A large prospective study in Africa adds weight to argument that HHV-6B infection is an important cause of febrile status epilepticus.
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.
Inherited ciHHV-6 has been shown to activate under conditions of immunosuppression and and the pan-HDAC inhibitor TSA activates integrated ciHHV-6 in vitro. This is the first case report of HHV-6 activation in a ciHHV-6 patient who received a pan-HDAC inhibitor drug.
Investigators at the National Cancer Institute found that HHV-6+ lymph nodes can be identified in biopsies from both lymphadenopathy and malignancies. They warn that failing to identify HHV-6 in these biopsies can lead to misdiagnosis in lymphoma cases.
A Japanese study found that unexplained fever and biliary atresia are associated with HHV-6B infection in pediatric transplant patients. 100% of seronegative infants developed a primary infection.
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.
A new meta-analysis published in Biology of Blood and Marrow Transplantation shows that transplant patients who reactivate with HHV-6 are 2-3 times more likely to develop acute GVHD.
Using a novel serological assay that can differentiate HHV-6A from HHV-6B, investigators found HHV-6A immediate early antibodies to be associated with an increased risk of non-Hodgkin lymphoma.
In 2016, Italian investigators found HHV-6A in the uterus of 43% of women with unexplained infertility but 0% on controls. Now, a second study found localized HHV-6 infection in women with recurrent implantation failure, but not in controls.
German investigators conducted a broad scale analysis of CD8 T cell responses to HHV-6B, identifying novel epitopes with potential for immunotherapy or vaccines. The strongest responses were directed against an epitope from IE-2.
Investigators at the University of Minnesota found that cord blood transplant cancer patients with HHV-6B reactivation in the first 28 days are almost 4x more likely to relapse in the first two years compared to those with no early reactivation.
Late HHV-6B reactivation after 60 days was an independent risk factor for mortality in Japanese pediatric hematopoietic cell transplant recipients. Older children and those with hematologic malignancy were 10x more likely to develop late reactivation.
HHV-6B directly infects thymocytes, presumably affecting thymopoeisis. A review in Bone Marrow Transplantation explores the intriguing relationship between HHV-6B, T-cell reconstitution and aGVHD after allogenic hematopoietic cell transplantation.
The authors discuss how HHV-6 may contribute to the progression of reactive lymphoproliferative disorders by spurring a dysfunctional immune response.
Dutch investigators found that hematopoietic cell transplant patients with high levels of HHV-6 viremia have reduced late immune reconstitution while early reconstitution was not affected.