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.
A 9-year-old boy with a history of cerebral adrenoleukodystrophy (c-ALD) underwent an UCT approximately 18 months ago. His HCT course was complicated by autoimmune cytopenias for which he received multiple therapies over the last year including rituximab, IVIG, mycophenolate mofetil (MMF), daratumumab, and steroids. He presented to the ED with increased work of breathing and oxygen saturation of 86% while breathing room air. On auscultation of his lungs, he had poor aeration bilaterally and copious coarse breath sounds. His Covid-19 testing was negative. He was transferred to the PICU for respiratory support. At the time of admission, he was not on any prophylactic antimicrobial agents. Question: What is the likely underlying etiology of his sudden respiratory distress? Answer:\nPneumocystis pneumonia.