Soru

A $42$-year-old woman is brought to the emergency department by her husband due to a $2$-day history of progressive confusion and generalized weakness. She reports having a mild upper respiratory illness one week ago. Her temperature is $38.2^\circ\text{C}$ ($100.8^\circ\text{F}$), blood pressure is $130/80\text{ mmHg}$, and pulse is $102/\text{min}$. Physical examination reveals scleral icterus and scattered petechiae on her bilateral lower extremities. Neurological examination shows intermittent disorientation to time and place, but no focal motor or sensory deficits. Laboratory studies show:

* Hemoglobin: $7.8\text{ g/dL}$
* Platelets: $18,000/\text{mm}^3$
* Leukocytes: $8,400/\text{mm}^3$
* Creatinine: $1.1\text{ mg/dL}$
* Total bilirubin: $3.8\text{ mg/dL}$ (Indirect: $3.1\text{ mg/dL}$)
* Prothrombin time: $12\text{ seconds}$ (Normal: $11$-$14\text{ seconds}$)
* Partial thromboplastin time: $28\text{ seconds}$ (Normal: $25$-$35\text{ seconds}$)

Peripheral blood smear reveals numerous schistocytes.

Which of the following is the most likely diagnosis?