Inherited chromosomally-integrated human herpes virus 6 confounding test results in a patient with myelitis and optic neuritis - A case report

A case of the 'perfect storm' of myelin oligodendrocyte glycoprotein (MOG) antibody-mediated myelitis, human herpesvirus 6 (HHV-6) reactivation, and COVID-19 infection was reported in 2021. This article reports a case of a similarly observed clinical triad, but with a different conclusion and explanation supported by laboratory test results and evidence from our literature review.

Laboratory assessment of a multi-target assay for the rapid detection of viruses causing vesicular diseases

BACKGROUND

The recent mpox outbreak has highlighted the need to rapidly diagnose the causative agents of viral vesicular disease to inform treatment and control measures. Common causes of vesicular disease include Monkeypox virus (MPXV), clades I and II, Herpes simplex viruses Type 1 and Type 2 (HSV-1, HSV-2), human herpes virus 6 (HHV-6), Varicella-zoster virus (VZV) and Enteroviruses (EVs). Here, we assessed a syndromic viral vesicular panel for rapid and simultaneous detection of these 7 targets in a single cartridge.

OBJECTIVE

The aim of this study was to evaluate the QIAStat-Dx ® viral vesicular (VV) panel and compare with laboratory developed tests (LDTs). Limit of detection, inter-run variability, cross-reactivity and specificity were assessed. Positive and negative percent agreement, and correlation between assays was determined using 124 clinical samples from multiple anatomical sites.

RESULTS

The overall concordance between the QIAstat and LDTs was 96%. Positive percent agreement was 82% for HHV-6, 89% for HSV-1 and 100% for MPXV, HSV-2, EV and VZV. Negative percent agreement was 100% for all targets assessed. There was no cross-reactivity with Vaccinia, Orf, Molluscum contagiosum viruses, and a pooled respiratory panel.

CONCLUSION

The QIAstat VV multi-target syndromic panel combine ease of use, rapid turnaround, good sensitivity and specificity for enhanced diagnosis, clinical care and public health responses.

Fatal human herpes virus 6B myocarditis: Postmortem diagnosis of HHV-6B based on CD134+ T-cell tropism

Human herpes virus 6 (HHV-6) is one of the most important pathogens of viral myocarditis, and is often responsible for sudden death in young adults. A 59-year-old immunocompetent man died of serious lymphocytic myocarditis, and his peripheral blood sample showed HHV-6 DNAemia. Recently, HHV-6 cell entry and reactivation have been suggested to be regulated by the expression of specific CD receptors on T lymphocytes. Here, we report a case of HHV-6 myocarditis diagnosed using an experimental method focused on this unique cell tropism. The interaction between HHV-6 and CD expression was assessed using an immunofluorescence assay. Colocalization between HHV-6B and CD134 was detected in lymphocytes infiltrating the myocardium, which was highly suggestive of an active HHV-6B infection and could be a useful criterion for postmortem diagnosis of HHV-6B myocarditis in the acute phase.

Oropharyngeal shedding of herpesviruses before and after BNT162b2 mRNA vaccination against COVID-19

INTRODUCTION

Concerns were raised over an increase in Bell's palsy, herpes simplex and herpes zoster after BNT162b2 vaccination, all are manifestations of herpesviruses reactivation. As herpesviruses commonly reactivate in the oropharynx, we have hypothesized that oropharyngeal shedding of herpesviruses will increase after vaccination.

METHODS

Immune-competent Adults, excluding those using topical steroids or manifesting symptomatic herpesvirus infection, were sampled before BNT162b2 vaccination and one week after. Herpesviruses 1-7 shedding was tested with a multiplexed PCR.

RESULTS

In 103 paired samples the prevalence of herpesviruses was similar before and after vaccination: HSV1, 3.9% vs. 5.8% (p = 0.75); HSV2, 0% vs. 1% (p = not applicable, NA); VZV, 0% vs. 0% (p = NA); EBV, 14.6% vs. 17.5% (p = 0.63); CMV, 0% vs. 0% (p = NA); HHV6, 4.9% vs. 7.8% (p = 0.55); HHV7, 71.8% vs. 72.8% (p = 1); any herpesvirus, 73.8% vs. 74.8% (p = 1).

DISCUSSION

We did not find evidence for increased oropharyngeal reactivation of herpesviruses one week after BNT162b2.

