Comparative evaluation of the presence of Epstein-Barr virus in common leukoplakia, oral hairy leukoplakia and healthy mucosa by polymerase chain reaction (PCR)

Although leukoplakia is not associated with any pathologic diagnosis، it is considered a premalignant or precancerous lesion. Oral hairy leukoplakia (OHL) is one of the most common diseases which is induced by Epstein-Barr virus in immunocompromised patients، such as those with AIDS. The aim of this study was to evaluate presence of EBV in patients with common leukoplakia، hairy leukoplakia and healthy mucosa. In this retrospective case/control study، 18 samples of common leukoplakia، 12 OHL lesions and 30 samples of healthy mucosa (as controls) were selected from paraffin blocks of previous biopsies. DNA was isolated by chelex-100 method and PCR was carried out. Data was analyzed by chi-squared and Fisher’s exact tests using SPSS (α=0. 05). Ten samples of OHL (83%)، 8 samples of common leukoplakia (44%) and 6 samples of healthy mucosa (20%) were EBV-positive. Fisher’s exact test showed that frequency distributions of EBV had significant differences between the groups and also between OHL and healthy mucosa (p value = 0. 001). Chi-Squared test revealed significant differences in the frequency distributions of EBV between common leukoplakia and OHL (p value = 0. 033). In comparison between common leukoplakia and healthy mucosa، frequency distributions of EBV did not exhibit significant differences (p value = 0. 071). Under the limitations of the present study، the frequency distributions of EBV in OHL were significantly higher than those in the two other groups، suggesting an important role of EBV in the pathogenesis of OHL and confirming the results of previous studies.