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 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.
HHV-6 reactivation following haploidentical hematopoietic stem-cell transplant found to predict acute graft versus host disease in China
25% of the patients with HHV-6 reactivation developed aGVHD compared to 18% in those without reactivation.
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.
HHV-6 found in spinal fluid of an immunocompetent patient with possible temporal lobe epilepsy and post-ictal psychosis
A case report suggests possibility that HHV-6 encephalitis may be cause a temporal lobe epilepsy-like episode with associated psychosis
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.
New recommendations for HHV-6 encephalitis from Japan
New guidelines from Japan recommend foscarnet as the first-line treatment for HHV-6 encephalitis, with ganciclovir as second choice. They also recommend a combination therapy in severe cases.
Pruritis, pain and numbness are signs of HHV-6 myelitis: a review of 19 cases
A review of post-transplant cases found that the incidence of HHV-6 myelitis was 4.1%; symptoms of pruritus without rash, pain, numbness, dysuria and constipation are potential signs.
Could anti-cytokine therapy be the key to reducing CNS damage in HHV-6 encephalitis?
Japanese investigators evaluated cytokines and chemokines in the CSF and plasma in HHV-6 encephalitis patients with good and poor prognoses. They found IL-6, IL-7, MCP-1 to be elevated one week before onset, suggesting that these cytokines may be effective targets for intervention.
Differential gene expression pattern shared in herpesviruses, Alzheimer’s & Parkinson’s patients
Researchers from GlaxoSmithKline found a significant overlap in differentially expressed genes shared by those with herpesvirus infections, Alzheimer’s and Parkinson’s. On the other hand, there was no significant overlap between herpesviruses and Type 2 diabetes or Huntington’s disease.
HHV-6 encephalitis: Mayo clinic finds a high rate of severe hippocampal atrophy and neurological deficits
A Mayo clinic review of long-term outcome of patients with HHV-6 encephalitis showed that over 60% showed persistent sequelae associated with severe bilateral hippocampal atrophy. Symptoms included anterograde amnesia, aphasia, headaches, confusion and persistent memory deficits.
BioFire’s FilmArray multiplex encephalitis panel is causing headaches due to confusion over ciHHV-6 status and the meaning of a qualitative positive result
A rapid point-of-care test for patients with encephalitis and meningitis was heralded as a breakthrough, but because the test is not able to determine ciHHV-6 status or viral load, it now has physicians frustrated over how to interpret a positive result.
Oral brincidofovir cut the rate of high level HHV-6 viremia by 80%, suggesting that IV brincidofovir may have potential to prevent HHV-6 encephalitis.
An abstract at the Transplantation & Cellular Therapy Meeting in Houston showed that only 2% of 92 patients treated with oral brincidofovir developed high level reactivation compared to 11% of 61 patients taking the placebo. The results came from an analysis of stored samples from their previous Phase III SUPPRESS trial for CMV prophylaxis. Chimerix’s Phase III trial for cytomegalovirus failed. Although oral brincidofovir reduced CMV viremia during the first 14 weeks, CMV infections bounced back during the 10-week observation period that followed, and there was a higher mortality rate in the drug group. Analysts blamed the higher death rate on the inability of participating physicians to differentiate between bleeding (a side effect of the drug) and acute GVHD. Instead …
89% of the virus found in the spinal fluid of HCT patients in the first 60 days is HHV-6
An analysis of 165 central nervous system viral infections by the Center for International Blood and Bone Marrow Transplant Research found that most were positive for HHV-6. The outcome for patients with viral infection was poor with 50% mortality within 6 months and only 30% survival at 5 years.