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 2-year-old boy with a history of severe aplastic anemia (SAA) is undergoing pre-transplant infectious surveillance in anticipation of a myeloablative BMT. He initially presented with autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP) following a viral illness and was treated for AIHA and ITP with intravenous IVIG, rituximab, and steroids. Due to the presence of autoimmune hepatitis, he was also being treated with azathioprine. His cytopenias progressed despite therapy over the next several months. He eventually developed pancytopenia leading to his diagnosis of SAA after BM biopsy showed cellularity of <5% (normal for age 90–95%). Pre-transplant infectious disease surveillance was unremarkable except for an abnormal chest CT. A 2.1 × 1.5 cm round subpleural mass was noted in the left lower lobe with ground-glass attenuation in the left perihilar region. On physical examination, the patient was afebrile, breathing comfortably in room air with a normal respiratory rate and oxygen saturation. Question: How should this patient be managed? Answer: HCT should be delayed while diagnostic procedures can be performed (bronchoscopy with bronchoalveolar lavage) and the patient receives applicable treatment for possible fungal pneumonia.