Unique pathways and significantly elevated cytokines were associated with a small cohort of pediatric seizure patients.
Imunocompromised patients with HHV-6 encephalitis have a ratio of CSF/blood viral load >1, whereas children with encephalitis due to primary infection have ratios of <1
Immunocompetent cases are typically children experiencing primary infection with high viral loads in the blood; cases in the immunocompromised typically involve reactivation in the brain tissue, with lower viral loads in the periphery
HHV-6 encephalitis can occur in CAR T-cell therapy and biologic immunotherapy
As with chemotherapy, immunotherapies for cancer can lead to HHV-6 encephalitis
Large serologic study incriminates both EBV and HHV-6A as triggers of multiple sclerosis
HHV-6A infection at any age, and EBV infection after age 20, were found to be significant risk factors
HHV-6 accounted for 5% of all herpetic viral encephalitis in immunocompetent Mexican patients
Psychiatric disorders were the most common prodomal symptom (58%) and this was significantly different from patients with non-herpesvirus encephalitis.
A review of the role of HHV-6A in multiple sclerosis and HHV-6B in epilepsy
Neuroscientists at Karolinska Institute in Sweden summarized the growing literature linking HHV-6A/B to both illnesses.
HHV-6 DNA found in spinal fluid of 8% of patients with aseptic meningitis
Multiplex testing for the causative agents of aseptic meningitis in Saudi Arabia identifies possible etiologic role for HHV-6
No HHV-6 DNA found in the spinal fluid of immunocompetent adults evaluated for limbic encephalitis
While HHV-6B is well known to cause limbic encephalitis in transplant patients, it does not appear to play a role in other forms of limbic encephalitis.
Study of fresh brain tissue confirms a role for HHV-6 in mesial temporal sclerosis
NINDS investigators studied fresh resected brain tissue and found 29 of 54 positive for HHV-6 DNA. Previous studies using formalin fixed and paraffin embedded samples have yielded much lower rates of positivity.
Alcoholism and HHV-6B infection may interact to produce microglial activation, migration in the substantia nigra
Possible synergy between chronic alcohol use and HHV-6B infection of substantia nigra in producing microglial activation
HHV-6A and the suppression of miR155 in Alzheimer’s pathology
Dysregulation of the microRNA miR155 is associated with pathophysiological progression of Alzheimer’s disease. HHV-6A has been shown to suppress miR155.
Latent HHV-6B infection of astrocytes may increase the risk of depression by activating the HPA axis
Japanese investigators show that a protein expressed by latent HHV-6B in astrocytes, results in an influx of extra-cellular calcium, triggering the onset of depression.
Active HHV-6/7 infection found in subset of adult epilepsy patients
HHV-6/7 DNA was found in the plasma of 19.6% of epilepsy patients compared to none of the controls. Protein expression indicating active infection was found in 53% of the HHV-6/7 positive patients.
Multiplex FilmArray Meningitis/Encephalitis assay is useful for diagnosing HHV-6 encephalitis
This multiplex qualitative test for cerebrospinal fluid helps physicians diagnose HHV-6 encephalitis quickly, but interpretation must take into account imaging, ciHHV-6 status and other markers.
Clonally expanded CD8 T cells in spinal fluid of Alzheimer’s patients suggest an adaptive immune response to pathogens
Researchers at the NIH used RNA-Seq cells from skin and blood to study the underlying mechanisms in DIHS/DRESS and identified both HHV-6 and JAK-STAT pathways as potential targets. Central memory CD4+T cells were enriched with HHV-6B.