A Case of Idiopathic Thrombotic Thrombocytopenia Purpura With Suspected Myositis

Document Type

Conference Proceeding

Publication Date

5-2026

Publication Title

American Journal of Respiratory and Critical Care Medicine

Abstract

Thrombotic thrombocytopenic purpura (TTP) is a disorder marked by microangiopathic hemolytic anemia, profound thrombocytopenia, and ischemic injury to end organs. TTP is caused by a severe deficiency of ADAMTS13, a specific protease responsible for cleaving von Willebrand factor (VWF). When ADAMTS13 activity is severely reduced (< 10%), the large uncleaved VWF multimers build up leading to platelet adhesion and aggregation. This leads to TTP characterized by widespread microthrombi and organ ischemia. TTP is a rare and life-threatening disorder. Rapid recognition is paramount as untreated TTP has a mortality rate around 90%. First-line treatment for TTP involves daily therapeutic plasma exchange to replenish deficient ADAMTS13 and corticosteroids for immunosuppression. Rituximab, a humanized anti-CD20 monoclonal antibody, is commonly added to target ADAMTS13 autoantibodies. We present an interesting case of TTP. A 40 year old female presented for evaluation of bilateral joint pain involving the fingers, wrists, knees, ankles and painless, nonpruritic skin discoloration of the palms and soles, as well as occasional bleeding of her gums when brushing teeth for the past month. Onset of symptoms were followed by a viral illness in which she was told she had influenza but was not formally diagnosed. On admission, platelets were found to be 17,000 with bite cells and schistocytes seen on peripheral smear. Haptoglobin was < 8 mg/dL and LDH was 803 U/L. Due to concern for TTP, she was started on plasmapheresis, corticosteroids, and Rituximab. Further workup of the joint pain revealed creatine kinase elevated at 882 U/L, AST 252 U/L, ALT 134 U/ L, and Jo-1 Antibody, IgG positive. ADAMTS13 Activity resulted 2 days later and was < 5%. Platelet count improved with treatment and repeat ADAMTS13 was within normal limits. She was transitioned to oral prednisone for a suspected myositis with improvement in joint pain, creatine kinase, AST, ALT levels. This case illustrates an interesting presentation of TTP with suspected myositis.

Volume

212

Issue

S1

First Page

S3848

Comments

American Thoracic Society International Conference, May 15-20, 2026, Orlando, FL

Last Page

S3848

DOI

10.1093/ajrccm/aamag162.5135

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