Delayed Onset of CD8+ T cell Leukoencephalitis After Bone Marrow Transplantation (P5.355)

Objective: NA Background: Neurologic complications of bone marrow transplantation (BMT) include neurological infections, acute and chronic rejection evident as encephalopathy and idiopathic encephalitis. As the applications for BMT expand and its use becomes more widespread, it is imperative to recognize and understand the complications of this life-saving procedure. Herein, we present a case of delayed-onset progressive encephalopathy following BMT for treatment of T-cell lymphoma. A 50-year-old Caucasian woman with no history of travel outside of Alberta, Canada presented with progressive visual loss following the diagnosis of Grave’s Disease 15 years after an allogeneic BMT. Cranial MRI showed increased T2 signal in the optic nerves and cerebral white matter, extending to the pyramids with minimal enhancement that was accompanied by progressive neurocognitive and motor decline over one year that was refractory to treatment with high dose corticosteroids, intravenous immunoglobulin, and cyclophosphamide. CBC was unremarkable and the patient was afebrile during the entire disease course. Repeated cerebrospinal fluid analyses showed a persistent lymphocytosis and elevated protein without detection of infectious agents based on PCR and serology for herpes viruses (HSV-1/2, VZV, CMV, EBV, HHV6), enteroviruses, retroviruses (HIV-1/2, HTLV-1/2), measles virus, flaviviruses (HCV, WNV) and adenoviruses. All autoimmune markers as well as cerebral angiography were unremarkable, and a recurrent lymphoma was excluded. Both brain biopsy and autopsy performed 6 months and 1 year, respectively, after disease onset showed diffuse CD8+ lymphocytic infiltration with white matter gliosis, blood vessel wall thickening, and occasional focal ischemic lesions. Molecular analyses of white matter and neocortex showed a marked increase in expression of inflammatory gene transcripts including CD3e, IFNG, CD68, IL1B, IL18, and TNFA. Design/Methods: NA Results: NA Conclusions: The present case of treatment-resistant T cell leukoencephalitis broadens the spectrum of BMT-associated neurological complications and highlights the importance of considering idiopathic leukoencephalitis in the differential diagnosis of BMT-associated encephalopathy. Study Supported by: NA Disclosure: Dr. Balcom has nothing to disclose. Dr. Branton has nothing to disclose. Dr. Edguer has nothing to disclose. Dr. Blevins has nothing to disclose. Dr. Yacyshyn has nothing to disclose. Dr. Emery has nothing to disclose. Dr. van Landeghem has nothing to disclose. Dr. Power has nothing to disclose.