Abstract Number: PB0850
Meeting: ISTH 2021 Congress
Background: Congenital Thrombotic Trombocytopenic Purpura (cTTP) Is a Rare Disorder Caused by ADAMTS13 Deficiency and Constitutes a Rare Cause of Strokes
Aims: To recognize cTTP in the differential diagnosis of cryptogenic stroke.
|2001||2002||2006||April 2020||August 2020||February 2021|
|Hemoglobin 11.7-16 mg/dL||12.5||12.8||12.8||11.5||12.7|
|Platelet count (150-450 x103 cells/µL)||142
|Protein C activity (70-130%)||58%||89%|
|Protein S activity (62-163%)||60%||55%|
|Protein S Ag free (70-160%)||60%|
|ADAMTS13 activity||< 5%; 9% after 4 plasma exchanges||5|
|Imaging studies||MRI: Subacute left basal ganglia infarct and acute left parietal lobe infarct
Normal trans-esophageal echocardiogram
|MRI: old left parietal, left caudate, and right frontal (subcortical/parasagittal) infarcts||MRI: acute infarction in the right superior frontal gyrus and subacute infarct at the right inferior frontal gyrus with hemorrhagic conversion||CT: Acute right middle
|Antithrombotic agent||Aspirin low-dose||Warfarin INR target 2-3||Enoxaparin to allow for testing protein C and S||Warfarin INR 1.8 on admission||Apixaban 5 mg twice daily||Apixaban 5 mg twice daily|
|Other||Plasma exchange||Plasma infusions bi-monthly|
A 58-year-old woman was referred to Hematology in August 2020 after developing lingual bleeding and thrombocytopenia (38,000 cells/mm3). She had suffered a stroke at age 39, a transient ischemic attack at age 40 and another stroke at age 57. She was diagnosed with mild protein S deficiency and managed with warfarin. Her second stroke occurred after she had viral symptoms, but SARS-CoV-2 RT-PCR was negative. On admission her INR was subtherapeutic (1.8) and she was switched from warfarin to apixaban. Admission complete blood count (CBC) was normal. However, 4 days later, her platelet count was 131,000 cells/mm3. (Table 1).
Physical exam revealed an ecchymosis on the right arm and a lingual lesion (Figure 1 A-B). Hemoglobin was 11.4 g/dl, platelets 55,000 cells/mm3, reticulocyte 2.37%, LDH 624 mg/dl, and haptoglobin 92 mg/dl. Five schistocytes per high-power field were evident on peripheral blood smear (Figure 1C). She was hospitalized with presumptive diagnosis of thrombotic thrombocytopenic purpura (TTP). Forty eight hours later, she developed new left sided weakness and dysarthria. Magnetic resonance imaging revealed a right medial cerebral artery ischemic stroke. ADAMTS13 was <5% with negative inhibitor. Plasma exchange therapy was performed with normalization in platelet count. ADAMTS13 gene sequencing revealed homozygous mutation 3070 T>G (exon 24). On follow-up, the patient has minimal neurological sequelae. CBC remains normal, and she receives bimonthly plasma infusions as source of ADAMTS-13.
Conclusions: This patient’s subtle hematologic findings underscore the high degree of suspicion required to recognize cTTP as a cause of cryptogenic strokes. ADAMTS13 replacement may prevent recurrences. Peripheral blood smear led to the accurate diagnosis of this unrecognized cause of cryptogenic strokes.
To cite this abstract in AMA style:Desancho M, Beltrami Moreira M. Delayed Diagnosis of Congenital Thrombotic Thrombocytopenic Purpura Presenting as Recurrent Cryptogenic Strokes [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 1). https://abstracts.isth.org/abstract/delayed-diagnosis-of-congenital-thrombotic-thrombocytopenic-purpura-presenting-as-recurrent-cryptogenic-strokes/. Accessed September 24, 2021.
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