Multimodal techniques failed to detect cytomegalovirus in human glioblastoma samples

The role of the human cytomegalovirus (HCMV) in gliomagenesis is largely debated. Contradictory data exist regarding the sensitivity and specificity of HCMV detection techniques, including immunohistochemistry (IHC), in situ hybridization (ISH), and RNA and DNA sequencing. The aim of this study is to detect HCMV in glioblastoma (GBM) tumor samples using IHC, ISH, and real-time PCR (qPCR), as well as to correlate the findings with serological status and HCMV DNA load in blood. Forty-seven patients with histopathological diagnosis of GBM and HCMV serological status were retrospectively reviewed. HCMV DNA quantification in whole blood was performed in 31 patients. The detection of HCMV in tumor samples was performed using IHC in 42 cases, ISH in 10 cases, and qPCR in 29 cases. All but two patients were taking high steroid doses at the time of biological testing. HCMV seroprevalence was 68%. Active infection with HCMV DNA detected in blood was diagnosed in 6 out of 21 (28%) seropositive patients. HCMV was not detected in GBM samples using IHC or ISH, while qPCR was positive in one case (also positive for blood HCMV DNA). These data do not support a crucial role of HCMV in GBM tumorigenesis. HCMV might be reactivated in GBM patients, due to steroid treatment.