A collaborative team comprised of researchers from Italy and the USA have set out to study the proposed relationship between urticaria and viral infection.  High level HHV-6 reactivation is often seen in individuals that suffer from severe hypsersensitivity conditions such as DIHS and DRESS. In an age matched case-control study published earlier this month in PLoS ONE, the group identified a highly significant correlation between specific herpesvirus infections and acute or recurrent acute urticaria.  Specific herpesvirus infections were diagnosed in 26 of 37 cases compared to only 9 of 37 control children (P=0.0002).  When separated by specific viruses, the authors identified 10 cases of HHV-6 infection, 8 CMV infections, 5 EBV infections, and 4 HSV-1 infections.  READ MORE

Dr. Bhupesh Prusty and his associates in Professor Thomas Rudel's laboratory at Biozentrum University have presented additional evidence that shortened telomeres can cause the release and possible activation of integrated HHV-6. Their work has previously shown that Chlamydia trachomatis infection activates ciHHV-6 and induces the formation of extra-chromosomal viral DNA in ciHHV-6 cells. In an article published by PLoS Genetics this month, Dr. Prusty expands on the theory that a transient shortening of telomeric ends (whether induced via Chlamydia infection or otherwise) may subsequently lead to increased telomeric circle formation and incomplete reconstitution of circular viral genomes containing single viral direct repeats, supporting a t-circle based mechanism for ciHHV-6 activation. READ MORE

Dr. Yoshizo Asano and colleagues in Japan report that in measles immunosuppression, cells sensitized to HHV-6B immediate early and early antigen proteins may suppress replication cycles and virus formation, resulting in an “incomplete” subclinical state of reactivation.  In a new study, the group found that the HHV-6B lymphoproliferative response differed greatly among children suffering from acute measles compared to those with influenza patients and healthy controls, resulting in detectable HHV 6B DNA 18 of 22 subjects with measles, but not in the influenza patients or the healthy population. The authors suggest that the hypercytokinemia produced by measles infection may be the explanation.   READ MORE

Researchers from Quebec have investigated the incidence of ciHHV-6 among children with acute lymphoblastic leukemia (ALL).  Of all patients analyzed (287), only one (0.35%) was determined to be ciHHV-6 positive, ruling out a possible involvement of ciHHV-6 as causative agent for ALL. Interestingly, none of the 288 controls had evidence of ciHHV6. The lowest ciHHV-6 prevalence previously reported was in Japan, at 0.2%, and in studies with larger samples sizes (>500 subjects) in the UK and UK, the prevalence varies between 0.8 -0.85%. The frequency of ciHHV-6 in the Province of Quebec (Canada) therefore appears to be lower than that observed in US and UK..  The authors note that the French-Canadian population is genetically more homogenous than other populations of European descent. A large-scale study involving 20,000 subjects is currently underway to assess whether the incidence of ciHHV-6 in Quebec differs significantly from other regions of the world.  READ MORE