Italian investigators showed that HHV-6A and -6B infection of natural killer cells have a remarkable effect on the expression of miRNAs and transcription factors, which in turn control natural killer cell development, maturation and function.
A team at University of Pittsburgh analyzed a large database of deep sequencing data from tumor and control tissues to look for viral sequences in 22 different cancers. They were surprised to find several herpesviruses in gastrointestinal cancers but not in control tissues.
The 11th International Conference on HHV-6 & 7 will be held in beautiful Quebec City, Canada June 23–26, 2019.
HHV-6 is rarely identified as the cause of liver dysfunction in immunocompetent children, in part because HHV-6 is not included in routine testing, and HHV-6 infections can be highly localized to the liver. In this case, an alert team in Arizona identified HHV-6 by needle biopsy.
Japanese investigators described HHV-6 myelitis in patients who had received cord blood transplantations and report that where HHV-6 reactivation is suspected, early antiviral intervention can dramatically improve patient outcomes.
Investigators at Fred Hutch Cancer Research Center found that HHV-6B is the first DNA virus to reactivate at a median of 3 weeks, compared to CMV, EBV and Adenovirus at 5-6 weeks. HHV-6B also peaked rapidly, unlike other DNA viruses that took 3-6 weeks to reach peak viral load. HHV-6B reactivation resulted in increased mortality after 100 days.
British researchers used molecular dating methods to determine that most strains of iciHHV-6 come from a small number of ancient human ancestors; the youngest found lived over 24,000 years ago. These ancient strains vary considerably from modern non-inherited strains of HHV-6A and appear just as likely to activate as their more modern cousins.
HIV+ patients on antiretrovrial therapy with high levels of HHV-6 shedding had lower levels of IL-6 and other inflammatory markers. While HIV+ patients had increased shedding of EBV and CMV, there was no difference in shedding between patients and controls for HHV-6.
Two new NIH grants awarded for studies related to HHV-6A and CNS disease. A Stanford group was also funded to develop whole genome sequencing platform to study HHV-6 and four other viruses post-transplant.
Half of autologous hematopoietic cell transplant patients with HHV-6 reactivation exhibit fever plus a collection of symptoms that include diarrhea, rash and pneumonia.
Swedish investigators have found HHV-6 protein in the pancreatic islet cells of both type 1 diabetes patients and controls. The viral load was higher in the islet cells than in surrounding tissues. Unfortunately, they did not provide data on the difference between patients and controls in the viral load.
HHV-6 infections in the liver transplant patients can’t be diagnosed in the blood. Ganciclovir prophylaxis for CMV cuts the rate of HHV-6 reactivation from 39% to 11%.
Prevalence of HHV-6A and HHV-6B was evenly divided in HIV+ patients in Western Africa, with over 6.3% positive for HHV-6 A and 5.0% for HHV-6B. HHV-6A was more common among those with a low viral HIV viral load.
Although only a small number of pediatric cases have been reported in literature, the authors conclude that evidence suggests HHV-6 should be considered as a causative agent of inflammatory cardiomyopathy, particularly in young children (under 3 years of age) who might be experiencing a primary infection.
Investigators in Japan studied 145 patients who developed HHV-6 encephalitis. At 100 days after transplantation, the overall survival rate was just 58.3%, compared with 80.5% for patients who did not develop encephalitis. High-dose antiviral therapy was shown to mitigate high mortality rates in these patients.