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.
An 11-year-old boy with an immunodeficiency disorder underwent an HLA matched unrelated BMT. His transplant course was relatively uncomplicated and he had appropriate count recovery. On day 26 after his transplant, he developed high persistent fevers and a gradual change in mental status leading to florid encephalopathy. He was transferred to the PICU after experiencing a short tonic-clonic seizure and inability to maintain his airway. After intubation in the PICU, he underwent a lumbar puncture that revealed CSF findings of 5 WBC, 0 RBC, 96 mg/dl protein, and 47 mg/ml glucose (greater than two-third of the blood sugar level). CSF bacterial aerobic and anaerobic cultures remained negative. He was started on broad-spectrum antimicrobials including empiric antifungal and antiviral agents. Question: What viral infection is an emerging cause of encephalopathy in the HCT population? Answer: HHV6.