A 13-year-old boy with a history of SAA underwent a matched unrelated BMT 10 months ago. He is engrafted and has no history of GVHD. He is not receiving immunosuppressive therapy and remains on PJP prophylaxis per routine supportive care guidelines. He presents to his hematologist with a recent history of thrombocytopenia and a new-onset excruciating headache refractory to over the counter analgesia. He is admitted to the hospital for platelet transfusion and further imaging. Unfortunately, he experiences a sudden neurologic decline necessitating intubation. A brain MRI reveals numerous enhancing lesions throughout both cerebral and cerebellar hemispheres with punctate microhemorrhages and surrounding vasogenic edema. He undergoes extensive infectious disease testing of blood and cerebral spinal fluid. On lumbar puncture, he is noted to have elevated intracranial pressure (ICP) with a normal ophthalmologic exam. On expanded travel history, he is identified to have lived in China for multiple brief periods during his childhood, which assists in identifying his diagnosis. Question: What is the likely underlying infectious etiology of his MRI findings and neurologic decline? Answer: CNS Toxoplasmosis.
A 6-year-old girl with a history of relapsed AML underwent a myeloablative matched sibling BMT 14 days ago. She is an inpatient in the hospital awaiting engraftment, receiving supportive care with a prophylactic fluoroquinolone antibiotic and transfusions until count recovery, when she suddenly develops fluid-refractory hypotension (blood pressure 70/30 mm Hg). On examination, she is noted to be febrile to 39.6°C and tachycardic at 145 beats/min. She is noted to have crackles on lung auscultation and has a distended but soft abdomen. She is urgently transferred to the PICU where she eventually requires support with multiple vasopressor agents and mechanical ventilation. She is started on broad-spectrum intravenous antibacterial antibiotics and undergoes CT imaging of her abdomen, which identifies colitis. Question: What is the likely underlying etiology of her sudden hemodynamic collapse? Answer: Gram-negative sepsis secondary to translocation of gut bacterial flora.