P0728 / #2117: IMMUNE ENCEPHALITIS IN TWO PATIENTS AFTER HEMATOPOIETIC CELL TRANSPLANTATION

Abstract

Aims & Objectives: To report two pediatric cases with non-infectious encephalitis after an allogeneic hematopoietic cell transplantation (allo-HSCT). Methods: Case report in a pediatric intensive care unit (PICU) in a tertiary hospital. Results: A 12-year-old boy, with history of acute myeloid leukemia and mild gastrointestinal graft-versus-host disease (GvHD) after an allo-HSCT, was admitted to our PICU with acute neurological symptoms. Initially, an infectious etiology was suspected as he was lymphopenic, but all laboratory tests, microbiological serum and CSF studies were normal except for Coronavirus HKU1 in a nasopharyngeal sample. MRI revealed a rhomboencephalitis with supratentorial involvement, electroencephalogram showed moderate diffuse encephalopathy. Response to cefotaxime, foscarnet, corticoids and immunoglobulins was poor. Five days after donor lymphocytes infusion, clinical and electroencephalographic improvement was noted. A 6-year-old girl with a primary immunodeficiency developed a severe GvHD with multiple organ involvement after an allo-HSCT. She required PICU admission with a refractory convulsive status epilepticus. Electroencephalogram showed epileptiform discharges and unspecific atrophy was described in MRI. All complementary tests were negative except for CSF lymphocytosis and 14-3-3 protein. Empiric treatment with intravenous immunoglobulins, plasmapheresis and corticosteroids was initiated, but failed to improve the patient’s condition. A ventilator-associated pneumonia lead to patient’s death at day 10. On autopsy, CNS findings were consistent with immune encephalitis, CNS GvHD was postulated as a possible diagnosis. No histological findings were suggestive of Creutzfeldt-Jakob disease. Conclusions: Recent research highlights the CNS immunological function. Faced with neurological deterioration in a patient who has received a hematological stem cell transplant, GvHD must be considered as a possible cause.