Interactions between High Seroreactivity to Human Herpes Virus 6A and Epstein-Barr Virus in MS Development: A Presymptomatic Case-Control Study.

Synergistic interactions between human herpesvirus 6A (HHV-6A) and Epstein-Barr virus (EBV) are hypothesized in the etiopathogenesis of multiple sclerosis (MS). This study investigated if HHV-6A and EBV seroreactivities interact regarding the risk of developing MS. Antibodies against viral antigens were analyzed in biobank samples from 670 individuals who later developed MS and matched controls. Additive interactions were analyzed. A significant interaction between HHV-6A and EBNA-1 seroreactivities was observed in study participants above the median age of 24.9 years (attributable proportion due to interaction = 0.45). This finding supports the hypothesis that HHV-6A and EBV infections interact in MS development. ANN NEUROL 2024;96:302-305.

Viral myocarditis in combination with genetic cardiomyopathy as a cause of sudden death. An autopsy series.

Sudden cardiac death (SCD) is a major public health issue worldwide. In the young (< 40 years of age), genetic cardiomyopathies and viral myocarditis, sometimes in combination, are the most frequent, but underestimated, causes of SCD. Molecular autopsy is essential for prevention. Several studies have shown an association between genetic cardiomyopathies and viral myocarditis, which is probably underestimated due to insufficient post-mortem investigations. We report on four autopsy cases illustrating the pathogenesis of these combined pathologies. In two cases, a genetic hypertrophic cardiomyopathy was diagnosed in combination with Herpes Virus Type 6 (HHV6) and/or Parvovirus-B19 (PVB19) in the heart. In the third case, autopsy revealed a dilated cardiomyopathy and virological analyses revealed acute myocarditis caused by three viruses: PVB19, HHV6 and Epstein-Barr virus. Genetic analyses revealed a mutation in the gene coding for desmin. The fourth case illustrated a channelopathy and a PVB19/HHV6 coinfection. Our four cases illustrate the highly probable deleterious role of cardiotropic viruses in the occurrence of SCD in subjects with genetic cardiomyopathies. We discuss the pathogenetic link between viral myocarditis and genetic cardiomyopathy. Molecular autopsy is essential in prevention of these SCD, and a close collaboration between cardiologists, pathologists, microbiologists and geneticians is mandatory.

Metagenomic Next-Generation Sequencing (mNGS) of cerebrospinal fluid for diagnosis of human herpesvirus 6B encephalitis following transplantation for severe aplastic anemia.

INTRODUCTION: Human herpesvirus 6B (HHV-6B) encephalitis is common in immunosuppressed patients and presents a diagnostic challenge for physicians. Metagenomic next-generation sequencing (mNGS) may facilitate early diagnosis of HHV-6B encephalitis. Herein, we described a case of HHV-6B encephalitis following transplantation for severe aplastic anemia (SAA) diagnosed by mNGS. CASE SUMMARY: A 31-year-old male underwent myeloablative haploid hematopoietic stem cell transplantation for the treatment of SAA. On day + 21 after transplantation, the patient developed symptoms such as sudden epilepsy, drowsiness, memory dislocation, and memory loss. HHV-6B encephalitis was confirmed based on cranial MRI and mNGS of cerebrospinal fluid. Following antiviral therapy with sodium foscarnet, the symptoms improved and HHV-6B was negative by mNGS. There were no serious sequelae. Currently, the patient is in good health and is still under follow-up. CONCLUSIONS: A case of HHV-6B encephalitis after SAA transplantation was diagnosed by mNGS of cerebrospinal fluid in time and was effectively treated with sodium foscarnet.

Latent human herpesvirus 6 is reactivated in CAR T cells.

Cell therapies have yielded durable clinical benefits for patients with cancer, but the risks associated with the development of therapies from manipulated human cells are understudied. For example, we lack a comprehensive understanding of the mechanisms of toxicities observed in patients receiving T cell therapies, including recent reports of encephalitis caused by reactivation of human herpesvirus 6 (HHV-6)1. Here, through petabase-scale viral genomics mining, we examine the landscape of human latent viral reactivation and demonstrate that HHV-6B can become reactivated in cultures of human CD4+ T cells. Using single-cell sequencing, we identify a rare population of HHV-6 'super-expressors' (about 1 in 300-10,000 cells) that possess high viral transcriptional activity, among research-grade allogeneic chimeric antigen receptor (CAR) T cells. By analysing single-cell sequencing data from patients receiving cell therapy products that are approved by the US Food and Drug Administration2 or are in clinical studies3-5, we identify the presence of HHV-6-super-expressor CAR T cells in patients in vivo. Together, the findings of our study demonstrate the utility of comprehensive genomics analyses in implicating cell therapy products as a potential source contributing to the lytic HHV-6 infection that has been reported in clinical trials1,6-8 and may influence the design and production of autologous and allogeneic cell therapies.

