Detection of Helicobacter pylori DNA in recurrent aphthous stomatitis tissue by PCR

Helicobacter pylori is recognised as being an aetiological agent of chronic active gastritis and peptic ulcer disease and has been associated with an increased risk of gastric cancer. The natural reservoir for H. pylori is un known, although the oral cavity has been the focus of much attention in thi s respect. Given the histological similarities between gastric and oral ulc eration, it seemed prudent to investigate a possible association between H, pylori and recurrent aphthous stomatitis (RAS). In this study, the potenti al involvement of H. pylori in the aetiology of RAS was investigated using the polymerase chain reaction (PCR). Biopsies from 28 RAS patients were ana lysed, in addition to 20 oral lichen planus (OLP) and 13 normal biopsies th at were used as controls. Genomic DNA was extracted from biopsies, and conf irmation of successful extraction of PCR-amplifiable DNA was achieved by ca rrying out PCR on each DNA sample with nested primers specific for the huma n beta-haemoglobin gene. PCR identification of H. pylori was carried out us ing a primer pair specific for the H. pylori 16S ribosomal RNA (rRNA) gene. Two rounds of PCR were carried out to amplify a 295-bp product, and the id entity of amplified products was confirmed by DNA sequencing. H. pylori DNA was detected in 3 of 28 (11%) RAS samples but not in any of 20 OLP and 13 normal samples. These results do not support a definitive aetiological role for H. pylori in RAS, although the possibility that H. pylori may be invol ved in a small proportion of RAS cases cannot be excluded.