Case Presentation: A 72 year-old woman with history of thrombotic thrombocytopenic purpura (3 years ago, in remission after rituximab), hypertension, and hyperlipidemia presented as an inpatient transfer to a stroke center after presenting with left facial droop, left-sided weakness, and dysarthria with a right middle cerebral artery occlusion on CT imaging. On clinical exam, the patient was confused and had worsening left hemiparesis. She was afebrile and hypertensive to 150/71. NIH Stroke scale was 9, and a right prefrontal infarct was shown on MRI.Labs were notable for platelets of 29, hemoglobin of 9.7, and creatinine of 1.2. Further hemolysis workup showed a haptoglobin level of < 20, normal INR, Coombs negative, and unconjugated bilirubin 2.2 (total bilirubin of 2.7). Multiple schistocytes were present on blood smear. A PLASMIC risk score for TTP was calculated at 7 out of 7, indicating high risk of TTP. She was promptly treated for suspected TTP with plasma exchange and methylprednisolone. Her neurologic status improved within hours following plasma exchange, with increasing left-sided grip strength, fluent speech, and decreased confusion. Two days after admission, ADAMTS13 activity came back as undetectable, confirming TTP diagnosis.
Discussion: TTP typically presents as microthrombi in small vessels, and this case highlights a rare manifestation of TTP as a large vessel occlusion leading to a stroke in the middle cerebral artery. There are limited documented cases of TTP presenting as large vessel occlusions [1]. Despite this patient’s history of TTP, the initial presentation of her stroke masked recognition of relapsed TTP. TTP is typically taught to present as a pentad of fever, anemia, thrombocytopenia, renal dysfunction, and neurologic impairment; however, this pentad is specific but not sensitive. This patient presented with just 3 of these features (anemia, thrombocytopenia, and neurological deficits). Not recognizing clinical presentation without all of these features can delay treatment, especially when presenting with embolic etiologies, such as stroke or myocardial infarctions, where alternative vascular causes are primarily considered. This case demonstrates that admitted patients with new anemia and significant thrombocytopenia, should have further evaluation for etiologies to catch rare but emergent conditions. This also indicates a potential future need for stroke prevention guidelines that are specific for patients with confirmed TTP diagnoses [2]. It is also important to highlight that this patient was considered to be in TTP remission following treatment with rituximab; however, she relapsed with an uncommon manifestation of TTP in a middle cerebral artery stroke. Rituximab has been shown to produce shorter relapse free survival among Black patients compared to White patients with immune-mediated TTP [3]. While TTP is a rare diagnosis, limited diversity and access to trial participation may lead to racial disparities in treatment and monitoring of TTP, and it warrants the necessity for hospitalists to identify and manage patients with signs of TTP independent of remission status.
Conclusions: While TTP is taught to present as a pentad which manifests with microvascular thrombi, this case, alongside recent literature, demonstrates the increasing incidence of macrovascular occlusions secondary to TTP and highlights the importance of hospitalists to consider prompt evaluation for TTP in patients with new onset anemia and thrombocytopenia.