Pearls & Oy-sters: Seronegative Eastern Equine Encephalitis in an Immunocompromised Stem-Cell Transplant Recipient

Abstract

Altered mental status in immunosuppressed patients has a wide differential of potential etiologies. In this case, a 27-year-old male presented with encephalopathy, nausea, vomiting, and fevers. His medical history was significant for acute myeloid leukemia in remission after allogenic hematopoietic stem cell transplant 17 months prior complicated by graft versus host disease affecting his skin treated with sirolimus. A lumbar puncture was performed with a lymphocytic pleocytosis, mildly elevated protein, and negative gram stain and bacterial and fungal cultures. His examination deteriorated and he became comatose with loss of pupillary and corneal reflexes. An MRI of his brain demonstrated T2/FLAIR signal abnormality involving the bilateral basal ganglia, mesial temporal lobes, and entire brainstem along with bilateral temporal parenchymal and leptomeningeal enhancement. Ultimately, diagnosis was made via metagenomic polymerase chain reaction sequencing from his cerebrospinal fluid. This case highlights diagnostic challenges in immunosuppressed patients as antibodies against the causative antigen were negative (potentially related to decreased antibody production in the setting of immunosuppression).