Association of human herpesvirus 6 subtypes with symptomatic apical periodontitis

Herpesviruses and MicroRNAs: New Pathogenesis Factors in Oral Infection and Disease?

The oral cavity incessantly encounters a plethora of microorganisms. Effective and efficient oral innate and adaptive immune responses are incumbent to maintain healthy mucosa. A higher prevalence of Human Herpesviruses (HHV), a family of large enveloped DNA viruses, has been reported in multiple oral inflammatory diseases suggesting their involvement in disease progression. However, the viral components contributing to oral disease remain obscure. MicroRNAs (miRNA) are non-protein coding, single stranded ribonucleic acid (RNA) molecules that post-transcriptionally regulate diverse messenger RNAs. Thus, miRNAs can control large repertoire of biological processes. Changes in miRNA expression are associated with various oral infections and diseases. Cellular miRNAs can act as pro- or anti-viral factors and dysregulation of host miRNA expression occurs during herpesviruses infection. This strongly suggest a critical role of cellular miRNAs in host-herpesvirus interaction. Interestingly, HHV also encode multiple miRNAs (called viral miRNAs) that may play key role in host-pathogen interaction by modulating both host biological pathways and controlling viral life cycle. Recent studies from our laboratory have identified viral miRNAs (v-miRs) in diseased oral tissue biopsies and demonstrate their immunomodulatory roles. This review discusses the association of miRNAs (both host and viral) and herpesviruses in the pathogenesis of oral inflammatory diseases.

LACK OF ASSOCIATION BETWEEN HERPESVIRUS DETECTION IN SALIVA AND GINGIVITIS IN HIV‑INFECTED CHILDREN

The aims of this study were to compare the detection of human herpesviruses (HHVs) in the saliva of HIV-infected and healthy control children, and to evaluate associations between viral infection and gingivitis and immunodeficiency. Saliva samples were collected from 48 HIV-infected and 48 healthy control children. Clinical and laboratory data were collected during dental visits and from medical records. A trained dentist determined gingival indices and extension of gingivitis. Saliva samples were tested for herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) by nested polymerase chain reaction assays. Thirty-five HIV-infected and 16 control children had gingivitis. Seventeen (35.4%) HIV-infected children and 13 (27%) control children were positive for HHVs. CMV was the most commonly detected HHV in both groups (HIV-infected, 25%; control, 12.5%), followed by HSV-1 (6.2% in both groups) and HSV-2 (HIV-infected, 4.2%; control, 8.3%). The presence of HHVs in saliva was not associated with the presence of gingivitis in HIV-1-infected children (p = 0.104) or healthy control children (p = 0.251), or with immunosuppression in HIV-infected individuals (p = 0.447). Gingivitis was correlated with HIV infection (p = 0.0001). These results suggest that asymptomatic salivary detection of HHVs is common in HIV-infected and healthy children, and that it is not associated with gingivitis.

Viruses in pulp and periapical inflammation: a review

The presence of viruses in endodontic disease has been studied in the last decade. Their presence is associated with periapical radiolucency and with clinical findings, such as pain. The aim of this review is to analyze the scientific evidence currently published about viruses in pulp and periapical inflammation, and its possible clinical implications. A literature review was carried out using the Medline/Pubmed database. The search was performed, in English and Spanish, using the following keyword combinations: virus AND endodontic; virus AND periapical; virus AND pulpitis; herpesvirus AND periapical; papillomavirus AND periapical. We subsequently selected the most relevant studies, which complied with the search criterion. A total of 21 articles were included, of which 18 detected the present of viruses in the samples. In 3 of the studies, viral presence was not found in the samples studied. The Epstein-Barr virus was found in about 41 % of cases compared to controls, in which it was present in about 2 %. The main association between viruses and endodontic pathosis is between Cytomegalovirus and Epstein-Barr virus; these are found in 114 of the 406 samples of different endodontic pathosis. Some evidence supports that the Epstein-Barr virus is present in a significant number of endodontic diseases, without exact knowledge of their action in these diseases.