Detection of human herpesvirus 6 in pediatric CSF samples: causing disease or incidental distraction?

Interpretation of human herpesvirus type 6 (HHV6) detection in the cerebrospinal fluid (CSF) of children can be complex; the virus can cause acute infection, reactivation, or can be inherited chromosomally integrated (iciHHV6). Our objectives were to determine the prevalence of HHV6 including iciHHV6 in CSF and compare the clinical and laboratory characteristics with and without iciHHV6 in our patient population. Overall, the prevalence of HHV6 and iciHHV6 was 2.4% and 0.85%, respectively. Children with iciHHV6 were significantly younger and less likely to present with fever. Septic infants (≤60 days) accounted for 65.2% (15/23) of the iciHHV6 patients. Patients with iciHHV6 had higher viral loads in CSF and whole blood. Twenty-one (91.3%) patients with iciHHV6 and 12 (33.3%) without ici-HHV6 were determined to have an incidental detection of HHV6 not associated with presenting symptoms. Molecular detection of HHV6 in CSF is not always associated with HHV6 infection and may represent iciHHV6 particularly in infants evaluated for sepsis.

Non-A to E hepatitis in children: Detecting a novel viral epidemic during the COVID-19 pandemic.

During the COVID-19 pandemic, two further novel viral epidemics were described in 2022, monkeypox virus infections in men having sex with men and non-A to E hepatitis in children. The latter occurred in the first half of 2022 with about 1000 cases worldwide, necessitating liver transplantation in 5% and causing death in 2% of patients. It took some effort to clarify the cause of the novel hepatitis epidemic. Researchers were confronted with a polymicrobial viral infection consisting of an adenovirus-associated virus type 2 (AAV2) infection, co-occurring with either human adenovirus type 41 (HAdV41) or herpesvirus infections; most prominently human herpesvirus type 6 (HHV-6). AAV-2, a small Dependovirus of the Parvovirus family, needs these helper viruses for its replication. AAV2 is used as a vector for liver-targeting gene therapy but was not previously known to cause acute hepatitis. HAdV41 and HHV-6 are mostly known to cause diarrhoea and febrile illnesses associated with skin rashes in children, respectively. Except for a few case reports of HHV-6 hepatitis, HAdV and HHV-6 are mostly known as major pathogens in immunosuppressed transplantation patients. A potential role of SARS-CoV-2 has also been discussed but the most popular hypothesis involves an indirect role of the COVID-19 pandemic for this novel disease. Exposure to HHV-6 infections occurs nearly quantitatively during the first year of life. Social distancing measures, followed by the lifting of these measures in 2022 might have caused a delayed exposure to multiple, normally benign childhood viral infections eliciting a dysregulated immune response with pathological effects for liver cells. In the fall of 2022, when these conditions were not longer met, case numbers dwindled. The hypothesis of an unequilibrated immune response instead of intrinsic cytopathic activity of the implicated viruses is further supported by the enrichment of a particular HLA allele in cases over controls.

Epstein‒Barr virus and human herpesvirus 6 infection in patients with systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is a complex autoimmune disease, and the etiology is still unclear. Some studies have indicated that viral infection might contribute to the development of SLE. METHODS: A total of 105 individuals with SLE and 110 matched healthy controls were tested for EBV-specific DNA fragments in peripheral blood monocytes by PCR-Southern blotting. The expression of EBV-encoded genes was determined by RT-PCR and Southern blotting in EBV-positive patients. Serum EBV-specific IgM antibody was determined by ELISA. HHV-6 DNA in peripheral blood monocytes of those SLE patients and normal controls was tested by nested PCR. RESULTS: Statistical analysis showed that the EBV-positive rate of SLE patients was significantly higher than that of the control group (χ2 = 87.329, P = 0), while the difference in the HHV-6-positive rate between the two groups was not significant (P > 0.05). An association of EBV and HHV-6 positivity in SLE patients was found (P = 0, r = 0.38). The EBV IgM level was significantly higher in SLE patients than in healthy controls (χ2 = 25.184, P = 0). Forty-two of the 75 EBV DNA-positive specimens were positive for EBNA2 mRNA, and an association between EBV EBNA2 mRNA and anti-Sm antibody positivity was found (P = 0, r = 0.409). LMP1 mRNA was positive in 2 SLE patients with active phase, and no LMP2A mRNA expression was detected in EBV DNA-positive specimens. EBV early gene BARF1 mRNA was detected in 2 cases of EBV-positive SLE patients, and these 2 patients were also HHV-6 DNA positive. Thirty-eight patients were BcLF1 mRNA positive, and 33 of them were HHV-6 positive as well. These factors were associated (χ2 = 15.734, P = 0). The expression of the EBV immediate early gene BZLF1 was negative in all 75 EBV-positive SLE patients. CONCLUSIONS: The results suggest that EBV infection might be related to the occurrence of SLE. Although there is no direct evidence that HHV-6 infection is associated with the development of SLE, EBV and HHV-6 infection may have a coacceleration effect in SLE patients. This study provides a new theoretical and experimental basis for the study of viral etiology and the prevention and treatment of SLE.

