days). This initial therapeutic strategy transiently improved symptoms in the 17 patients, but 10 became refractory to PSL, and 9 received rituximab (375 mg/m2, weekly, 4 times in total). Only one patient received caplacizumab. All 16 patients achieved clinical remission and remained alive.

Conclusion(s): Rapid diagnosis and appropriate therapy including rituximab for refractory cases resulted in favorable outcomes for patients with iTTP.