High dose steroids given in the first week appears to prevent HHV-6 reactivation in DRESS/DIHS patients by suppressing T-cell activation and serum interleukin-2 receptor (sIL-2R) levels. In contrast, a late start of steroid therapy resulted in a persistently high viral load for at least three weeks.
Herpesvirus co-infections, particularly HHV-6 and CMV, cause severe lymphopenia, pneumonia, and an increased risk of acquiring bacterial and fungal infections in non-transplant acute leukemia patients undergoing chemotherapy.
Allogenic transplant patients who received prophylactic oral brincidofovir as part of a CMV trial had a reduced HHV-6B reactivation and lower viral loads.
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.
Researchers led by Yasuko Mori of Kobe University in Japan have developed an animal model will be useful for studying the pathogenicity of HHV-6B in conditions such as acute GVHD and idiopathic pneumonia
A systematic review suggests that sodium imbalance is associated with HHV-6 encephalitis and syndrome of inappropriate diuretic hormone (SIADH) could serve as an early warning
Transplant patients born with chromosomally integrated HHV-6 have elevated levels of C-reactive protein and tumor necrosis factor receptor 1, both markers associated with increased risk of acute graft-versus-host disease.
European guidelines recommend treating HHV-6 disease with either foscarnet or ganciclovir, in contrast to the Japanese guidelines that recommend foscarnet as first line treatment due to a lower mortality rate.
Investigators at the Fred Hutchinson Cancer Research Center and University of Washington in Seattle found that HHV-6B in lung fluid of bone marrow transplant recipients with pneumonia is associated with a 2-fold increased risk of death. Importantly, HHV-6B positive patients who were treated with an antiviral had a 60% lower risk of death.
A third of patients with acute liver failure were found to have a betaherpesvirus infection when tested for all herpesviruses. HHV-6 was the most common infection, followed by CMV and HHV-7. No other herpesviruses were found.
Persistent HHV-6 infection in the liver is hard to detect from plasma samples and liver biopsies may miss spotty infections. Bile fluid may be the best method for detecting herpesviruses that impact the liver.
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.
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.
In a prospective study, patients with HHV-6 infection took longer to recover neutrophils and platelets. They also spent significantly more time in the hospital with complications.
A new study reports a surprisingly low rate of HHV-6 reactivation in recipients of half-matched bone marrow grafts using a reduced-intensity conditioning regimen. The authors speculate that the corticosteroid used for prophylaxis may have suppressed cytokine production which in turn limited reactivation of HHV-6.