Renee Morecroft, Jyoti Moorjani, Mohamed Hussam Hallak, Tathana Rivera Hernandez, Isabella Estrada, Hammad Awad, Payam Nabizadeh-Eraghi
An 85-year-old man developed acute neurologic dysfunction, severe thrombocytopenia, microangiopathic hemolytic anemia, and ADAMTS13 activity of 4.6% after TMP-SMX reexposure. Seven plasma-exchange sessions plus corticosteroids produced rapid recovery. This case highlights the diagnostic challenge of possible TMP-SMX-associated iTTP and the importance of prompt treatment.