Clinical and molecular biological studies in recurrent Aphthous Stomatitis
The aim of these studies was to research different aspects of the pathogenesis and therapeutic features of recurrent aphthous stomatitis. In support of the involvement of viruses in the aetiology of recurrent aphthous stomatitis, the nested PCR and assays of ELISA and IFA were employed. Results of PCR investigations showed that HHV-6 DNA was present in 29 per cent of aphthous lesions. Using ELISA, specific IgG antibodies against HHV-6 were detected in 96.7 per cent of all serum samples with no significant difference between aphthous patients, oral lichen planus or control subjects. Specific IgM antibodies against HHV-6 were found in a higher prevalence rate in aphthous samples compared with the two other groups: a significant difference of p=0.01 was found between sera of aphthous patients compared with healthy controls. HCMV and VZV DNA were not detected in aphthous samples. Also serological findings did not show any significant increase in the prevalence of specific IgG antibodies against these two viruses. Serum IgM antibodies against HCMV were positive in a small number of samples with no difference between groups and IgM antibody against VZV was not positive in any serum samples. These data fail to show that recurrent aphthous stomatitis can be a manifestation of VZV or HCMV infection or reactivation. However, the possibility of involvement of HHV-6 is raised by the present studies. The possible involvement of Mycobacterium paratuberculosis was examined by the nested PCR investigations. Although mycobacterial DNA was detected only in four biopsy samples of aphthous patients and in none of the oral lichen planus patients or controls, this difference was not significant and more research is necessary to confirm such involvement.