Over a dozen studies have now found HHV-6 to predict aGVHD, but this is the first to correlate viral reactivation with poor CD4+ cell immune reconstitution.
Antibodies to HHV-6 and VZV dUTPases were significantly elevated in Gulf War Illness patients compared to controls, and EBV dUTPase antibodies were elevated in Chronic Fatigue Syndrome patients.
HHV-6B induces unique, region-specific DNA hypomethylation, and findings suggest that the epigenetic modification may facilitate HHV-6B integration.
A new study shows that HHV-6A direct repeats can survive alone in an integrated state without the rest of the viral genome. The study also identified non-telomeric integration of HHV-6A in both in vitro cultured cells as well as one iciHHV-6A patient.
Human papillomavirus 4 is a benign strain not associated with cancer. However, in a woman with inherited chromosomally integrated HHV-6A, a high grade vaginal squamous lesion developed rapidly. The authors warn that there may be a synergistic effect between HPV4 and iciHHV6A.
The group that recently discovered a ligand for U24 has expanded upon their previous experiments to further elucidate the viral protein’s interactions and functions as they pertain to MS.
Investigators at Washington University have sequenced a murine herpesvirus and determined that it is closely related to HHV-6 & 7. Named Murine Rosesolovirus (MRV), the virus causes severe depletion of CD4+ T cells and thymic necrosis in young mice. The authors believe that MRV will be a useful mouse model to study the impact of HHV-6 & 7 in humans.
A retrospective study of allogeneic hematopoietic stem cell transplant patients at University of Washington found that reactivation of several double stranded DNA viruses significantly increased the risk of overall mortality, as did an increased quantitative burden of viral exposure. HHV-6B conferred a significantly increased risk for overall mortality.
A group led by Professor Niza Frenkel of Tel Aviv University in Israel has determined that HHV-6A limits its own replication to avoid detection and destruction, leading to a long life-cycle with limited propagation. This finding may reveal the mechanism behind persistent HHV-6A infections and help explain some disease associations.
Investigators from Uppsala University in Sweden found that HHV-6 IgG reactivity was significantly lower in Alzheimer’s Disease patients compared to controls. The authors suggest reduced immunity may be one reason why past studies have found increased levels of HHV-6 DNA in the brains of Alzheimer’s patients compared to controls.
A young woman on rituximab and two other immunomodulatory agents for the treatment of dermatomyositis developed encephalitis with severe anterograde amnesia. As the use of biologic treatments for refractory autoimmune disease has been increasing, physicians are advised to consider HHV-6 and offer prompt antiviral therapy to limit irreversible morbidity.
Investigators from the University of Ferrara, Italy have found evidence suggesting that high levels of U94 in ciHHV6 may predispose to the formation of marker chromosomes. A patient with diffuse large B-cell lymphoma positive for inherited chromosomally integrated HHV-6A and HHV-6A was also found in a marker chromosome, an abnormal piece of chromosome that is seen in some leukemia and lymphomas.
A group from Japan has found that the deformation of erythroblasts seen in transient erythroblastopenia of childhood, is caused by HHV-6. Erythroblasts are progenitor cells in the bone marrow, necessary for the production of red blood cells.
HHV-6 has been linked in numerous studies to multiple sclerosis. Now, investigators at the University of British Columbia have published new data suggesting that HHV-6A may be a key player in the development of multiple sclerosis. The investigators propose that the viral protein U24 may dysregulate myelination.
A group from Aarhus University propose that differing isoform patterns of CD46 correlate with the ability of some HHV-6B strains to enter T cells.