The predictive value of cerebrospinal fluid Epstein-Barr viral load as a marker of primary central nervous system lymphoma in HIV-infected persons

Abstract Background The presence of Epstein-Barr virus (EBV) DNA in cerebrospinal fluid (CSF) is used as a marker of HIV-associated primary central nervous system lymphoma (PCNSL). In our setting, EBV DNA is frequently detected in the CSF of HIV-infected patients with miscellaneous neurological diseases and thus its presence is a poor predictor of PCNSL. Objectives To determine whether quantification of EBV DNA in CSF improves its diagnostic specificity for PCNSL. Study design EBV viral loads were determined on CSF samples from 55 HIV-infected patients with CNS disease. Results Twenty of the 55 patients had detectable EBV DNA in their CSF (median viral load 6120 copies/ml, range 336–1,034,000 copies/ml). PCNSL was confirmed in 2 patients. Their CSF EBV loads were 1,034,000 and 15,460 copies/ml, respectively. Using a cut-off of 10,000 copies/ml improved the specificity and positive predictive value (PPV) compared to a qualitative result for the diagnosis of PCNSL (96% vs. 66% and 50% vs. 10%, respectively). Conclusion EBV DNA is commonly detected in CSF of HIV-infected patients. Quantitative PCR improves the diagnostic specificity, however, the PPV remains too low for it to be used as an isolated marker for PCNSL.