Significance of Beta-Herpesviruses (HHV-6, HHV-7) Infection under the Conditions of Immune Disorders

Research output: Types of ThesisDoctoral Thesis


Human herpesvirus-6 (HHV-6) and human herpesvirus-7 (HHV-7) are ubiquitous beta-herpesviruses widely distributed in the general population. They primary infection usually occurs in the early years of life and remains latent in the host for the lifelong period. At present there are numbers of studies trying to find and evaluate the role of beta-herpesviruses infection in the development of various chronic diseases, but still there is no final answer to this question. It could be due to ther ubiquitous nature and different mechanisms of interference with the host organism that these viruses are using. The aim of the present study was to ascertain the involvement of beta-herpesviruses infection in the pathogenesis and clinical course of chronic diseases and development of post-transplant complications due to their ability to change host-pathogen interaction. Three groups of patients were enrolled in this study: renal transplant recipients with immunosuppressive therapy (after renal transplantation), patients with underlying disease (gastrointestinal cancer) and patients with autoimmune process (autoimmune thyroiditis). Practically healthy blood donors and thyroid tissue autopsy specimens were included as a control. Qualitative and quantitative polymerase chain reactions (PCR) were used to detect presence of viral genomic sequences, infection activity stage, HHV-6 strain and viral load. Viral specific antibodies were detected by enzyme-linked immunosorbent assay (ELISA) and chemiluminiscence test, cytokines’ expression level – by ELISA, immunocompetent cells’ subpopulations – by Becton Dickinson (USA) laser flow cyto-fluorimeter, sorted and further analysed. The results showed various frequency rates and activity stages of HHV-6 and HHV-7 infection in these three patient groups with different immune system dysfunctions, as well as differences in immune system responses and changes in immunocompetent cells’ populations. Comparison of three mentioned patients’ groups revealed that patients with anti-rejection medical treatment had the most severe immunosuppression and higher beta-herpesvirus activation risk leading to the development of different complications. The lowest beta-herpesviruses infection frequency and activation rate was detected in patients with gastrointestinal cancer, at the same time strong association of HHV-6 and HHV-7 active infection with lymphopenia was demonstrated and higher mortality rate was observed between the patients with lymphopenia than without it. In patients with autoimmune thyroiditis high HHV-6 and HHV-7 infection frequency was found, indicating that viral infection could be implicated in the disease development. Moreover, higher viral load in thyroid tissue as in whole blood of autoimmune thyroiditis patients’ was an additional evidence of HHV-6 involvement in the disease development and was as indicator that thyroid gland is one of the places of HHV-6 latency creating a precondition for autoimmune process development.
Original languageEnglish
  • Murovska, Modra, First/Primary/Lead supervisor
  • Capenko, S., Second/Co-supervisor, External person
Place of PublicationRiga
Publication statusPublished - 2014


  • Doctoral Thesis

Field of Science*

  • 3.2 Clinical medicine

Publication Type*

  • 4. Doctoral Thesis


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