Human herpesvirus 6 (HHV-6)

Human herpesvirus 6 (HHV-6) refers to two distinct species of double-stranded DNA viruses, HHV-6A and HHV-6B, within the Betaherpesvirinae subfamily (NIH, 2022). These viruses primarily infect T-lymphocytes and are nearly ubiquitous in the human population, with HHV-6B being the leading cause of roseola infantum in early childhood (StatPearls, 2023). A defining biological characteristic of HHV-6 is its ability to establish lifelong latency and, in approximately 1% of humans, integrate its entire genome into host telomeres, a condition known as chromosomally integrated HHV-6 (ciHHV-6) (Journal of Clinical Virology, 2021). While often asymptomatic in healthy individuals, reactivation in immunocompromised patients, such as those undergoing hematopoietic stem cell or solid organ transplantation, can lead to life-threatening encephalitis, pneumonitis, and bone marrow suppression (Frontiers in Microbiology, 2021). Pharmacological intervention focuses on inhibiting the viral DNA polymerase (U38) using nucleoside or nucleotide analogs like ganciclovir and cidofovir, or pyrophosphate analogs like foscarnet (Journal of Clinical Microbiology, 2019). However, these treatments are frequently limited by significant systemic toxicities, including renal failure and neutropenia, necessitating careful monitoring of viral loads and organ function.

Other names

Human B-lymphotropic virusHBLVRoseolovirusHHV-6AHHV-6B

Inhibition of viral DNA polymerase (U38 gene product)