Other studies have suggested that reactivation of these viruses could theoretically contribute to a hyperinflammatory state or autoimmune disorders in acute COVID-19, but this study does not provide evidence of that.
Serologic studies of several herpesviruses find that only HHV-6 may be linked to depression.
Longitudinal study of people with a single initial episode of demyelination provides stronger evidence for HHV-6 than EBV in the pathogenesis of MS, but the evidence is not robust.
40% of the patients with HHV-6 DNA had CNS symptoms, compared to 14.3% of the HHV-6 negative patients.
Significant positive correlations were found between HERV family proteins and antibodies to HHV-6A/B but not antibodies to EBV
Studies conducted on serum obtained before development of MS indicate possible protective role
HHV-6 miRNAs and antibodies were identified and significantly correlated with each other in serum and CSF of MS patients
Unique pathways and significantly elevated cytokines were associated with a small cohort of pediatric seizure patients.
Immunocompetent cases are typically children experiencing primary infection with high viral loads in the blood; cases in the immunocompromised typically involve reactivation in the brain tissue, with lower viral loads in the periphery
As with chemotherapy, immunotherapies for cancer can lead to HHV-6 encephalitis
HHV-6A infection at any age, and EBV infection after age 20, were found to be significant risk factors
Psychiatric disorders were the most common prodomal symptom (58%) and this was significantly different from patients with non-herpesvirus encephalitis.
Neuroscientists at Karolinska Institute in Sweden summarized the growing literature linking HHV-6A/B to both illnesses.
Multiplex testing for the causative agents of aseptic meningitis in Saudi Arabia identifies possible etiologic role for HHV-6
While HHV-6B is well known to cause limbic encephalitis in transplant patients, it does not appear to play a role in other forms of limbic encephalitis.