A rare case of recurrent HHV6 encephalitis in an immunocompetent adult

Human Herpesvirus 6 (HHV-6) is a virus known to cause mild infection in children. In adults, HHV-6 reactivation has been described in immunocompromised individuals.Rarely, viral reactivation occurs in immunocompetent adults causing significant disease and morbidity. The use of certain medications, like amoxicillin, has been found to induce HHV-6 reaction in a number of cases. We report a 63-year-old immunocompetent female who presented with headache, fever and altered mental status. Past medical history included two bouts of HHV-6 encephalitis treated at external facilities. According to her medical history, both episodes of encephalitis were preceded by amoxicillin use. Her lumbar puncture analysis was consistent with viral etiology and a cerebrospinal fluid (CSF) PCR was positive for HHV-6. She was successfully treated with intravenous ganciclovir. It is important to keep a broad differential diagnosis in mind when approaching encephalitis in adults, and to be aware of unusual triggers for viral reactivation. Clinicians who suspect the infection in the correct clinical setting can successfully treat patients with recurrent HHV-6.

Association of HHV-6 with Hodgkin and non Hodgkin lymphoma

BACKGROUND AND OBJECTIVES

Human Herpes 6 virus (HHV-6) could remain latent and chronic in the host cells after primary infection. HHV-6 genome encodes certain transactivation proteins which may results in development of malignant lymphoma. The association of human herpes six virus (HHV-6) infection and Hodgkin and Non-Hodgkin lymphomas is strongly supported by epidemiological studies. The aim of this study was to determine the prevalence of HHV-6 among the patients with Hodgkin, Non-Hodgkin's lymphoma.

MATERIALS AND METHODS

Overall 44 blocks of formalin-fixed, paraffin-embedded of the patients including 22(50%) Hodgkin and 22(50%) Non-Hodgkin Lymphoma were collected. Initially the section of 5μm-thickness were prepared from the formalin-fixed, paraffin-embedded tissue blocks. Then the deparaphinazation was carried out for each sample. The DNA was extracted, followed by nested PCR for detection of HHV-6. Based on PCR product size and sequencing, the HHV-6 A or B subtypes were characterized.

RESULTS

12/22(54.54%) cases of Hodgkin and 8/22 (36.36%) Non-Hodgkin's lymphoma were shown as positive for HHV-6. Out of 12 positive HHV-6 in Hodgkin lymphoma, 10 patients (45.45%) belonged to variant A while 2 cases (9.09%) were found positive for both HHV-6A and HHV-6B. All the Non Hodgkin samples (n=8, 36.36%) showed positive for HHV-6 variant A.

CONCLUSION

High prevalence of HHV-6 was found among the patients with Hodgkin and Non-Hodgkin's lymphoma. Two patients with Hodgkin lymphoma had mixed HHV-6A and HHV-6B infections. It is recommended patients with Hodgkin and Non-Hodgkin should be screened for HHV-6 detection before chemotherapy.

HHV-6 infection after allogeneic hematopoietic stem cell transplantation: From chromosomal integration to viral co-infections and T-cell reconstitution patterns

OBJECTIVES

Human herpes virus 6 (HHV-6) can reactivate after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and may be associated with significant clinical manifestations.

METHODS

Case control study of HHV-6 infections after allo-HSCT. Chromosomal integration (ciHHV-6) for viral loads ≥ 5.5-log10 copies/mL was investigated. Viral co-infections, T-cell recovery, risk factors and outcome were compared in HHV-6- and non-HHV-6-infected patients. Antiviral treatment strategies were reviewed.

RESULTS

Among 366 adult allo-HSCT recipients, 75 HHV-6 infections occurred. Three (4%) recipients were ciHHV-6. HHV-6 infections were associated with CMV (p = 0.05; sdHR 1.73, CI 0.99-3.02) and/or BKV infections (p < 0.0001; sdHR 4.63, CI 2.04-10.53) but not EBV reactivation (p = 0.34). A slower CD8+ T-cells recovery was observed until 6 months after allo-HSCT in the HHV-6-infected group (p < 0.001), independently of acute and/or chronic graft-versus-host disease. The overall probability of survival after allo-HSCT was diminished for active HHV-6-infected patients (p = 0.0326). Cord blood unit recipients had a higher risk of developing HHV-6 infection compared to bone marrow recipients (p = 0.0007; sdHR 3.82, CI 1.76-8.27). Anti-HHV-6 treatment achieved complete response in only 2/3 of the cases.

