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.
An 8-year-old boy, with a history of relapsed acute myeloid leukemia (AML) after an UCT, is admitted to the hospital to begin preparation for a second HCT, using a second UCB graft that will be infused in 7 days. On the third day of his myeloablative preparative chemotherapy, 4 days prior to infusion of his second transplant, he develops a temperature of 39.8°C. On examination, he is hypotensive (blood pressure is 64/32 mmHg) and tachycardic at 150 beats/min. His lungs are clear to auscultation. Blood cultures are obtained from his central line, and he is started on broad-spectrum empiric antibacterial antibiotics. He receives multiple fluid boluses and his hemodynamic status improves. Question: What is the likely underlying etiology of his hemodynamic change? Answer: Gram-positive infection of his central venous catheter.