Human herpesvirus 7 encephalitis in an immunocompetent adult and a literature review.

BACKGROUND: Human herpesvirus 7 (HHV-7) is a common virus that infects children early and is accompanied by lifelong latency in cells, which is easy to reactivate in immunodeficient adults, but the underlying pathological mechanism is uncertain in immunocompetent adults without peculiar past medical history. Even though the clinical manifestation of the encephalitis caused by HHV-7 is uncommon in immunocompetent adults, the HHV-7 infection should not be neglected for encephalitis for unknown reasons. CASE PRESENTATION: We reported here a case of HHV-7 encephalitis with epileptic seizures. While the brain computer tomography was standard, electroencephalography displayed slow waves in the temporal and bilateral frontal areas, then HHV-7 DNA was detected in the metagenomic next-generation sequencing of cerebrospinal fluid. Fortunately, the patient recovered after treatment and was discharged 2 months later. We also collected the related cases and explored a better way to illuminate the underlying mechanism. CONCLUSION: The case indicates clinicians should memorize HHV-7 as an unusual etiology of encephalitis to make an early diagnosis and therapy.

Human herpesvirus 6 DNA was not detected in a brain specimen from a patient with mesial temporal sclerosis after status epilepticus due to human herpesvirus 6 infection.

We performed virological analysis of resected brain tissues from a patient with temporal lobe epilepsy associated with mesial temporal sclerosis after febrile status epilepticus caused by human herpesvirus 6 infection. The patient had febrile status epilepticus at 9 months of age associated with human herpesvirus 6 infection. Magnetic resonance imaging revealed reduced water diffusion in the right temporal lobe and hippocampus. Polymerase chain reaction analysis detected 1.6 × 105 copies/µg of human herpesvirus 6 DNA in whole blood, but none in the cerebrospinal fluid. The patient developed temporal lobe epilepsy associated with mesial temporal sclerosis at 67 months of age, necessitating surgical treatment. Anterior temporal lobectomy was performed at 171 months of age. Real-time polymerase chain reaction analysis of resected brain tissues revealed no viral DNA. In our patient, human herpesvirus 6 infection triggered febrile status epilepticus, while direct evidence to prove contribution of HHV-6 to the development of MTS was not obtained.

Association between human herpesvirus 6 (HHV-6) and cognitive function in the elderly population in Shenzhen, China.

AIM: Human herpesvirus 6 (HHV-6) is neurophilic, and its relationship with Alzheimer's disease (AD) remains controversial. This study aimed to examine the relationships between HHV-6 and cognitive abilities in elderly people aged 60 years or above from communities in Shenzhen. METHODS: We recruited participants from 10 community health service centers in Shenzhen. Participants were divided into case and control groups according to Mini-Mental State Examination (MMSE) scale standards and were included in this study with 1:1 matching based on sex and age (± 3 years). The HHV-6 gene was detected by real-time fluorescent quantitative PCR, and the HHV-6 copy number was quantified. RESULTS: A total of 580 participants (cases, n = 290; controls, n = 290), matched for gender and age was included in this study. A positive HHV-6 test was not associated with a significant difference in global cognitive performance (ORadjusted = 1.651, 95% CI = 0.671-4.062). After adjusting for gender, age, education, Pittsburgh Sleep Quality Index (PSQI) score, homocysteine (Hcy) and glycosylated hemoglobin (HbA1c), the results of multiple linear regression showed that there was a statistically negative correlation between HHV-6 copy number and orientation (ßadjusted = -0.974, p = 0.013), attention and calculation (ßadjusted = -1.840, p < 0.001), and language (ßadjusted = -2.267, p < 0.001). The restricted cubic spline (RCS) model results showed that there was a nonlinear dose-response relationship between HHV-6 log10-transformed copies and orientation (poverall = 0.003, pnonliner = 0.045), attention and calculation (poverall < 0.001, pnonliner < 0.001), and language (poverall < 0.001, pnonliner = 0.016). CONCLUSIONS: HHV-6 infection significantly associated with orientation, attention and calculation, and language in elderly individuals.

Case Report: Overlapping Syndrome of Anti-NMDAR Encephalitis and MOG Inflammatory Demyelinating Disease in a Patient With Human Herpesviruses 7 Infection.

