Epstein-Barr virus is associated with gastric carcinoma. There has been no study about the frequency of Epstein Barr virus associated gastric carcinoma (EBVaGC) in Algeria an endemic area of nasopharyngeal carcinoma. The objective of this study is to investigate the prevalence of EBVaGC among Algerian patients and to define EBV latency patterns in this tumor.The expression of latent membrane protein-1 (LMP-1) was evaluated in EBV positive cases with specific monoclonal antibodies using immunofluorescence and immunohistochemistry techniques.97 cases selected of gastric carcinoma were examined for EBV infection using fluorescence in situ hybridization assay to detect EBV-encoded small RNAs (EBER-1 and EBER-2). Combined immunofluorescence and fluorescence in situ hybridization was carried out in 15 gastric carcinoma cases to confirm the presence of EBERs and LMP-1 simultaneously. We have shown that 22 out of 97 cases (22.7%) expressed EBV. EBERs were present within the malignant epithelial cells and in precancerous lesions showing dysplasia tissue, but in none of non-neoplastic cases. In addition, LMP-1 was expressed in 8 of 22 EBV-positive simples. The expression was membranous/cytoplasmic, restricted to the malignant cells and absent in non-neoplastic tissues. Combined immunofluorescence and fluorescence in situ hybridization determined a colocalisation of EBERs and LMP-1 in gastric carcinoma cells. We conclude that the prevalence of EBVaGC is 22.7 % in Algeria with specific clinicopathologic features, and the type of latency is similar to the type of latency of nasopharyngeal carcinoma.
