[Cerebrospinal fluid findings in chronic active Epstein-Barr virus infection with central nervous system involvement]

As chronic active Epstein-Barr virus (EBV) infection (CAEBV) progresses, EBV-infected tumor cells invade the central nervous system (CNS). To establish a diagnostic procedure for CNS invasion, we retrospectively analyzed cerebrospinal fluid (CSF) obtained from eight patients. Two patients presented with consciousness disturbance and were diagnosed with CNS invasion based on scan and autopsy results, respectively. The remaining six patients were diagnosed without CNS invasion by clinical findings and scans. In the two patients with CNS invasion, the number of mononuclear cells and the protein concentration were increased, whereas the CSF to serum glucose ratio and the adenosine deaminase concentration were raised. In one of the two patients, however, bacterial meningitis could not be excluded. Cytological examination of CSF demonstrated class 1-3. Notably, the CSF EBV-DNA load was positive in all patients, independent of CNS invasion diagnosis, and the CSF load correlated with that of the peripheral blood. Taken together, this indicates that CSF may lack the specific markers of CNS invasion in CAEBV patients. The CSF EBV-DNA load and the cytological analysis did not reflect CNS invasion; therefore, new biomarkers need to be established.