What is the treatment for Human Herpesvirus 6 (HHV-6) infection?

From the Guidelines

Intravenous foscarnet or ganciclovir are recommended for treatment of HHV-6B encephalitis, with the recommended doses being 90 mg/kg twice daily for foscarnet and 5 mg/kg twice daily for ganciclovir 1. The treatment for Human Herpesvirus 6 (HHV-6) infection depends on the severity and clinical presentation of the disease.

Key Considerations

• For mild cases, supportive care is recommended, including rest, adequate hydration, and antipyretics to manage fever and discomfort.
• In severe or life-threatening cases, particularly in immunocompromised patients or those with encephalitis, antiviral medications may be necessary.
• The choice between foscarnet and ganciclovir should be dictated by the drug’s side effects and the patient’s comorbidities 1.

Antiviral Therapy

• Antiviral therapy should be administered for at least three weeks and until testing demonstrates clearance of HHV-6 DNA from blood and, if possible, cerebrospinal fluid (CSF) 1.
• Combined ganciclovir and foscarnet therapy can be considered, although the small sample size limits conclusions regarding whether combination therapy is superior to monotherapy 1.

Additional Measures

• Immunosuppressive medications should be reduced if possible to help manage HHV-6 infection 1.
• Regular monitoring of liver and kidney function is important during antiviral treatment due to potential toxicity.
• New treatment modalities for HHV-6 are being explored, including adoptive immunotherapy with virus-specific T cells, which appears to be safe and potentially effective in small, uncontrolled studies 1.

From the Research

Treatment for Human Herpesvirus 6 (HHV-6) Infection

• The antiviral compounds ganciclovir, foscarnet, and cidofovir are effective against active HHV-6 infections 2.
• These compounds are not formally approved for the treatment of HHV-6 infections, but they are used to treat the infection due to their efficacy against the virus 2, 3, 4.
• Combination therapy with foscarnet and ganciclovir may reduce sequelae, but not mortality, secondary to HHV-6 encephalitis 5.
• Ganciclovir, foscarnet, or cidofovir have been used to treat clinically significant tissue-invasive HHV-6 infections in liver transplant patients 6.
• The search for antiviral drugs effective against HHV-6-associated diseases is ongoing, with various compounds being investigated, including nucleoside and non-nucleoside analogues 4.

Antiviral Compounds

• Ganciclovir: effective against active HHV-6 infections, but not formally approved for treatment 2, 3, 5.
• Foscarnet: effective against active HHV-6 infections, particularly in combination with ganciclovir 2, 3, 5.
• Cidofovir: effective against active HHV-6 infections, but its use is limited due to its potential toxicity 2, 3, 4.

Treatment Outcomes

• The proportion of patients with encephalitis who died or developed sequelae was lower among recipients of combination therapy with foscarnet and ganciclovir compared to those who received monotherapy 5.
• Non-cord blood transplant was identified as an independent risk factor for developing sequelae after receiving ganciclovir monotherapy 5.
• There was no difference in mortality between patients who received combination therapy and those who received monotherapy 5.