Objectives: This study reported a case of overlapping anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and myelin oligodendrocyte glycoprotein (MOG) inflammatory demyelinating disease with human herpesviruses 7 (HHV-7) infection. Methods: The detailed clinical characteristics, neuroimaging features, and outcomes of the patient were collected. Polymerase chain reaction (PCR), cell-based assay (CBA) and the tissue-based indirect immunofluorescence assay (TBA) were used for diagnosis. Results: The clinical manifestations included headache, dizziness, fever, optic neuritis, and epileptic-seizures. Brain magnetic resonance imaging (MRI) showed hyperintensities involving the left frontal, orbital gyrus and bilateral optic nerve with substantial contrast enhancement. Moreover, test for HHV-7 DNA by using the next generation sequencing metagenomics and polymerase chain reaction showed positive result in CSF but not in the serum samples. Anti-HHV-7 IgM and IgG antibodies were detected in both the serum and cerebrospinal fluid. NMDAR antibodies (1:10) were found positive in the patient's CSF by a cell-based assay, and MOG antibodies were positive in the serum (1:10) and CSF (1:32). The patient appeared to respond well to immune therapy and it was found that the clinical symptoms including epileptic-seizure as well as headache were relieved and cerebral lesions almost disappeared after the treatment. However, his vision was not completely restored even at the 8-month follow-up, especially the vision in his right eye which was more seriously damaged. Discussion: We report a rare case of MOG antibodies and anti-NMDAR encephalitis overlapping syndrome (MNOS) with HHV-7 infection for the first time. The possibility of MNOS needs be considered when optic neuritis occurs in the patients diagnosed with anti-NMDAR encephalitis. Besides, immunotherapy should be initiated as early as possible to improve the treatment outcomes and facilitate complete cure.

Autoimmune Neutropenia Associated With HHV-6 Virus Infection: A Case Report.

Background: Autoimmune neutropenia (AIN) is divided into primary and secondary forms. The former is more prevalent in children and is usually a self-limiting disease. Secondary AIN is more common in adults and often occurs in the setting of another autoimmune disorder or secondary to infections, malignancies or medications. Several viral and bacterial pathogens were described to trigger AIN. Here we report a case of AIN in an adult woman associated with human herpesvirus-6 (HHV-6) infection. Case Presentation: We report a case of AIN in an adult woman associated with HHV-6 infection. The patient presented to the emergency department with fever and painful genital ulcers. Upon arrival, her laboratory workup demonstrated severe neutropenia and elevated inflammatory markers. She was hospitalized and underwent a thorough infectious, hematological, autoimmune and inflammatory workup. Malignancy was also excluded using an advanced whole body radiological scan. Serological tests confirmed the presence of both acute and chronic types of HHV-6 antibodies, at very high titers. Polymerase chain reaction demonstrated a numerous copies of the virus in the patient's blood. Specific immunofluorescence test confirmed the diagnosis of autoimmune neutropenia. Conclusion: Secondary AIN is a rare disease that may affect all range of ages. The adult type is a challenging disorder that has different etiologies and may be triggered by a variable infectious pathogen. The finding of HHV-6 as a possible culprit pathogen may warrant physicians into widening the evaluation and include HHV-6 in the analysis.

Human Herpes Virus 7-related encephalopathy in children.

BACKGROUND: Primary HHV7 infection is almost ubiquitous, and it can present as exanthema subitem. Little is known on the clinical relevance of HHV7 neuroinvasion in immunocompetent children. METHODS: We describe 12 patients (median age 9.45 years, 50% males) with acute encephalopathy and active HHV7 infection. In all patients, HHV7-DNA was detected on cerebrospinal fluid (CSF) by RT-PCR. RESULTS: 7/12 patients had meningoencephalitis (two with ADEM and one with MOG antibody-associated CIS); 5/12 showed acute neuropsychiatric symptoms. EEG showed anomalies exclusively in patients with meningoencephalitis. Six patients had RMN anomalies. CSF HHV7 copies ranged between 20 and 3,500 copies/mL (median 66 copies/mL) and mean HHV7 CSF/blood ratio was 0.75. Outcome was favorable in all children, although 3/12 had minor neurobehavioral sequelae. Mean follow-up period of 5.2 months. CONCLUSIONS: HHV7 can determine neuroinvasion in immunocompetent children, leading to acute encephalopathy. Blood-brain barrier damage and high CSF/blood viral copies ratio correlated with a more severe presentation. We speculate on the importance of immune-mediated mechanisms in provoking clinical features.

Acute autonomic dysregulation due to HHV-6 encephalitis in an immunocompromised patient: a case report and literature review.

Human herpesvirus-6 (HHV-6), in particularly HHV-6B, can reactivate in immunocompromised patients. Especially after stem cell transplantation, reactivation of HHV-6 can cause complications, such as limbic encephalitis. We present a case of a 61-year-old man with B-cell non-Hodgkin lymphoma. He presented with subacute lethargy, confusion and hyperhidrosis. Following this, we will give a short review of the literature considering clinical and technical features as well as treatment options.