Complications of erythropoietin in navigated brain gene therapy: A case report

Erythropoietin has been used to treat brain injuries and increase preoperative hemoglobin levels. A seven-year-old boy presented with aromatic L-amino acid decarboxylase deficiency, an enzyme responsible for producing dopamine and serotonin. He received gene therapy through an injection of adeno-associated viral vectors to the bilateral putamen, but not to the brain stem where serotoninergic neurons reside. An erythropoiesis-stimulating agent was given before surgery to increase his preoperative hemoglobin level. Unexpectedly, in preoperative planning, prominent cerebral vasculatures were visualized on magnetic resonance imaging. One month later, symptoms of serotonin overproduction, including vomiting, diarrhea, and high fever presented, which lead to dehydration and shock. We speculated that the viral vector spread from the putamen through the proliferating vasculature to the brain stem, causing the complication. ? 2020 The Authors