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.
Mycophenolate mofetil tied to increased risk of HHV-6 encephalitis after allogenic transplantation
Japanese investigators found that those who were administered mycophenolate mofetil along with a calcineurin inhibitor developed a much higher rate of infection: 12% in cord blood and 6% in other transplants.
HHV-6 and EBV found in the brain tissue of Rasmussen’s Encephalitis patients
Chinese investigators found a high prevalence of HHV-6 and Epstein Barr virus in the brain tissues of children with Rasmussen’s encephalitis but in none of the controls. There was a significant association between viral presence and brain atrophy, raising a strong suspicion for the involvement of both viruses.
Acute seizures in children: a new study highlights the role of infections and inflammation
NINDS investigators found that children with febrile seizures have elevated inflammatory cytokines compared to healthy controls and children with fever. One of those cytokines, Il-1β, correlated with HHV-6 saliva viral load.
Why did these transplant protocols result in such a high rate of HHV-6 encephalitis (32%) and organ disease (46%)?
Investigators in Spain and Italy attempted to reduce the rate of acute GVHD in pediatric transplant patients by infusing manipulated stem cells. Not only was there no reduction in expected acute GVHD, the patients experienced an unusually high rate of HHV-6 disease.
HHV-6 encephalitis in 32% of pediatric leukemia patients depleted of naïve T cells
Although depleting naïve T cells has been successful in preventing acute graft vs host disease in several studies, investigators from Spain reported an unexpectedly high incidence of HHV-6 encephalitis in a cohort of haploidentical transplant patients.
FilmArray encephalitis/meningitis panel causing confusion due to undiagnosed ciHHV-6
Many institutions are now using a new multiplex qualitative assay to get rapid diagnosis in encephalitis cases in the clinic. Unfortunately, this system cannot identify cases of inherited chromosomal integration, which creates confusion.
Foscarnet prophylaxis reduces severity but does not prevent HHV-6 encephalitis
A Japanese trial of foscarnet prophylaxis in cord blood transplant patients was successful in reducing severity and mortality as well as suppressing high viral loads, but it failed to prevent encephalitis. The authors note that the blood brain barrier must be inflamed to allow effective penetration of the drug into the central nervous system and speculate that the prophylaxis may have protected the meninges.