CONCLUSIONS

In this series of allo-HSCT recipients, 4% were ciHHV-6, active HHV-6 infection was likely associated with CMV and BKV co-reactivations, delayed CD8+ T-cell recovery and poorer outcome.

A Randomized, Double-blind, Placebo-Controlled Study of Efficacy of Oral Acyclovir in the Treatment of Pityriasis Rosea

BACKGROUND

Pityriasis rosea is an acute self-limiting skin disorder of unknown aetiology. Recently human herpes virus 6 and 7 has been hypothesized to be the cause of pityriasis rosea.

OBJECTIVE

To determine the efficacy of acyclovir, an anti-viral drug, in the treatment of pityriasis rosea.

MATERIALS AND METHODS

A randomized, double-blind, placebo-controlled study of efficacy of oral acyclovir in the treatment of pityriasis rosea was conducted on 73 patients. Thirty eight randomly selected patients were started on oral acyclovir. Thirty-five patients were prescribed placebo. The patients as well as the chief investigator were unaware of the therapeutic group to which patients belonged (acyclovir or placebo). Patients in both the groups were evaluated clinically after 7 and 14 days following the first visit and the data were analysed.

RESULTS

Follow up data of 60 patients was available and these were included in the statistical analysis. 53.33% and 86.66% of the patients belonging to the acyclovir group showed complete resolution on the 7(th) day and 14(th) day respectively following the first visit compared to 10% and 33.33% of patients from the placebo group. The findings were statistically significant.

CONCLUSION

The study showed that high dose acyclovir is effective in the treatment of pityriasis rosea.

Acute liver failure caused by drug-induced hypersensitivity syndrome associated with hyperferritinemia

Drug-induced hypersensitivity syndrome (DIHS) is a severe reaction usually characterized by fever, rash, and multiorgan failure, occurring 2-6 wk after drug introduction. It is an immune-mediated reaction involving macrophage and T-lymphocyte activation and cytokine release. A 54-year-old woman was diagnosed with rheumatic arthritis and initiated salazosulfapyridine by mouth. About 10 d later, she had a high fever, skin rash and liver dysfunction. She was admitted to hospital and diagnosed with a drug eruption. She was treated with oral prednisolone 30 mg/d; however, she developed high fever again and her blood tests showed acute liver failure and cytopenia associated with hyperferritinemia. She was diagnosed with acute liver failure and hemophagocytosis caused by DIHS. She was transferred to the Department of Medicine and Bioregulatory Science, Kyushu University, where she was treated with arterial steroid injection therapy. Following this treatment, her liver function improved and serum ferritin immediately decreased. We hypothesized that an immune-mediated reaction in DIHS may have generated over-activation of macrophages and T-lymphocytes, followed by a cytokine storm that affected various organs. The measurement of serum ferritin might be a useful marker of the severity of DIHS.

Impact of human herpes virus 6 in liver transplantation

Human herpes virus 6 (HHV-6) infects > 95% of humans. Primary infection which occurs mostly during the first 2 years of life in the form of roseola infantum, non-specific febrile illness, or an asymptomatic illness, results in latency. Reactivation of latent HHV-6 is common after liver transplantation. Since the majority of human beings harbor the latent virus, HHV-6 infections after liver transplantation are most probably caused by endogenous reactivation or superinfection. In a minority of cases, primary HHV-6 infection may occur when an HHV-6-seronegative individual receives a liver allograft from an HHV-6-seropositive donor. The vast majority of HHV-6 infections after liver transplantation are asymptomatic. Only in a minority of cases, when HHV-6 causes a febrile illness associated with rash and myelosuppression, hepatitis, gastroenteritis, pneumonitis, and encephalitis after liver transplantation. In addition, HHV-6 has been implicated in a variety of indirect effects, such as allograft rejection and increased predisposition to and severity of other infections, including cytomegalovirus, hepatitis C virus, and opportunistic fungi. Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6, there is currently no recommended HHV-6-specific approach prevention after liver transplantation. Asymptomatic HHV-6 infection does not require antiviral treatment, while treatment of established HHV-6 disease is treated with intravenous ganciclovir, foscarnet, or cidofovir and this should be complemented by a reduction in immunosuppression.