Detection of donor-derived CMV-specific T cells in cerebrospinal fluid in a case of CMV meningoencephalitis after cord blood stem cell transplantation.

Cytomegalovirus (CMV) meningoencephalitis is a rather rare complication after allogeneic stem cell transplantation. We describe here the case of a 59-year-old man with acute myeloid leukemia who developed CMV meningoencephalitis after cord blood transplantation. The patient presented with a sudden onset of neurological symptoms, such as convulsion, on day 37. The analysis of cerebrospinal fluid (CSF) sample revealed an increase in the number of cells, which were of donor (cord blood) origin, consisting mainly of T cells. No bacteria were detected in the CSF sample. Real-time PCR analysis revealed that the CSF sample was positive for CMV, but was negative for HHV-6, adenovirus, or BK virus. The patient was diagnosed with CMV meningoencephalitis and received cidofovir. His neurological symptoms were gradually improved and completely disappeared by day 60. CMV-specific dextramer-positive CD8(+) T cells were detected in the peripheral blood and CSF samples, with the frequency being much higher in the CSF. To our knowledge, this is the first report on the appearance of CMV-specific T cells in CSF samples from a patient with CMV meningoencephalitis. Cord blood-derived CMV-specific T cells may develop early after transplantation, enter the intrathecal compartment, and likely contribute to the regulation of CMV-meningoencephalitis.