A prospective study authored by Joshua Hill and Danielle Zerr determined that higher than average HHV-6B DNA levels increased the odds of developing delirium after cord blood transplantation (CBT) by almost three fold. Patients with DNA loads in the top quartile had a 4.5 fold increase in delirium.  The authors point out that HHV-6B DNA may not always be detectable in liquid compartments such as plasma and cerebrospinal fluid at the time of delirium symptoms.The study also demonstrated that intensified antiviral prophylaxis with ganciclovir and valacyclovir may mitigate HHV-6B reactivation. READ MORE

Researchers at the University of Ferrara, Italy, have published a new article in the Archives of Virology detailing HLA molecule modulation caused by HHV-6A infection of mesothelial cells. Their study demonstrates, for the first time, that human mesothelial cells are susceptible to HHV-6A infection in vitro. They also show that the virus causes modulated HLA expression on the cell surface, inducing the de novo expression of HLA class II and HLA-G. READ MORE

A team from the University of Leiden, Netherlands, report that HHV-6 may be the cause of “fever of unknown origin” in 30% of stem cell transplant (SCT) patients. By the third week after SCT, 70% of HHV-6 positive patients had a skin rash, compared to 39% of HHV-6 negative patients (P=0.01). READ MORE

Investigators in Yokohama, Japan studied 236 patients who underwent allogenic hematoepietic stem cell transplantation (allo-HSCT) and found that the 59% with HHV-6 reactivation had significantly higher non-relapse mortality (28% vs 14%) as well as worse overall survival at three years (42% vs. 59%). Subgroup analysis indicated that HHV-6 reactivation with associated acute GVHD was primarily found in the group with myeloablative conditioning. HHV-6 was also associated with a higher rate of CMV reactivation. READ MORE

A group from Sapporo Medical University studied 105 post HSCT patients and determined that 7 developed CNS dysfunction in the first 42 days after transplant. Six out of the 7 were positive for HHV-6, but none of the other 12 pathogens tested. Four patients (3.8%) were diagnosed with HHV-6 encephalitis. The group used a qualitative multiplex PCR and then used a quantitative PCR to confirm the results. READ MORE