Treatment of Chronic Reactivation HHV-6 Infection with Valganciclovir
Irina A. Rakityanskaya*, Tatiana S. Ryabova and Anastasiya A. Kalashnikova
ABSTRACT
Research Objective: Currently, there are no officially approved antiviral drugs used for the treatment of chronic herpes virus type 6 (HHV-6). Ganciclovir, a nucleoside analog synthesized in 1980 by Kelvin Kenneth Ogilvie and patented for the treatment of cytomegalovirus infection, is widely studied and used for the treatment of HHV-6 infection. In 1988, the drug was approved for medical use. Among all antiviral drugs discovered to date, ganciclovir has the strongest inhibitory effect on the activity of HHV-6.
Aim: The research was to study the effectiveness of valganciclovir in the treatment of patients with reactivation of HHV-6 infection.
Material and Methods: The study was conducted in 50 patients with reactivated chronic HHV-6 infection. The ratio of women to men was 3:1 (women – 37, men – 13). The average age of the patients was 34.12 ±1.24 years (95% CI: 31.68 - 36.67). The duration of the disease was 2.57 ± 0.15 years (95% CI: 2.28 – 2.90). HHV-6 infection was confirmed by the presence of HHV6 DNA copies in saliva samples, the presence of IgG antibodies to HHV6 in the serum, and severe clinical symptoms. All patients received valganciclovir therapy at a daily dose of 900 mg for 6 months. To assess the effectiveness of therapy, HHV-6 DNA copy number analysis in saliva samples, IFN-α and IFN-γ production levels, and changes in clinical symptoms were performed monthly.
Results: A significant reduction in DNA copy number was demonstrated after three months, by 39.62% of the baseline HHV6 DNA copy number (from 1175.40 ± 224.23 to 709.72 ± 104.84 copies/ml, p = 0.001), and after six months, by 53.45% (from 1175.40 ± 224.23 to 547.20 ± 74.88 copies/ml, p = 0.001). A decrease in induced IFN-α production and normal levels of serum, spontaneous, and induced IFN-γ were detected. After completion of valganciclovir therapy, all patients continued to experience some isolated complaints. However, therapy was discontinued after 6 months, as the patients’ condition became stable by the end of the fifth to the beginning of the sixth month of therapy. The majority of patients (72% (36/50)) rated their condition by the end of therapy as “satisfactory,” and 28% (14/50) as “good,” without any significant complaints. Patients ated the effect of the treatment as “positive.”
Conclusion: Long-term valganciclovir therapy for chronic HHV6 infection significantly reduces the number of DNA copies in saliva samples, but does not completely eliminate the DNA copy number. A significant reduction in all clinical complaints was demonstrated after 6 months of therapy.
